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181 Posts
Discussion Starter · #22 ·
absolutely love this build and documentation - just like all your past builds...

which CSL roof did you use?

P.S. still waiting on the replacement driveshaft for my e36...
AJ Hartman made the roof and we did send you another new driveshaft, even though you didn't buy it from us. We support our customers, sometimes even the 2nd owners of parts. :thumbup:

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Discussion Starter · #23 ·
Project Update for August 15th, 2017: I started writing this in July and got buried with other projects and work. We have accomplished a lot on this car since the last update and I will try to show as much as possible here. I will go over the custom fuel cell + fuel filler neck and oil tank, along with the mounting structure and fire proof enclosures for all of that.

We also will cover the aftermarket front bumper cover install as well as the structures built to hold that and twin oil coolers. There were Lexan rear side windows and back window added. And we built some really big ass flares to cover the big ass tires. Lets touch on those first!


This section could be huge, but go read the flare section in my June 9th post in our E46 330 build thread, and we can all save some time. In that post I cover the flaring options and installation techniques, and even reference this car's flare job.

As I showed last time, we are building this E46 M3 around what I call "GOD'S TIRE SET" - a 335mm wide front and 345mm rear Hoosier A7 DOT tire setup. I've run these tires successfully on our TT3 Mustang (above left) and even briefly on our 92 Corvette (above right), and I'm building my new C6 Z06 project around the same set of tires too. I say if something works, stick with it!

It took me decades of dabbling in "wide tires" before I managed to work my way up to this mega-sized set. We progressed the wide wheel/tire thing on our STU classed BMW E36 M3 in 2006 (running 18x10" wheels under stock fenders), then went to 315mm tires on the Alpha E36 LS1 (above right). Our GRM Challenge winning E30 V8 got 18x11" wheels and mega-sized box flares after that.

We were already stuffing 18x10" wheels and 285/30/18 tires under BMW E46 cars ten years ago

The most tire you can fit under stock E46 M3 fenders is roughly a 285mm front and 315mm rear. I've run 285mm square on many E46 M3s and have installed M3 fenders on non-M E46 models to be able run that tire size. But that's just not wide enough for a powerful road course car. I always ALWAYS want to run the widest tire that "a driver can afford", and this car has the power and the potential of very few, so it deserves THE BIGGEST.

Last time we had fitted the 18x13" wheels and 335F/345R tires, and they obviously had a lot of poke past the M3 rear and non-M front fenders we had stuck on the car (this chassis was purchased without front fenders). Instead of buying then just cutting up valuable OEM E46 M3 fenders we kept the ~$35 front fenders from my old 330 on there to cut and build upon. Before we started cutting metal it was time to break out the craft paper and scissors...


The front mock-up flare (above left) was designed and shaped first. We were looking for some specific aero improvements that help reduce drag (covering the front of the tire) and help create downforce (evacuating the wheel well from behind). We went over several vent shapes and decided on an extended width fender face that is open at the leading edge of the door. The rear flares would follow the same mantra but it was later revised a bit. And while aero takes precedence, the style is important for Optima D&E judging, too. Nobody wants an ugly race car.


Anyone can slap on a set of pre-made "flares" fairly quickly, and the Stance Crowd often does this without doing the necessary cutting and fabrication work underneath. The real work is in the chassis clearancing - making room for the tires to travel in the "bump" direction (up) as well as allowing the front tires to "swing" while steering. This is often why I recommend a fabricator do the initial work on any custom flare installation, and not a painter. Sometimes paint and body shops don't understand the dynamics of how a suspension works on a street or race car. They also tend to use a bit more body filler. To keep weight to a minimum and allow for maximum tire clearance we tackled the custom steel flares in-house on the E46 M3 here. We will do a complete track test before the flares ever see any bodywork/paint, too.

Left: Making room for tire clearance before the flares go on is key. Right: As is thorough testing before paint!

Cutting and welding to make room for mega wide tires is difficult to do correctly and retain a waterproof and strong unibody once you are done. I've seen some janky cutting done under some flares and they leak water inside, smoke, fuel, fire, etc. These sections that are modified really need to have an air tight seal to be FIREPROOF when complete, and this isn't something you can afford to half-ass.

Normally on a unibody car cutting the rear fenders and merging them back together is the hardest part - and this car wasn't any easier than normal. What we do is take the wider tire & wheel, remove the rear spring, and compress the rear suspension into the bump stops (ie: "full bump travel"). If the car's inner structure allows it we cut the outer fender sheet metal (sometimes 2 layers) all the way above up to clear the top of the tire at full bump.

This 345/35/18 Hoosier is a really tall tire (26.8" tall) but it was still possible to get full tire clearance and not cut into the rear inner fender beyond the centerline of the tire. We were prepared to do that, if necessary. This car needs about 3" of bump travel with the MCS RR2s and it now has it. Due to aero loading it will have some rather firm springs on track, so we might never see 3" of bump in actual driving.

The 3 layers of now cut-apart steel for the rear fender structure were hammered into place, cleared of paint and undercoating, then carefully stitch welded together via a MIG. There's no way to get to all of the factory coating on the inside sections of the sheet metal but a MIG can power through this stuff better than a TIG. Once both rear fenders were cut and welded, the areas were primed with self etching primer (needs to have "zinc" somewhere in the name) and the car was reset at ride height. It looks ugly but THAT is what needs to be done under any unibody car BEFORE you start a proper rear flare job.


I've flared a lot of BMWs and normally the front fender clearance is a breeze. You mark the highest part of the tire at full bump and trim the sheet metal fender. Done. Takes 30 minutes per side, tops. But I've never added 335mm front tires on a BMW...

Just like we had to do on our BMW E30 V8 with 18x11" fronts, this E46 M3 needed EXTENSIVE mods to the frame horn above and the chassis behind the tire to clear the 13" wide tire swinging at full lock. Large chunks of the inner fender structure were removed.

The part of the upper frame horn that was removed was replaced with some formed 18 ga steel sheet metal, shown above left. The same template and shape was used on both sides, just inverted for the right/left fenders.

The surrounding metal was cleared of paint with the pneumatic wire wheel called the Krud Buster. Awesome tool. Then this panel was stitch welded in place to tie the structure back together.

And just like how I did the same reinforcement work on the E30 (above left), Ryan added square tubing to replace some of the missing sheet metal structure on the E46 M3 (above right). All of this was TIG welded in place (way better than my E30 welding!) and the raw steel was all coated with more zinc primer. Now we are ready to add the actual flares.


We are building these flares out of 18 gauge steel with the hopes of being able to pull molds off the final set. And while we could have made them out of foam and fiberglass, we are not a composites shop. This is the best way to make a one-off set of wheel flares in-house. They will be strong and can also be used to pull molds off of afterwards.

Ryan started by adding some "landing" zones for the front flares by adding some flat sheet in the horizontal plane at the front and back of the front wheel front wheel arch opening. We will add a front "canard" portion that attaches to the front bumper cover and this landing pad will be the seam.

The wheel arch had a rolled upper edge added in the bead roller (above left). With this "skeleton" added on the outer edge of the flare the gap to the fender could be bridged.

The upper curved section of the flare was cut from steel made from transfers from the cardboard templates. These sections were then rolled and reformed in the English Wheel (above left) and the edges that meet the wheel arch were rolled in the bead roller (above right) and formed further in the shrinker stretcher (not shown).

These horizontal flare sections were fitted to the framework of the flare and fender but went back into the English Wheel a few times to be fitted.

Initially these horizontal sections were made from one piece of sheet - which was a very long, multi-curved panel. These were later were re-made in 3 pieces, to get a better curved fit. The rear section was templated with blue tape (see above left) and you can see the seams in the top/middle and at the rear third (see above right).

To create a gap at the door opening there was a "flat" section that was welded to the middle of the curve on the front flare. Finally a vertical panel tied that "flat" upper section section into the rear landing pad. This vertical panel has a curve that mimics the stock fender shape, just moved outward five inches. The total flare width at the curve is 8.25" - its pretty massive.

You can see the large vent opening at the rear of this panel which will be used to evacuate the wheel well. There are all sorts of curved and formed edges on this panel to give it strength, cleaner airflow and better looks.
The look we were going for was sort of a modified/curvier DTM flare. The entire structure shown above is attached to the fender, which can be removed as a unit.

continued below

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Discussion Starter · #25 ·
continued from above


The rear flare fabrication follows the same process as the front, starting with the front and rear "landing pads" then the formed outer arch framework.

The curved horizontal flare sections were made from multiple pieces this time to keep the curves following the bodylines better.

