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Discussion Starter #1
I'm either looking for a list of some kind or way to make extreme power without asking for a death wish on my car. I bought it for 700 bucks and don't wanna go too crazy on upgrades as of right now since i'm still in school. any help would be greatly appreciated!
 

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2003 330cic, 2003 325iT
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RACP (rear axle carrier panel) is the rear body panel to which the rear subframe is attached. It was a defect in these cars and there would be tears around the studs. Look up subframe reinforcement to educate yourself.

I think that Spannerhead was pointing out that it is not a strong part of the car, and if you start jacking up the power you will likely cause it to fail.

 

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'02 330i 5-Speed
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Rear Axle Carrier Panel. It's the part of the unibody the rear subframe (that holds the diff) attaches to. BMW designed the E46 with a design flaw that causes the RACP to crack where the subframe attaches. In extreme cases, the whole subframe can detach from the rest of the unibody. Early E46s, like 323s and 328s, are particularly vulnerable. BMW quietly reinforced the area around the end of the 2001 model year but didn't fully eliminate the problem. Google "E46 subframe."

Given that the RACP is an issue at stock power levels, obviously adding any power at all is going to make it worse. Want to do the job right? Here's a DIY:

 

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Discussion Starter #7
Rear Axle Carrier Panel. It's the part of the unibody the rear subframe (that holds the diff) attaches to. BMW designed the E46 with a design flaw that causes the RACP to crack where the subframe attaches. In extreme cases, the whole subframe can detach from the rest of the unibody. Early E46s, like 323s and 328s, are particularly vulnerable. BMW quietly reinforced the area around the end of the 2001 model year but didn't fully eliminate the problem. Google "E46 subframe."

Given that the RACP is an issue at stock power levels, obviously adding any power at all is going to make it worse. Want to do the job right? Here's a DIY:

Thank you for that, I’ll check it out guys. I had always heard it as a rear subframe issue, but never knew the real issue. I’ve checked mine out and it’s alright. No cracks no where at 170k miles. But I know I have to do it at some point. So might as well start now!
 

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BMW 320i 2002 e46 5spd manual RHD
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Apologies for veering off thread, but was racp issues a problem on the 325i wagon aswell?
 

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Discussion Starter #9
Apologies for veering off thread, but was racp issues a problem on the 325i wagon aswell?
I know for the sedan and coupes but I’ve never seen anything on that though. I would do more research if I were you. Look videos like wagon e46 subframe reinforcements and see if anything pops up
 

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2003 330cic, 2003 325iT
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Apologies for veering off thread, but was racp issues a problem on the 325i wagon aswell?
This is one of those questions without a clear answer.

The highest risk was early e46s, notably 323 and 328 coupes. There were definitely cases of sedans, but few stories of convertibles and tourings.

This could be because they have different reinforcement because of their different structural oddities (no roof structure for the vert and no back seat cross-bracing for the wagon) or because there just aren't as many of them.

It is recommended when folks do s54 swaps to reinforce the racp in tourings.
 

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BMW 320i 2002 e46 5spd manual RHD
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This is one of those questions without a clear answer.

The highest risk was early e46s, notably 323 and 328 coupes. There were definitely cases of sedans, but few stories of convertibles and tourings.

This could be because they have different reinforcement because of their different structural oddities (no roof structure for the vert and no back seat cross-bracing for the wagon) or because there just aren't as many of them.

It is recommended when folks do s54 swaps to reinforce the racp in tourings.
That does make sense, i have a planned (future) project with either 318i or 325i touring body and slapping in the 330D, with an auto and diff...since getting a 330D touring is technically impossible here...but this is just a dream project for far in the future...but i guess if i do end up doing it...i.will just weild in some support if im down there anyway...
 

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2005 325i Auto
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832 Posts
Well my budget would be 3-4 thousand over the next year
If that's the case, why not just go with the intake/cooling refresh along with a Vanos and Disa overhaul. Getting your injectors professionally serviced (which is quite cheap) along with new air/fuel filters is well worth it too.

If you've bought this car cheap, it will most likely need these things, and the power increase will be very apparent when you've got it running right. No use banging headers or whatever onto a car that's not running correctly.

Then you can get your diagnostic tools like INPA, OBDfusion, etc and post your logs up here so the members can help you diagnose your fuel trims etc. There's so much to learn there, and it's an excellent challenge for new players (like myself). When your motor is all dialed in you may well be very surprised how much extra power you can get from a stock motor, I certainly was and mine's still a bit off in the fuel trims.

