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!
FORD 8.8" DIFFERENTIAL HOUSING BUILD & INSTALLED
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.
OFFSET SHIFTER, SHIFT BOOT, HANDLE & KNOB
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.
FUEL RAILS BUILT & INJECTORS INSTALLED, MSD MODIFIED
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.
VALVE COVERS, COILS AND PLUG WIRES
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.