Ryan finished up the rear flare and they looked great - from the side (see above right). But from the rear there was something odd about the rear vent opening. There was an attempt to widen the rear fender to follow the rear taillight shape. It just... didn't look right.

Several of us stood around the rear flare one afternoon and we drew some lines in sharpie as well as blue tape. We all weighed in and together came up with a new shape.

Above shows version 2 of the rear flare. The boxy rear section was scrapped in favor of a tear drop shape to the added vertical section, which blends into the fender at the tail light. Some curved air deflectors were also mocked up in cardboard.

Once again everything shown attaches to the rear fender. There will be additional portions that tie the rear bumper cover into this flare on the back side as well as a skirt that ties into the lower front section of the rear flare - as well as the trailing lower edge of the front flare.

Everyone was happier with the look of this version so the other side was begun. With a final design locked down the second side was slightly easier to duplicate in a mirror image, pulling templates from the right side pieces to make the left side flares.

I'm happy with the look, Jason likes the airflow shapes, and Ryan likes the tire clearance - and the customer likes it all. Again, we obviously have some missing sections to tie into the flares sections at the front, middle and back, but the "wheel flares" are complete and ready for final welding then track testing before bodywork and paint.


The images below may look pretty mundane but there was a lot of thought, planning, and custom fabrication that went into these items and enclosures.

Let's break it down into sub-sections, starting with the fuel cell decision.


The stock fuel tank in the BMW E46 has both good and bad properties. Good: it is strong, compact, mounted very low in the chassis, just aft of the front seats. Under the rear seats, under sheet metal, completely sealed away from the cabin. It crashes well being in the rear middle of the car, too.

On the bad side the saddle shape makes for nasty fuel slosh in lateral loading and the "tunnel" between the two sides is too tight to fit dual 3" exhaust pipes and still keep good ground clearance. It is also plastic which means in a fire it can melt, rupture, etc. That isn't super common in crashes, but it is a possibility. Also, one side of the E46 saddle tank is much smaller than the other, as you can see above left. It is cheap and easy to just re-use this tank - which is what I did on my personal E46 330 race car.

In use a fuel cell provides a minimal anti-slosh effect due to the foam that is inside the bladder but can be designed to always pick up fuel. A fuel cell bladder is VERY tough and made to hold up very well in a motorsports crash. The bladder is mounted inside of a can that is made of steel or aluminum, with one end (usually the top) that can be unbolted, to extract the bladder for service. The bladder has to be replaced every 5 years to maintain FIA certification, so keep that in mind. The fuel cell foam can also degrade, especially when exposed to (and soaked /stored with) ethanol.

For many decades an FIA approved fuel cell was required for many road racing and hill climb (like the Pikes Peak Subaru STi above) classes, but safety improvements in modern OEM plastic fuel tanks - and their common, optimized placement under the car behind the front seats - has allowed these to be permitted in many Wheel-2-Wheel racing classes. We are building this E46 M3 for NASA Time Trial and Optima competition, so a fuel cell was not required, but it is never a bad idea. They do tend to be safer than almost any OEM fuel tank.

We talked about a custom fuel cell early on. Trunk mounting is the easiest and probably smartest move. There are many rectangular shaped fuel cells with an aluminum enclosure and kevlar bladder, like the ATL below in the 69 Camaro track build. This is mounted behind the axle just forward of the rear bumper.

I usually forego this in my own cars because I don't do wheel-to-wheel racing, but for serious builds a fuel cell is pretty standard. If packaging had permitted, we would have used an off-the-shelf fuel cell / shape and stuck it in the trunk. If possible, try to use an off-the-shelf cell. You will save mountains of packaging hassles and costs by sticking with common fuel cell shapes.

This car, being built for Optima competition, needed to be more optimized. Visible "race car" things (like a trunk mounted fuel cell) can sometimes spook the D&E judges. Besides, having a big chunk of weight in the form of 16-20 gallons of fuel mounted way out back makes for some weird polar moment issues.


Pretty early in this project we decided to make a custom fuel cell, to gain the exhaust clearance room in the tunnel, add safety, and keep the fuel load as low and centrally/rear located as possible. Putting it in/under the back seat would also leave the trunk floor area open for a diffuser - another really useful addition to get additional downforce in an Optima car (rear wings are severely limited in that series).

This custom cell was modeled somewhat around the lower shape of the right/passenger side of the OEM saddle tank, just made significantly taller. It actually holds 16 gallons all on the one side, which equals the OEM dual saddle tank's volume. We figured it would be easier to do a couple of sessions in a row on track feeding a hungry 800 hp engine if we had a full 16 gallons on board. Ryan made the "can" out of aluminum plate that was TIG welded together, with a flange on the top to be able to access the bladder inside.

The shape of the can is funky - not rectangular - and this will cost us later when we have a custom bladder is built, but the alternative is a compromise of one sort or another. Of course there is a hole in the rear seat floor to let the taller portion poke through - to get the fuel volume we needed. This hole will need to be sealed up from the cabin, and an enclosure around the fuel cell can will be needed as a firewall. That work is shown below in another sub-section.

The fuel cell can is 15" tall and sits about 5" above the rear seat floorpan, but sits no lower under the car than the OEM saddle tank. The fuel cell can is mounted inside of a mounting structure or "cage" made of 1" square steel tubing. The upper portion can be unbolted to remove the can.

The entire "cage" bolts into the rear seat area - and also holds the dry sump settling tank, which I will talk about below.


Running a dry sump oiling system is a really REALLY good idea on a car like this that has massive race tires (13.8" wide), lots of downforce, and a built race engine. And any dry sump oiling system needs an oil settling tank / reservoir.

There are two schools of thought on oil tank placement with a dry oiling system: the engine builder wants it up front RIGHT next to the engine, with minimal plumbing runs. Mounting it under the hood at the firewall is common. The chassis engineer wants this 10-14 quart oil tank at the opposite end of the chassis than the motor, to keep improve rearward weight bias. This "trunk mounting" option is somewhat less common, but it is done.

On this car we split the difference, mounting the oil tank opposite of the fuel cell, sitting behind the driver. It also pokes down through the rear seat floor, to keep the weight as low in the chassis as possible.

The shape of a dry sump tank is also important. The taller the tank the more distance the settling oil has to travel and hopefully the more baffles it can pass through to remove entrapped air. The oil that hits spinning engine parts can get whipped up like a milk shake and turn into foam. Foam doesn't "pump" well and lubricates even worse. The longer the oil has to travel inside the settling tank, the more air gets removed and the more "liquid" it becomes. So a tall/skinny tank is more advantageous than a short/fat tank. But all sorts of sizes are available to help builders package the oil tank in their application.

The tank that fed the 7.0L LS7 engine in the the factory equipped dry sump C6 Z06 was tall and skinny. One major change happened from 2007 through 2013 model run of this car was - to make the tank larger in volume, going from 6 quarts up to 9 quarts (bringing total oil capacity of engine + tank + cooler from 8 to 11 quarts). There are even larger capacity oil tank units for this OEM LS7 application from the aftermarket.

We chose an ARE tank (p/n 7025A) which has a 25.5" height and 6" diameter. This holds 2.5 gallons of oil (10 quarts) and is the "Tall and Skinny" option. These are more of a chore to package inside of a race car. We also ordered the ARE tank mount (p/n 7000) to hold the tank, which was mounted to the 1" tubular structure mounted in the back seat.

continued below

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Discussion Starter · #26 ·

As you can see it sits pretty high in the chassis but its 25.5" tall. It sticks down under the rear seat floor (through a hole) as far down as we could comfortably put it, too.

This hole of course has to be covered, but a fire proof aluminum enclosure will handle that.

continued from above


A mounting structure was built with 1" square tubing to hold the fuel cell can and dry sump tank. On top of this are the "firewall" panels that seal the passenger compartment from these hot/flammable fluids as well as the underside of the car.

The structure started out as a perimeter section of tubing and eventually lower sections were added for the fuel cell can. Then the bolt-on upper section for the can, too.

After that the bracket to hold the ARE billet oil tank mount was formed from steel sheet, with some dimple die holes to add stiffness and remove weight.


Now that the tank/cell mounting cage was bolted into the car the openings through the trunk floor needed to be sealed. There also needed to be metal coverings for the dry sump tank and fuel cell as well, to keep fluids and fire away from the cabin.

First the enclosure for the top of the fuel cell was built from more aluminum sheet.

These were cut using cardboard templates, then taped together and trimmed, tack welded and final TIG welded. This "can" mounts inside the 1" steel tubing structure.

But wait, there's more! A giant 3-piece enclosure was needed for the oil tank side. The enclosure was too tall and unwieldy to be made from 1 piece, so it's 3 pieces.