It seems the RACP issue is widely reported, but not so much from people who've had it happen. I wonder if making sure all the subframe bushes were good might help prevent clunking that leads to cracking. I'd be inclined to pull it all out, and if there are no cracks assume it's all good and reassemble with new bushes.

Before you do any of this though, it might be worth testing the motor itself thoroughly with a compression test, leak down test and block sniffer test, just to make sure you don't have blown head gasket etc. I'd certainly do that plus read all the codes before I spent a penny on it.

Hope that helps.
 

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2003 330cic, 2003 325iT
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Intake refresh - see my sig below is an easy win to familiarize yourself with the engine and minimize bad running.

Suspension refresh is a great performance mod for an older e46, and shifter bushings. Instantly tightens everything up!
 

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2003 M3 6MT Slicktop
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Cracking rear subframe floors and strut towers. This will happen on any E46 when you are looking to make that kind of power. Consider it a design flaw and find a way to increase rigidity to those areas.

You have been advised
 

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Discussion Starter #16
If that's the case, why not just go with the intake/cooling refresh along with a Vanos and Disa overhaul. Getting your injectors professionally serviced (which is quite cheap) along with new air/fuel filters is well worth it too.

If you've bought this car cheap, it will most likely need these things, and the power increase will be very apparent when you've got it running right. No use banging headers or whatever onto a car that's not running correctly.

Then you can get your diagnostic tools like INPA, OBDfusion, etc and post your logs up here so the members can help you diagnose your fuel trims etc. There's so much to learn there, and it's an excellent challenge for new players (like myself). When your motor is all dialed in you may well be very surprised how much extra power you can get from a stock motor, I certainly was and mine's still a bit off in the fuel trims.

It seems the RACP issue is widely reported, but not so much from people who've had it happen. I wonder if making sure all the subframe bushes were good might help prevent clunking that leads to cracking. I'd be inclined to pull it all out, and if there are no cracks assume it's all good and reassemble with new bushes.

Before you do any of this though, it might be worth testing the motor itself thoroughly with a compression test, leak down test and block sniffer test, just to make sure you don't have blown head gasket etc. I'd certainly do that plus read all the codes before I spent a penny on it.

Hope that helps.
My man... you are absolutely the best. You just gave me so many things to go into and check before anything. Thank you so very much azadani. I’ll finish with some of the maintenance this week and then check all of those things out. I’m screenshotting what you said just to make sure everything is fine
 

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2005 325i Auto
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My man... you are absolutely the best. You just gave me so many things to go into and check before anything. Thank you so very much azadani. I’ll finish with some of the maintenance this week and then check all of those things out. I’m screenshotting what you said just to make sure everything is fine
It's great that you're hearing the advice, but I can't take credit. I'm only giving you the same advice I got here, and I believe it was good. The really good comprehensive guides have been put together by @Archbid , you can see them in his signature. @BaliDawg has a bunch of important links in his sig that are very good too.

Absolutely check that motor thoroughly before spending a cent. These motors are good, but one single overheating event can damage them. Focus on that first... that's my advice.

Of course I'm not saying that subframe damage doesn't exist, and when I read back I see you used the term "extreme power", so the others were correct to mention it. As you are in school, you are planning to use this as a daily driver? If that's the case, just get it running right and you'll be very impressed.

My advice would be to get it running right in standard trim, forget about "extreme power" and most importantly don't drive like an arsehole. You don't want to kill some poor bugger who was just going to work or something.
 

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Discussion Starter #18
It's great that you're hearing the advice, but I can't take credit. I'm only giving you the same advice I got here, and I believe it was good. The really good comprehensive guides have been put together by @Archbid , you can see them in his signature. @BaliDawg has a bunch of important links in his sig that are very good too.

Absolutely check that motor thoroughly before spending a cent. These motors are good, but one single overheating event can damage them. Focus on that first... that's my advice.

Of course I'm not saying that subframe damage doesn't exist, and when I read back I see you used the term "extreme power", so the others were correct to mention it. As you are in school, you are planning to use this as a daily driver? If that's the case, just get it running right and you'll be very impressed.

My advice would be to get it running right in standard trim, forget about "extreme power" and most importantly don't drive like an arsehole. You don't want to kill some poor bugger who was just going to work or something.
Yeah I completely understand you and I will check out their pages and threads to see what I can learn from them. All I meant by extrem power was about 400 hp. I just want something that I can keep up with my car buddies with. They all drive 300+ hp cars and just disappear on me so I would like to just keep up reliably and not have to worry about terrible gas or anything
 
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