We need to make an easy to access hatch to check the oil tank levels (dipstick) and there's still a flat panel that needs to go between the two upper enclosures but for the most part it is done. They aren't exactly "pretty" to look at but they are very functional and necessary. We might add a shrubbery or something to distract the D&E judges... ;)


To lower weight we added Lexan rear quarter windows and back windows. Then we added a fuel filler neck in one of these windows, and an enclosure around the filler neck.

We sourced the rear quarter and back windows from Five Star, a race car supplier. These were mocked up on the car above to check for fit, which was very good.


One thing I didn't get this time were the weights on the glass rear window or side windows vs the Lexan bits. I did get the weights on the HARD Motorsport and OEM E46 rear side rear windows in this July post on the E46 330 TTD car, which I copied below. The Five Star bits weigh almost exactly the same but the HM bits are much easier to mount (with their optional install kit) and come with a black outline vinyl border pre-applied to the inside.

The side windows were installed first. Like most race car parts these come with no instructions - you're expected to know what you are doing.

Ryan began by marking the outer perimeter with two lines that corresponded to part of the "black border" that would be added later as well as a centerline for drilled holes. These were marked using a compass and a Sharpie, which you can see below at left. The outer protective film was left in place as to not mark up the actual Lexan plastic.

None of the factory mounting hardware was re-used. Holes were drilled equally around the perimeter of the glass that would land in the sheet metal surround of the window. Then the holes in the windows were transferred to the body and those were center punched and drilled.

M5 nutserts were installed into the sheet metal surround for each window then countersunk stainless Tinnerman washer and countersunk stainless bolts secured the window in place. This makes for flush mount, corrosion free hardware. The factory black drip rail trim was then reinstalled.


The rear window installation followed the same techniques: marked and drilled Lexan, transferred holes and drilled sheet metal, added M5 nutserts, then Tinnerman washers and countersunk M5 bolts.

Many of you readers have seen us install and use these threaded inserts or "nutserts" on many projects. We tend to use metric splined steel nutserts in M4, M5, M6 and M8 sizes, like the one shown above left. These add a threaded hole to sheet metal that is "blind" or hard to access on the backside. There are also versions for use in plastic or fiberglass panels as well. If you can work a blind rivet gun you can work a nutsert installation tool (above right).

This is how they are installed... you drill the appropriate hole (there's a chart), install the nutsert you want with the correct "grip length" (there are longer nutserts for thicker panels), then use the tool to squeeze the insert and expand the back side behind the panel. Now you have a threaded insert that is secured in place. Sure, you could install welded inserts, but that's a lot more work. We tend to use those on thicker metal, if we cannot drill/tap it for some reason, or if we need a much longer threaded length or more strength than the nutsert can support.

Like Ryan did on the same exact brand of rear window on my E46 330, we will go back and tape off then spray paint the border on both the side and rear window on this E46 M3 at a later date. This makes the windows look a lot less "race car" and hides the visible sheet metal underneath.

We will be blowing the car apart for paint after the first track test, so we will likely add the painted borders (and some RTV sealant) to these windows then. For now they were secured in place with bolts only.

continued below

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Discussion Starter · #27 ·
continued from above


At this step we show the plumbing from fuel filler cap on the right rear window to the fuel cell, which had an ATL sourced top fill panel. This is shown with the partial aluminum enclosure around the aluminum fuel cell can in the picture below.

Because of the unusual back seat fuel cell location the filler neck was added to the right rear window. A simple fuel filler neck and cap were sourced from ATL and added as shown below.

Ryan took some aluminum tubing and welded a mandrel bend at the top to line up the filler tube to the cap in the window. A short piece of flexible tubing was added at the bottom but this is only silicone and will be changed out for a fuel safe flexible hose soon.

To make this filler neck fire safe the entire fuel fill section was then wrapped within a metal enclosure.

This is what it takes to put a fuel cell in the back seat - lots of fabrication work. An upper section to the fuel cell enclosure was built to tie into the fuel filler neck enclosure tube-within-a-tube. Ample room in the top enclosure was added to allow for plumbing AN lines from the fuel cell to the fuel pump and engine and back, all of which will run under the car.

All of this can be unbolted in sections for service, but most importantly fuel can be easily added outside of the car and end up in the fuel cell - with fire safe enclosures around everything. That wraps up the fuel cell can, filler neck, and enclosure. We still need a fuel cell bladder, which we have been trying to get quoted for many weeks.


Since this car was missing the front end, we needed a new bumper cover and bumper beam. Early in the project the customer sent us a rendering of another BMW he liked and this 1M style front bumper cover from Duraflex matched closely with the later M4 race car he found. Duraflex is a branch of Extreme Dimensions and Carbon Creations. They make a lot of bumper covers, hoods, and fenders for late model cars in fiberglass or carbon fiber. They often have unusual style changes, like this one, which was the 1M look front end but made to fit an E46 M3.

We sourced this front end early in the project and mocked it onto the car, but now it was time to mount it properly and add a bumper beam. The Duraflex material is somewhat flexible and easy to work with or modify (mostly it works like fiberglass) and it is also cost effective. It might have worked with the composite M3 front bumper beam but those are still heavy and expensive, so a tubular beam was built using the same 1.75" DOM roll bar material used in the roll cage.

Ryan built this beam using the 3 wheeled tubing roller, then built standoffs that bolt to the factory location. There are no "bumper struts", just steel tubing. From this beam he added brackets to bolt dual Setrab oil coolers up front as well.

The twin coolers line up with the outer fog light openings in the 1M styled front bumper cover. The rear OEM bumper was replaced with a similar tubular 1.75" dia beam as well. I will show that in a future update.

There was some additional structure added to hold the bumper cover along the lower grill opening. I ordered E46 M3 headlights and corner lights online, I cannot remember where. Ryan taped up the fronts and installed those before I could grab pictures, but they are just stock replacements.


We are much farther along than this post shows but I am out space so I better wrap it up here.

Next time I can cover the installation of the carbon fiber hood, the HPR built 7.7L LS engine, T56 Magnum transmission, twin disc McLoed clutch, SFI bellhousing, ARE 4 stage dry sump oiling system, rear wing installation, seat mounting version 3.0, aluminum interior panels/floors, LS7 accessory drives, custom 1-7/8" long tube header construction, and more.

Thanks for reading!

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wow, I really used to detest the 1M bumper on anything other than a 1M, but in that pic you've put up here it actually looks good for the first time ever on an E46 M3! nice work fellas, enjoyable detailed reads when you post, keep em coming!

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Discussion Starter · #29 ·
Project Update for October 10th, 2017: Much has happened to the M3 V8 CSL project over the past two months. Last time we covered the widebody flare design and construction, fuel cell and dry sump tank mounting and enclosures, Lexan windows, and the custom front bumper beam and 1M style cover.

This time we will show the installation of the carbon fiber hood, the delivery and installation of the HPR built 7.7L engine. To that we bolted a T56 Magnum transmission, twin disc McLeod clutch, and an SFI bellhousing. Onto the new motor we attached an ARE 4 stage dry sump oiling system, a hybrid set of LS7/CTS-V front accessory drives, and then Ryan started building a custom set of 1-7/8" long tube headers. We also re-did the seat / floor mounting (version 3), built a bunch of aluminum interior panels/floors, and mounted a giant rear wing with custom uprights and end plates.

The engine bay also received a lot of attention. A custom radiator and fans were ordered, brackets were made for a "rolled forward" installation, then custom radiator hoses built. An MSD Atomic manifold and 102mm throttle body were installed - backwards - and a custom dual airbox / cowl induction intake system was then built, with plenum sections extending behind the firewall and under the dash. Continue below to see the behind-the-scenes construction of all of this and more.


The minimum weight we are allowed to run this car is fairly low in some series, and to get there we will have to eschew metal body panels for carbon fiber composites - where practical. Of course there are some exterior pieces that are very customized (flares) and it doesn't make sense to "go carbon" there just yet, but the hood, roof, and trunk panels are readily available so we went to AJ Hartman Aero for his motorsports level, lightweight, dry carbon hood to match the roof he supplied us earlier.

The first hood we received suffered some heavy shipping damage - but we purchased that one anyway, fixed it with some carbon fiber repair (shown in the 330 build thread here), and used it on my BMW 330 which I race in NASA Time Trials. With a little bodywork and paint by our friends at Heritage it will look better - hoping to paint this car over the winter break (which is only about 2 weeks long, here in Texas!)

For this M3 CSL V8 build we wanted to start with an unblemished hood, and the second one arrived (in a crate) with no issues. It looked perfect and was weighed in at an astounding 9.5 pounds! We don't have an accurate weight on an M3 hood, but the original steel hood from my E46 330 was 44.5 pounds.

I can only "one hand" this hood because it is so light, with no glossy gel coat. Many aftermarket "carbon" hoods are made by: start with a fiberglass main structure, then add a thin carbon fiber overlay, then a thick glossy coat of resin on top to make it shiny. These end up being MUCH heavier.

The low weight on this "real" dry carbon hood also comes from the fact that about two thirds of the under hood structure is omitted. AJ builds this hood with a second layer of formed carbon fiber underneath to support the OEM style hinges and some of the side structure along the length, but leaves the middle and forward sections without the ribbing. The hood is made of several layers of carbon weave. Using the OEM style hood releases is not possible - because this is a racing part.

The fenders needed adjustment to fit the hood - we bought this rolling chassis with no front sheet metal or hood installed. The OEM "J-clips" were gone so Ryan installed proper nutserts into the upper frame mounting sections. The original fenders from my blue 2001 330 were then tweaked to fit and squared to the front end, all fitted around the carbon hood (top left). One of the old hood hinges was very bent so a new one was ordered and installed (top right).

After some time re-hanging the fenders (plus slotting some fender mounting holes) and tweaking the hinges, the hood and fenders fit nearly perfectly. We'll let the body shop do the final body gaps perfect, but I'm pretty happy with how it all squared up. Its gonna be a shame to cut a bunch of holes in this hood!

Since the twin OEM hood lathes and secondary catch aren't used with this hood we will need to install some AeroCatch hood latches - similar to how this pair shown above went onto my 330 using the same hood. These have functioned great for months without issue on that car, and we have used AeroCatches on many race car builds. Ryan will reinforce the radiator support on the M3 for the two hood pins, just like he did on my 330.


This may seem excessive, to go back for a third time to modify the floor and seat mounts, but its pretty dang critical. We did this round of re-work gratis, as we just were not happy with how the floor structure turned out after lowering the seat. And frankly the seat was too low for the customer. There might be a taller driver that takes laps in this car, but the owner is the primary driver, so we build around him.

Cutting out all of the OEM seat reinforcements, the two "risers" that travel from the door sill to the tunnel, weakened the floor structure enough to allow flexing of the floor if we pushed hard enough at the top of the seat. Not good enough. The problem was we were trying to make the seat low enough so his head can NEVER come close to the upper door bars, as this car may be street driven at some Optima events on the "road rally" portion without a helmet. It is ALWAYS tricky to make a safe roll cage for a street driven car. In a dedicated race car it is assumed the driver will always have a helmet on.

So now instead of a tubular seat brace that bolts to the thin sheet metal floor, then the side brackets and/or slider bolt to that... Ryan has made this 3D structure of plate steel reinforcements that is similar in layout to the OEM stamped bits - but lower and thicker. The OMP side brackets now bolt to this reinforced structure, which is welded to the non-flat floor along the bottom seam. This new structure now takes up for the funky floor shape, is lower than the OEM reinforcements could allow, and much more rigid and strong than what we had in version 2.


We normally use the 1998-2002 Camaro LS1 front drive accessories on both our E36 and E46 LS swap kit installs, as these offer the most compact layout of power steering pump, alternator, and water pump without fouling the frame rails or inner fenders. These 4th gen drives do push the pulleys forward in the engine bay more than the Corvette C5/C6 drives, but less than the LS truck drives. For this build we knew we needed a dry sump pump and we wanted to roll the radiator, which could put the bottom of the radiator close to the engine. To make room forward we looked at the C5 and C6 accessory drives for this build, but the traditionally high mounted Corvette alternator would need to move. Plus the power steering pump would need to be deleted.


The above link from Nook and Tranny is a great resource for LS drive layouts.

You can see the factory C6 Corvette Z06's LS7 engine accessory drive setup above at left and the LS2 CTS-V drives at right. Note the very HIGH and WIDE mounted alternator, common on the C5/C6 Corvette setups. Plus the power steering pump placement for the C6 - which we don't need due to the electric EPAS steering we have added.

For this M3's accessory drive setup we used a hybrid assortment of parts: the water pump and upper tensioner/idler from a 2010-13 Corvette C6 LS7 and the low mounted alternator and idler pulleys from a CTS-V LS2. Ryan machined a custom spacer, used a threaded hole on the CTS-V alternator bracket, and added a second "smooth" idler pulley near the alternator - the lower one shown in the picture, above right. The Pontiac G8 alternator bracket we used on some other Ls swaps sits in a similar spot but uses different brackets. This second idler helps give enough "belt wrap" around the main balancer pulley for the unusual "power steering delete" belt routing.

We chose the later LS7 water pump, which moves the water neck closer to the driver's side - making a shorter hose run to the radiator. Since we had never done this custom accessory drive layout before, once the final engine was here (with the balancer installed by HPR) a bit of measuring and a couple of belts were tested before the final serpentine belt length was nailed down.

While the HPR shortblock was awaiting the CNC cylinder heads, we borrowed the ARE 4 stage dry sump pump temporarily - to make sure we had no interference with the accessory drive bits we planned to use. The dry sump pump fits in the spot where the A/C compressor mounts - low and to the passenger side of the engine.

So this hybrid accessory drive setup gives us the best of both worlds: a low mounted alternator (CTS-V) along with a short drive setup front to back (Corvette). This added room up front with this drive setup will come in handy when we mount the radiator (below). This also opened up the top of the engine bay, near where we will duct the hood later.


For an engine this big something larger than our production E46 LS Swap 1-3/4" primary long tube headers were part of the plan. We couldn't wait for the finished HPR 7.7L long block to arrive to begin the custom 1-7/8" primary header fabrication, so a mock-up engine and new accessory drive were installed for the early fab stages.

We were using bends, flanges, and collectors from a new supplier, and there were some... "issues outside of our control" that slowed delivery of the additional parts we needed to finish these for a few frustrating months.

There was also an extremely long delay waiting for a new set of ICE Engine Works modeling bends for this 1-7/8" primary size. After months of waiting we finally punted and used our 1-3/4" (orange) bends to simulate the layout of the tube for the larger tubing size. It slowed things by a bit but Ryan got through the driver's side header.

During one of the extended waits for more bends the custom steering column was completed with this firewall mounted steering shaft bearing. The somewhat large factory hole for the OEM column was closed up, then a new hole was drilled to fit the bolt pattern of the firewall bushing.

While he was working on the firewall, Ryan made a template (above left) then an aluminum panel with a 3D shape (above right) to cover holes in the firewall for the brake booster/master cylinder and a wiring harness. This panel was then covered in DEI reflective gold foil. With that area sorted out, the final section of the header on the driver's side could be built - if we only had supplies.

A couple of months later we finally had enough matching bends - and the driver's side header is complete. This past week Ryan was on the passenger side header, which will be wrapped up soon.

continued below

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Discussion Starter · #30 ·
continued from above


We ordered a 442" stroker engine for this project last year, before engine builder Erik Koeing moved to a new shop in McKinney, Texas. While instructing for at the School of Automotive Machinists (SAM Tech) he started his own engine shop 2 decades ago. Koeing and I have been friends for 30 years and another business owner friend of mine and I partnered with him to bring his shop to the Dallas area, which we relaunched as HorsePower-Research (HPR). He has been working with LS engines since they were introduced, and the standard deck aluminum block 468" is one of his popular creations. After he was setup in the new shop we changed the 442" build to a 468", changed the cylinder head choice to an LS7 style, and this pump gas fueled, naturally aspirated 7.7L beast was the result.

This engine started with a dry sleeved, aluminum OEM block with a 4.250" stroke and honed to a 4.185" bore. The forged crank uses HPR's propriety forged rods and pistons, coupled with some block clearancing, to make it all fit. Koenig has built dozens of these 468s for street, drag race and road racing applications - the biggest displacement anyone has safely built inside an OEM LS block.

The blueprinted shortblock was assembled with CNC ported, LS7 style cylinder heads made by Texas Speed. A high lift hydraulic roller camshaft was built to Koenig's specs for this pump gas, road course setup. A similar 468" was recently built for an Optima competitor and made 604 whp - with smaller heads, smaller cam, and smaller headers (described here). We're hoping to see 650 whp from this on 93 octane, with the intake manifold we have started with.

We were excited when the cylinder heads arrived and I could pick up the completed long block. I brought it to Vorshlag for final drivetrain assembly and installation into the M3.


To deal with 700 ft-lbs of torque we went went with the strongest commercially available 6 speed manual - the Tremec T56 Magnum. This Tremec is rated right at 700 ft-lbs of torque, which we will be testing with this engine.

This build has higher safety levels than most so an SFI rated scattershield was chosen instead of a cast aluminum bell housing. This unit from QuickTime bolts to the T56 Magnum and fits the LS engine. Well... "fits" is a loose term. ;)

For the clutch we went with a custom version of the Mag Force twin disc setup from McLeod, highly recommended by our transmission supplier. This has a unique Kevlar friction surface that should work well with the standing starts needed for Optima Speed/Stop and Autocross events and still handle the power this 7.7L can dish out on the road course.

Everything was assembled with care, checking torques and sequencing. Once everything was lined up the bell housing was aligned to the centerline of the crank by checking run out with a dial caliper. The twin disc clutch was aligned with a steel alignment tool and the transmission was installed... but it just would not line up.

The clutch, flywheel and bell housing were re-aligned and re-checked more than once. Turns out that aftermarket welded scatter shields sometimes don't exactly line up as perfectly as a cast piece that is CNC machined. Using some offset dowels in the block and this scatter shield alignment tool above the QuickTime unit was finally aligned.

The McLoed clutch slave/TOB was installed for the final time and the transmission went into the bell housing. The engine/trans was finally ready to go into the engine bay of this M3.

With the front nose and radiator support removed its easy to stick the engine and transmission assembly into the car. We used our production E46 LS swap kit motor mounts and transmission crossmember to line it up in the engine bay.

The dry sump pump was bolted on once the engine was in the car, to avoid smashing the shiny bits or fittings. The front drive accessories were already installed with the serpentine belt, then the cogged belt went onto the dry sump drive.


Spec'ing the radiator for this project took a little bit of work. This 7.7L motor would need the biggest radiator we could fit in front of the motor. We also wanted to duct the hood and "roll" the radiator forward at the top, so that meant we wouldn't be using an off-the-shelf aluminum E46 radiator.

I asked Ryan to clear away anything in the way between the frame rails then measure for the widest core we could squeeze in there (27"). The center portion of the lower stamped piece of the radiator support was completely cut out. He then built a cardboard mock-up to verify the max height core possible. Then we had to spec the hose outlets for an LS engine accessory layout, with the suction on the passenger side and water pump outlet on the driver's side. The goal was to shove as much of the radiator forward under the radiator support as possible without running into the front nose or crash beam. Unfortunately the headlights became a limiting factor for forward roll of the radiator, so the bottom of the core was pulled back closer to the balancer, to gain more angle and radiator height room.

The mock-ups and other specs led us to a BeCool 60229 radiator, which was custom ordered back in May. It took a while to be built and shipped here but when it arrived Ryan made brackets to mount it in the layout we wanted.

After the motor was installed with the balancer in place the BeCool unit was mocked-up in the final rolled forward position. Templates for brackets were cut and transferred to aluminum plate, which were cut, drilled and welded to the side tanks of the radiator.

The brackets were drilled for mounting holes that allowed them to bolt to the frame rail. Nutserts were drilled and installed into the frame rails for these mounting bolts, shown below. These initial mounts are bolted directly to the frame but about 1" of room was left to add some isolators. We will do this when we build the ducting, as well as possibly add a secondary set of mounts at the top and/or bottom.

More calculations were done and the slimmest, highest flowing pair of fans that covered the most area of the core were ordered.

These Mishimoto Slim 12" electric fans (MMFAN-12) each flow 1150 cfm. A bracket was built along the top and bottom to mount them close to the radiator core. There are more powerful fans in 12" but they were all thicker and could run into parts of the engine.

Some custom radiator hoses were built from HPS silicone hose bends and some mandrel bent and straight aluminum tubing. The front of the radiator core will be ducted to the gill openings at the front and to the hood opening behind it - we will show this later in the build.

continued below

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Discussion Starter · #31 · (Edited)
continued from above


After talking to Koenig at HPR at length about intake manifolds, he kept stressing how important it was to use the right design for larger displacement (7L+) engines. To keep the engine from peaking too early, and losing all of the top end power, a shorter intake runner length (6.5-7" long) with enough cross section and throttle body size would help. There are many manifolds that have MUCH shorter runners (which kills mid range completely and rarely helps on top in an NA motor) and all too many with OEM style, LONG runners (which shuts off the top end). Not many in the middle...

One of the few that have runner lengths and TB sizes in the range we wanted was the Holley Hi-Ram, which comes in cathedral, LS3 and LS7 style ports. With an optional 105mm throttle body opening and a 6.5" runner length (which is almost perfectly straight) the Hi-Ram could be worth another 30-50 whp up top. After I found the CAD print (top left) for this I asked Ryan to make a quick cardboard mock-up to check hood height. That was ridiculously too tall, and even flipped 180° to make it a "cowl breather" it was still many inches above the hood line (see above right). Like "making it hard to see" tall. We talked about making a custom intake but it was really time to "get going" so we picked the best OEM style intake on the market for the moment: the MSD Atomic.

Of the OEM style crossover intakes the MSD Atomic LS7 intake has the "least long" runners at 8.5". The 103mm throttle body size is a bit unusual, as the common "big" sizes are 102 and 105mm. Then a lot of those options are cable operated - old school. To work seamlessly with a Motorsports traction control system we went with a Nick Williams 102mm DBW (Drive By Wire) throttle body.

This manifold bolted onto the HPR motor without any drama, and with the TB opening pointed forward it fit under the hood easily. But we're not going to keep this build easy... we wanted to flip the intake manifold 180° to keep the front clear for hood ducting (which we will show in a future installment) and to take in high pressure air at the base of the windshield (cowl). This "little change" unleashed a lot of custom fabrication work....

First of all, the OEM cast aluminum intake valley cover has an oil pressure riser cast into the back of the motor. You can see the red colored tip of this riser in the image above left. Most LS style intakes have a recessed edge to clear this at the back of the manifold, which can be seen in the image above right.

So to be able to flip this intake around we needed a flat valley cover with this oil pressure sensor riser deleted. This flat billet cover from ICT fit the bill and was an easy fix. This was installed and let us run the MSD Atomic flipped 180°. But as you can see above, there was no room at the firewall for the throttle body. I was hoping the TB might line up with the massive opening left by the cabin air filter structure, but this intake is too low to line up with that. Time to cut...


To make this flipped intake fit we needed to cut the firewall up a little. Well.... OK, a lot.

This was the first stage of making a cowl induction intake system. You see with a mostly gutted dash and aftermarket HVAC box mounted elsewhere, and relocated master cylinder and no brake booster, all of a sudden we had a lot more real estate under the dash and at the firewall. So Jason, Ryan and I brain stormed an airbox mounted at the base of the windshield with a flat air filter element. Or two.

To maximize airbox volume we wanted to use a flat element air filter. Due to some space constraints in area, as well as off-the-shelf filter elements and their associated airflow limitations, we needed TWO air filter boxes. So we ordered those up while Ryan started building a plenum at the throttle body.

This box above will attach to the 102mm throttle body and create a certain amount of plenum volume for the engine to draw from. Air will enter through each of the 3" oval openings from the two air boxes. The constraints of the hood and engine placement limited the intakes to these 3" oval sizes.

The 4" opening to the throttle body has a formed bell mouth and the box itself sits up under the dash. Ryan will make another fire proof enclosure to completely surround this and seal the engine compartment away from the passenger cabin/dash area (see below/left)

Twin air filter boxes were built, one for each side of the engine bay. They are somewhat mirror images but they do have some differences side to side, which are underneath.

These air filter boxes mount to the chassis and then 3" tube and 3" silicone hose couplers route the "cold air" to the throttle body plenum box. Two K&N filters fit snugly into the tops of these air boxes and we will add some additional structure and seals that touch the bottom of the hood soon. These will mate up with two big holes we will cut in the hood to feed these filters.

A couple of dozen hours went into the firewall clearancing, layout, plenum box fab and two air box fab work, but it should be more than able to supply this air to engine. This is being fed by a high pressure zone at the base of the windshield, which will help "at speed". And it all will help the Optima Design & Engineering scoring, too. Again, this is really being done to open up the front of the engine bay for hood ducting, to improve downforce on the splitter (soon) and improve cooling on the main radiator.


Up to this point we haven't shown much of the interior or our plans to make it safe yet pleasing to the eye. Gotta pass muster for D&E - they really punish gutted race cars in Optima, unless some real attempts at "an alternative interior" are made. Initially we just had roll up windows and custom door panels, but the rest was pretty Spartan. All business, no frills, and somewhat ugly. Time to spruce it up in there...

This interior was largely gutted when we found it, along with the air bags. The stock HVAC is also too heavy for a build like this, but we did add a compact heater core and blower motor unit that we've used on a number of race cars (just like on the tube frame 69 Camaro build). This 7 pound unit from Summit Racing is cost effective, compact, and much lighter than the OEM parts. This box was mounted under the dash on the passenger side and the outlets will be plumbed to the defroster vents soon. No air conditioning is going to be added - too heavy, and there is no place to drive an AC compressor with a 4 stage dry sump pump in the way.

Another Tilton triple reservoir was purchased (also like on the 69 Camaro), which will feed the twin brake and single clutch master cylinder from the OBP floor mounted pedal box. This Tilton unit was mocked up and then mounted on the passenger side. Why have this in the passenger compartment? Three reasons. 1) Being visible to the driver makes it easy to see if fluid LEVELS drop during a session (indicates pad wear or a leak). 2) It makes it easy to fill the fluid levels, not buried down by the floor mounted pedals. 3) It keeps the bulk of the fluid away from heat in the engine bay.

A few weeks later Ryan went back and made -4 AN braided lines for the reservoir and ran them to each master cylinder.

The spot your heel rests on at OBP pedal box was tied into a flat, false floor made of aluminum. A formed sheet aluminum dead pedal was also built and tied into the same section. These false floors are commonplace in race cars, and with the unusual non-flat floors of the BMW E46 they are pretty much a requirement if you remove the carpet and massive foam backing.

These were formed from 6061 sheet then dimple die holes were added on the press. We will add grip tape to the surfaces later, to keep your feet from sliding around if they get wet. The passenger side false floor was started but still needs some dimple die work.

We couldn't leave the stock steering wheel in place so we ordered a Sparco wheel and Lifeline quick disconnect hub. This wheel fit the driver's position and has the right covering, and the Lifeline is the best quick disconnect on the market.

Window nets might seem a bit extreme for a car with roll up windows, and it is unusual. But for a "street car" this M3 has an unusually high speed threshold, so the safety gear isn't being skimped anywhere. This mesh window net has great visibility but keeps "your arms and hands inside the ride at all times". We will add a center net later as well.

A lot of aluminum panels were built, which help fill holes in the dash where the radio, HVAC controls, and stock gauge cluster went. An AiM digital dash, possibly a rear view camera/LCD screen, and the fire pulls and main battery kill will go back into these places. A new set of "Titanium" OEM trim panels was ordered from BMW and installed to fill the gaps between the 2-pieces in the upper and lower dash sections. We will get a little crazier with interior panels and finishes before the car ever does an Optima event, but its already a lot better than the plain "gutted race car" look.

continued below

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Discussion Starter · #32 · (Edited)
continued from above


"Big Downforce" is part of the "Bigger is Better" mentality we are applying to many aspects of this build. Of course a giant rear wing was ordered from AJ Hartman Aero - a full 72" wide and with his longest 14" cord.

We have installed plenty of rear wings but on a car that could see speeds in excess of 180 mph, it needed to be a bit overbuilt.

After deciding where the uprights would be (and thus the under-mount saddles) we ordered the wing. When it was delivered we played with mounting locations, getting the element where it could "do the most work" - way up high and far back - then Ryan made cardboard mock-ups, which progressed into plate aluminum versions. We had thought about a bent upright, but that was quickly abandoned in mock-up.

We settled on this flat design that would be gripped with a steel U-shaped lower bracket, that could then be bolted to the trunk.

Once these were cut, brackets made, and they were test fit the lower steel brackets were bolted to the trunk lid. The OEM steel trunk lid is very strong but we also extended the lower portion down to touch an adjustable perch onto the tubular rear bumper beam. We will made a "saddle" that looks prettier before paint, but this puts much of the vertical load into this beam and less on the trunk structure.

The trunk can swing open fully and the wing element clears the roof easily. This is due to the rear biased, high mounted placement of the wing element.

The "windows" above were cut out by hand - using a hole saw and jig saw. There are much faster ways to do this using robots... a CNC water jet or plasma table makes this much faster but we didn't have the time to transfer all of this into CAD then run use someone's table. Yes, I need to buy the shop a CNC plasma table...

The lightened uprights were completed and then endplate designs were tested and tweaked...

Some details on the image above (red line) have been completed but its the best picture I have of the finish wing currently.

GTL class - any spoiler or wing configuration with a maximum of 6***8221; tall from its highest mounting point or a maximum height of 4***8221; above the lowest point of the rear window, whichever is less. The maximum width of the spoiler/wing must be no wider than the original panels of the car and must not extend more than 6 inches past the furthest point of the rear of the car. No wing may exceed 8 inches in chord length (front to back) at any point.
We know that the 2017 aero rules for Optima are pretty limited and we will create a separate aero package for that series. We will use a carbon fiber trunk to mount that Optima aero package, which would make for a simple "trunk swap" to be legal for that series. The big wing would be used in NASA and other events.

A massive splitter, the soon-to-be ducted hood, and some other bits will make up the front aero. We just made this front splitter for my 330, but the one for the M3 will be bigger in every way.


Wow, that was a lot of ground to cover, and I didn't get to everything that's completed. Next time I will show the twin fire systems, chassis wiring that has begun, the fuel system components that have been arriving, and the Motec M1 + wiring harness which is being built by our friends at G-Speed.

The rear differential is now assembled with a Wavetrac LSD and Ford Racing gears, the exhaust headers should be wrapped up soon, and then a driveshaft and exhaust can be built after that is in place. The custom coolant reservoir was just completed, heater hose plumbing has begun, and Ryan is spec'ing out the oil hoses next.

This is what the M3 looks like today. Tune in next time to see more progress!

Thanks for reading,

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holy crap so this is what lottery winners get to do to cars i can but dream,, the time frame though gives me hope for my driveway 330 project actually being done at some point,, amazing work cant wait to see this thing moving

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181 Posts
Discussion Starter · #34 ·
Project Update for January 23rd, 2017: Vorshlag got super busy over the past 3 months, so I am behind on build thread updates, but this project has been moving steadily along. Ryan has been plugging away on this M3 for 3 out of every 4 weeks since, and there is a lot to show here: Two fire systems, the custom headers finished, the 8.8" diff built and installed, fuel injectors and lines installed, oil lines build, chassis wiring, coolant reservoir + plumbing, battery kill, coils and plug wires, fuel cell installed, driveshaft built, interior panels, and brake inlets, whew!

I am going to speed up a bit and show fewer pictures for each task, unless it is super unique or interesting. Let's catch up this build in what is probably our last update before we fire the engine up!


Normally we would tell E46 guys to just use the 210mm "large case" diff unit from the E46 M3, which can probably handle 600 ft-lbs of torque. As I mentioned before we wanted to build an aluminum 8.8" ring gear IRS housing strong enough to deal with 700 ft-lbs of torque. This Ford sourced unit is lighter, stronger, and has more cost effective options for gearing and differentials than anything ever offered by BMW.

This unit uses the custom steel rear cover shown in previous updates which bolts into the E46 M3 rear subframe. The front of the subframe was modified to use the two forward bushing mounts on the front of the Ford unit, with aluminum bushings we machined in-house.

We chose the Wavetrac 31 spline 8.8" differential for this project. Wavetrac's torque biasing design is the only Torsion style differential made to work in no- or near no-load conditions (if a tire is lifted). The helical 9310 steel gears run in case-hardened billet steel case built with ARP fasteners. They are maintenance free and should perform a lifetime of service without maintenance or rebuilds (has a transferable, Limited Lifetime Warranty). We told them what we had in mind - a life of torque pushing 700 ft-lbs through 345mm Hoosiers - and they said "no problem", so we set up Vorshlag as a Wavetrac dealer.

Several calculations were made to come up with a final gear ratio of 3.73:1, and of course we only use Ford Racing ring and pinion parts + Ford bearings. These were assembled into the freshly bead blasted and then thoroughly cleaned aluminum 8.8" Ford IRS housing.

A "set-up" bearing was installed on the pinion with a pre-crushed sleeve to shim and setup the ring and pinion depth, until Aaron saw the right pattern.

The side bearings were installed and shimmed with zero pre-load on the housing to get back-lash within range. Then Aaron built this tool to spread the aluminum housing...

This spreader tool allowed him to then add .006" of pre-load on the side bearings for proper installation on the aluminum housing. There are some tricks to setting up the aluminum 8.8" IRS housing correctly...

The side axle seals were added and the unit was installed into the chassis.

I will end this section with the shot above, showing the 8.8" housing, SPL Parts lateral arms with sphericals, and big fattie 345mm Hoosiers. This setup should be able to handle all the torque the 7.7L engine can throw at it.


When we designed our LS swap kit for the E46 chassis we built it around the still somewhat common 1998-2002 F-Body Tremec T56. This OEM trans was rated at 400 ft-lbs of torque, which was OK when LS motors made 300-350 hp.

For this car we went straight to the T56 Magnum - which shares almost nothing with the OEM T56. The Magnum has 700 ft-lbs of torque rating, but the shifter is about 1.5" farther forward. The shifter that comes with the Magnum is shown sitting atop the tunnel in the pic above right. We used an SFI rated scattershield from QuickTime as well. Safety is important on this build.

The stock round shifter opening is pretty far back relative to the Magnum's shifter placement, so Ryan cut out the tunnel to expose the opening for this trans, then made an aluminum plate to cover it all up. To this he mounted the aluminum base for the Joe's Racing shift boot attached (see above at left). This includes a heat shielded Nomex shift boot (just sitting over the console opening, above at right) which snaps in place to the provided aluminum base, making for a fire / fume / heat barrier between the underside of the trans tunnel to the cabin. We use these Joe's shift boots on everything.

The Joe's Racing boot will hide under the OEM center console plastics (which are shown above without the boot) and underneath a second, OEM shift boot. The included Tremec shifter put the lever a bit too far forward to be able to re-use the factory center console. For a race car its no big deal but this car has to "look right" for Optima, so we ordered a McLeod offset shifter to fit the Magnum. This custom built unit has 1" right and 3" rear offsets. The images above show the McLeod shifter in place - notice the handle stub lines up with the old "round" shift hole opening. We've used these shifters on previous builds like this when the shifter doesn't line up with some OEM console pieces.

Once the McLeod shifter was in place a simple Hurst handle and 6-speed patterned black knob were added, then an OEM E46 M3 BMW Alcantara shift boot snapped into the OEM center console from above. This is the "pretty" shift boot to cover up the race parts underneath.

That's the finalized shifter sitting in the OEM center console, above. Took a bit of work to get it all to line up but the shift feel is great and the McLeod unit has adjustable shift stops to prevent over-engagement. If the shift lever length isn't comfortable for the owner we will buy or make another arm, and the same goes for the knob.


The MSD Atomic intake manifold is one ugly cuss of a cast Nylon unit, bit it outflows the other "OEM height" intakes for big displacement LS engines (including the FAST), and it will fit under the stock height hood. One other oddity is that the shape does not clear any aftermarket fuel rails. From anyone. We wouldn't consider using an OEM fuel rail on a build like this - both from a performance and aesthetics stand point. the OEM fuel system is made for a return-less style routing, which is another "Hard Pass".

After wasting a good bit of time reaching out to companies who sell custom fuel rails (none of which had tackled the MSD yet) we settled on the same Holley extruded rails we use on a lot of LS builds. Ryan marked them for clearance around the various lumps and bumps in the MSD Atomic and handed them to Tim, who chucked these up in our CNC mill and got to work...

Instead of mapping the cut-outs and programming the job in CAM software, then cutting each rail in CNC mode, Tim used the Digital Read Out and manually moved the cutter to clear away metal where Ryan marked. Each rail was milled in an area that isn't critical for strength or fluid / pressure containment, as shown above. It was a bit of a pain but with an end mill with a DRO you could do the same in about an hour.

The images above show the rails mocked up with some injectors, which puts the rails at their final height. Ryan then built custom brackets to attach the rails to threaded bossed in the intake manifold at those heights. The top right pic shows clearance around some of the weirdly shaped humps in the MSD Atomic. Now about those injectors...

The tuner we are working with to build the Motec M150 ECU and engine harness wanted us to use the Bosch Motorsports based Injector Dynamics set. But at $1000/set it was making my eye twitch! Even if it is not my money, I still try to look out for our client's budget. We investigated some other brands, made some calls, and then I went with DeatschWerks. Their 16U-00-0065-8 injectors flow 65 lb/hr (700 cc @ 3 bar), have an EV14 plug, LS3/LS7 injector height, and also use Bosch Motorsports parts. They cost about half as much as the IDs but are built with the same housings and coils. I liked them so much we became a dealer and you will see more of these on our other builds, like my C6 Z06 (aka: #Rampage).

Of course there is a frenzy that stirs up around certain sacred items and beloved brands, and when you ask "what injectors should I use" online it damn near breaks the internet. DW has the same Motec flow data for the tuner to use for EFI tuning, and if they work, they work. I don't get the hate, but I suppose I do the same thing around certain shock brands, so what can I say? #KoniTriggered

Before the MSD Atomic intake was final installed the hole for the MAP sensor had to be drilled. There are a couple of optional locations cast into the upper housing for this sensor (even the old LS1 EGR location), with a threaded boss for each. Ryan picked the one at the "back" of the intake, which will be at the front of this engine bay, and fitted the sensor in place.

This MAP sensor location will connect to the Motec harness being built for this car.


Not a lot of high tech here. Seriously, there's no need to spend thousands on coils or plug wires for any LS or LT V8. Just use good, proven brands that fit your engine's specifics. This ignition system is light years ahead of what the OEMs used even in the early 1990s.

When it came to coils I wasn't sure it was even worth using something other than stock replacement units (of which there are 5 distinctly different styles for LS engines), which can be bought for as little as $30/each. With EIGHT coils - one for each plug - there isn't a lot of stress on the ignition coil. These have a long time to saturate with high voltage before it fires it's one spark plug every two rotations. For this build I went a little further and bought MSD branded replacement coils, which were not that much more. We need D&E points for Optima, and "favorably branded" parts don't hurt.

We have had really good experiences with Holley Group parts, and MSD is a part of that. Naturally we went with Holley valve covers, too (polished aluminum units slightly taller than stock). These have integral mounts for one of the LS coil shapes, so we don't have to use the ugly black steel coil mounting brackets made for OEM valve covers. This engine bay needed a little bling.

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I had spec'd Holley valve covers out for another BMW LS swap a year earlier, but they didn't fit the E36 chassis they were going into. They went back in their box until we needed them for this E46 build - which has a 2" wider engine bay than the E36. We also picked up Taylor 409 series 10.9 mm plug wires and DEI heat sleeves.

The Taylor plug wires come in a variety of boot angles and colors, as do the DEI sleeves, but for this build we went with all black. The NGK plugs are now connected to the coils, which are mounted to the Holley valve covers for a nice, tidy look.


I never trust the itty bitty plastic reservoirs on BMW E46 coolant systems (I've had two fail on track in two different 330s!), but instead I like to see a larger, remote mounted reservoir set high in the engine bay with as much volume as possible. Usually that means at the back of the engine bay, opposite the brake master cylinder, which is the highest part of the engine compartment. That corner usually has plenty of room.

On this build of course we have one of the twin air filter boxes taking up that space, so I asked Ryan to utilize the space in the right front corner of the engine bay. He whipped up this custom reservoir out of cardboard mock-ups and turned it into an aluminum welded tank.

If you look closely at the image above left you can see that it ties into some OEM bracketry in that corner, for a bolt-in application.

Once we were happy with the shape and placement a few more items were ordered, including an aluminum weld-on radiator filler neck and some steam vent ports from TFS (made for AN lines). A number of aluminum weld-on AN bungs were also procured for lines that connect to the reservoir.

You can see the finished reservoir above, with the filler neck and welded bungs for AN lines. We used a 16 psi, lever-style pressure release cap. If this cap isn't deemed pretty enough for D&E, we will find some billet doo-dad with some shiny colors.

The various coolant lines were later built to connect to the reservoir, steam lines, and heater core hoses to the Motorsports defroster mounted under the dash. I will show this in more detail later, but the cooling system is plumbed.


One thing virtually all race cars are required to have is a main battery kill. If you see the "magic smoke" being released from your car's wiring (it only comes out once!) or if you have any type of racing crash / incident / fire, you are supposed to hit that button first! But gone are the days of the $25 electro-mechanical kill switches, which have a high failure rate and require high amp cables to be strung near the driver's switch. Even the solenoid relay style kill switches still have moving parts that can fail. Now there is something better.

The solid state electronic "battery isolator" units from CAR TEK out of the UK are a slick, safe, and FIA approved solution. This page shows the evolution of the kill switch. We saw how much US suppliers were marking these up so we purchased a bunch of these and became a dealer. We have used them in the past and will be putting these on everything...

There are two main models from CARTEK. The "GT" model shown above kills the engine by taking in a fixed 12v input and sending a 12v output that would power your Ignition or ECU. When the negative side of the battery has been disconnected it will also cut the 12v output powering your Ignition or ECU. This will kill the engine. Designed for cars with Standard ECU’s or Historic Race cars. These can be wired with one or two remote kill switches, which have integral LED lights inside the button.

The "XR" unit we chose for this build is made to trigger a Motorsports ECU (like the Motec M150 we are using) or PDU. The "XR" unit is newer and does not have a power input or power output. Instead it sends a signal which is wired to either a Power Distribution Module or Motorsport ECU that has an ignition switch signal input. The ECU or PDU will then shut down when it sees this signal - which then kills the engine. The XR also features a 0.5 sec time delay between transmitting the engine kill signal and disconnecting the battery, allowing the ECU time to perform a shutdown sequence before electrical power is lost.

It was a relatively easy hookup, with the XR unit placed in the trunk area on a panel Ryan built near the Odyssey PC80 battery. Two kill switches were added with one mounted on the dash and the other out the driver's side window area, so a corner worker could disable the power if the driver was incapacitated.


This car is being built with serious safety in mind, to match the serious performance it will be capable of. To take it to the next level we built this car with two separate fire systems. And each system has two cables - for multiple locations.

One Aqueous Foam (AFF) fire suppression system is plumbed for the engine bay, where most of the fire situations break out on a race car. If there is evidence of smoke from underhood and the driver has the right mindset and training he can pull that release handle (only) and snuff out the fire without filling the passenger compartment with foam.

If something is on fire in the cabin the driver can grab that handle - or both - as he is bailing out. We have dual pulls for each bottle, too... with a pair for each system on the center of the dash (driver) and a pair outside the driver's window (corner worker, or driver after he bails out!)

These were cabled with the included cables that came with each fire system from Lifeline. The secondary cables were purchased from a local bike shop and added to each pull handle on the bottles. Each pull will be marked clearly and boldly, but if in doubt - pull 'em both! I will cover these again when they are plumbed to show the nozzle detail in my next post.


One more safety aspect is finally wrapped up, and boy this one was a major task! You saw the creation of the fuel cell enclosure and then the firewall structure around that, but when we sent the drawing off to be quoted by "the companies everyone uses" we had a heart attack with their quotes.

A few years ago we found Harmon Fuel Cells. They had some BMW cells that we thought we could use in our standard swap cars, but this one was going to be custom. So we sent them the drawings and enclosure to quote. Their ballistic kevlar FIA approved fuel cell with an integral surge tank and twin Walbro 450 pumps was HALF the cost of the "name brand" fuel cell. This was an eye opener!

The reasons we got for the high quote were "time and materials" to make the custom cell, but Harmon seemed to use the same materials and got it done for less, with all of the right FIA markings. I'm now a fan of this brand, especially for custom cells. The twin pump sump looks good and should keep this engine fed with fuel down to the last drop.

The fuel cell is now mounted in the car's back seat, the lower section of the firewall enclosure is mounted, and Ryan is plumbing the fuel system from the cell to the engine bay.

The AN braided lines switch to aluminum tubing under the car, to protect them from fire / cutting / off road adventures. The feed line is a -8 and the return is -6.

Most of the fuel system is completed when I write this in January, with just a few items left to plumb this week.

One of the craziest parts of the fuel system is this Injector Dynamics F750 fuel filter with optional pressure and temperature sender. It has pressure differential meter on board, drain, integral mount, it is all made from 100% CNC machined aluminum. The point that really matters: it has a replaceable filter element.

This was something G-SPEED insisted on for use with the Motec and cost a staggering $550. For a fuel filter. But these sensors are what they wanted for pressure and temp signals, so on it went. When you see it fist hand, the fitted foam box and the jewel like fit and finish, you can see where the cost comes in.


The OEM rear disc brakes on most modern cars use an integral drum brake inside the "hat" of the 1-piece cast iron rotor. The drum is actuated by the parking brake lever and locks the wheel when parked.

Well the Powerbrake 350mm 4piston rear brake uses a 2-piece rotor with an aluminum hat. Like the Stoptech Trophy and almost all other Motorsports brake kits they do not have a provision for a parking brake. But for Optima use this car needs one. We did some research...

We found that obp Motorsport out of the UK makes a hydraulic, stand-alone parking brake handle, mostly used in the drifting world. These also have a lockable setting for use as a hydraulic parking brake. I ordered the one Ryan spec'd and ... they shipped the wrong style, above, which is made for drifting. So now I own that one.

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I re-ordered the same part number and the second time they sent the right style, which can be configured to allow the handle to lie flat - like the stock unit. Stop the car, pull up the handle, engage the lock, and you have locked the rear brakes for parking.

Ryan built a bracket, mounted the E46 "console delete" center console, built a cover for the cup holders, and it covers the obp handle nicely. We will show the plumbing of this in a future post.


These custom headers should have been done months earlier but we had a series of delays on parts, tools, and equipment that is too long to list.

After the ICE Engine Works 1-7/8" header modeling kit arrived in November and then the Argon flow meter regulator arrived in December the last few bends could be finished.

Then each tube could be sealed off, back purged with Argon, and fully seam welded. Once each tube was leak free it was then welded into the flanges and collectors.

Ryan even installed the "cones" inside the merge collectors, for that last little bit of flow. The headers were quickly installed shortly after being final welded, so I didn't get the "glamor shots" they deserved. But no matter - they are done!


We measured for a custom driveshaft to fit this E46 with a T56 Magnum and the 8.8" diff housing. When we went to install it, we found we had left the factory brackets for the 2-piece BMW propshaft's center bearing and they were in the way of the fat 3" diameter aluminum driveshaft.

A little spot weld drilling and some cutting removed the offending brackets, which we didn't need in any case. Much bigger diameter driveshaft stuffed up as high as possible to give exhaust clearance in this tunnel.

With the newly acquired input flange for the pinion added (per our driveshaft company's recommendation for the torque this unit will see) the driveshaft was bolted in place. One step closer to moving under its own power.


With an external, 4-stage dry sump oil pump, remote oil tank, twin oil coolers, and a breather tank this car will need a lot of oil lines run over the course of weeks. Since we are already a dealer for Fragola, and to save some time, we did not farm this plumbing work out like we sometimes do.

Ryan designed an oil system routing and made us a parts list, then we ordered a boat load of AN fittings, hoses ends, and hose. After various components were mounted the hoses were built one by one, tested, and installed.

Instead of boring you with a lot of step by step pictures of hoses being made, let's move on.


Speaking of exciting, let's look at a bunch of pictures of custom chassis wiring! I have dozens!

I'm kidding, of course. Not many people like working on automotive wiring, much less building it, or watching it being built. But we do have a lot of pictures of this progress to show the customer as this work stretched out for a bit.

But seriously though, the work done in this area by Ryan was over the top. What started with a Painless 26 circuit harness has turned into a work of art.

The main wiring panel was built onto a false floor aluminum panel in the passenger foot well. All of this is hidden under another panel, shown above right, for a clean look - and to keep feet away from wires and components.

Lots of components are hidden under the dash or elsewhere and everything is noted in detailed wiring diagrams, kept within a binder. We are using Deutsch Connectors and pins for every connection, except for a handful of OEM connectors. Ryan was ringing out circuits today, bumping windows and lights with a tester, and the chassis wiring is almost complete.


The front end on this car was made from a hybrid 1M / E46 bumper cover made by Duraflex in a fiberglass-like composite.

Some might not like the look now but once the front wheel fairings are built and the splitter installed I think it will make more sense. It fit the look the owner was going for, but didn't really have a great location for front brake inlets.

Early on in the project Jason worked with Ryan when he was mounting the bumper cover to show him where we wanted to pull brake cooling air from - a high pressure section of the lower grill area. The two outer openings were then utilized for twin oil coolers, as shown above left. The brake ducts were recently built and fitted to the triangular sections shown above right.

Sometimes you get lucky and the OEMs make a nice, tapered funnel that necks down to a 3" or 4" round section you can slip a brake cooling hose over, but not this time. We decided on 4" cooling to deal with the speeds and brake heat load this car should be capable of. Ryan made the outer panel then transitioned this to a 4" round aluminum tube for the hose to fit over.

He makes it look easy but there was some time and skill that went into these inlets. We will add the 4" hose after the final oil plumbing is completed, but room was left to clear all of that and for the route to the front wheels. The brake backing plates were made months earlier.


Whew, that was longer than I thought it would be! What's next? Well last week Corey and Louis from G-SPEED stopped by to measure the engine bay for their custom Motorsports engine harness they are building to fit a Motec M150 ECU.

With this mapped out they are building the harness now for delivery soon. The last bits of plumbing and chassis wiring will be tidied up and then Ryan will move to the front splitter, wheel fairings, and rear diffuser.

And the exhaust system is already being built as well. Gonna sound good, and will exit through the diffuser.

More soon!
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