2002 S54 BMW M Coupe Build Thread

[KBH22102]

Rogue Engineering might still have some of their dual ear diff covers in stock since you are doing the subframe job.

[moupe54]

Hey Nick, love your coupe! Question about your 130R if you don't mind....How did you handle the horn wire? Did you just have a long brown/red wire? I got a 130R and using a long wire, but it seems it might get tangle eventually....Thanks in advance

Hey, if I remember correctly, I had some issues with my horn wire aswell. I used butt splices to lengthen the power and ground and it seemed to work. hope this helped!

As someone who has enjoyed my 6 speed with 3.15 for 6+ years now...

You must do a ton of highway driving because that part definitely was nice. Car was super smooth and quiet at 90 mph haha. I did the 6 speed entirely so I can run a shorter final drive. I cant hear enough times that its the "Poor Man's Supercharger".

Rogue Engineering might still have some of their dual ear diff covers in stock since you are doing the subframe job.

I would get one if thats the direction I choose. I am 95% set on just doing a reinforced single ear. The dual ear doesn't clear the stock mufflers and thats a hill I'll die on. I love the quiet exhaust/loud intake combo and the fitment of the stock tips is perfect to me. I have also seen many RF dual ears hang way too low making the diff the lowest point in the car. Mine is really low and I fear I would smack my brand new diff on a manhole cover here in NY. I have my reasons, although most will disagree.

[bubela]

I made my own set up using the stock/single ear diff cover in my turbo M52 ti. Been holding 425wtq+ and a hundred plus 1/4 mile trips and 25k miles without issue. Don't worry.

[ProductUser]

Hey, if I remember correctly, I had some issues with my horn wire aswell. I used butt splices to lengthen the power and ground and it seemed to work. hope this helped!



You must do a ton of highway driving because that part definitely was nice. Car was super smooth and quiet at 90 mph haha. I did the 6 speed entirely so I can run a shorter final drive. I cant hear enough times that its the "Poor Man's Supercharger".



I would get one if thats the direction I choose. I am 95% set on just doing a reinforced single ear. The dual ear doesn't clear the stock mufflers and thats a hill I'll die on. I love the quiet exhaust/loud intake combo and the fitment of the stock tips is perfect to me. I have also seen many RF dual ears hang way too low making the diff the lowest point in the car. Mine is really low and I fear I would smack my brand new diff on a manhole cover here in NY. I have my reasons, although most will disagree.

This has been discussed before. Per RF, and if my memory is still okay, the front valance, at least on the roadie, is the lowest point.

[durianburger]

Sure helps, good to know how others handle the wiring, thanks Nick!

[moupe54]

I made my own set up using the stock/single ear diff cover in my turbo M52 ti. Been holding 425wtq+ and a hundred plus 1/4 mile trips and 25k miles without issue. Don't worry.

Yeah, I'm not too worried about it at all. Will most likely be sticking to single ear.

This has been discussed before. Per RF, and if my memory is still okay, the front valance, at least on the roadie, is the lowest point.

Yeah I'm aware. Depending on which installer used on a RF kit, sometimes the diff hangers are left a bit too low, trust me ive seen it. Ive been in a friends car and smacked a diff on the ground at 80 mph. It's not fun. The main reason I'm sticking to single ear is the exhaust.

[moupe54]

So as stated in a previous comment, I was going to just install my new diff when my subframe was dropped and being reinforced. I got antsy and wanted to sell my old diff before I dropped another few thousand on the reinforcement job, so I decided on a whim to switch the Diffs out...



Goodbye crusty, stock 3.15 LSD. You treated me well and got me great fuel economy, but needed to go
For the milage and age of this stock differential, like a lot of other parts off this car, its in great shape! someone make me an offer on it so I can get it out of my garage!
Due to me still using my stock diff cover, I obviously wanted to make it look brand new again, so luckily I have a friend with a media blaster, and was able to make it happen!



I've been told that I could just seal up the new LSD with the fresh cover using some RTV or Permatex, but I wanted to do it like the factory and bought the OE gasket and waiting to seal it back up.
BMW part number: 33111211708
I also put a dab of gasket maker on for good measure.



Since I had a few days of down time waiting on the paper gasket to show up, I restored all of the hardware associated with the job and damn does it look good all sealed up!



After the 2 quarts of Redline Gear Oil has been poured into the fresh LSD, she's ready to go in. I used a level and you're supposed to open the upper plug and fill it until it starts to spill out.




And she's in!
Spending all this time under the car makes me realize how bad I need to clean some stuff up like the exhaust. Sheesh does it look tired. Ill be sure to bed liner the whole undercarriage and restore everything shortly when the time comes for the Subframe.
I now need to break this LSD in, and change the fluid. The break in procedure is apparently just go and do figure 8's in a parking lot until the clunking goes away, then change the fluid. Looking forward to driving this thing!
Thanks for Viewing

[IndianaRoadster]

When I had my mine out I cleaned my cover up also but wanted it to stay looking good for a long time. So I bought a rattle can of clear wheel paint and gave it a couple coats of clear. It's been over two years now and still looking new.
20190205_165820.jpg
20200410_162220.jpg

[BlueM3Racer]

Sorry to hear of your subframe troubles, Nick. Know that you'll get it sorted and back to "better than new" status soon. Love this thread. Thanks for all the updates & thorough documentation.

[BimmerBreaker]

Next time I get caught doing donuts, I'm going to say I was breaking in a diff...

Nice build, going to be really great once the subframe is done!

[moupe54]

When I had my mine out I cleaned my cover up also but wanted it to stay looking good for a long time. So I bought a rattle can of clear wheel paint and gave it a couple coats of clear. It's been over two years now and still looking new.

this looks great! I probably should have rattle can cleared mine aswell, oh well. Maybe when I change my fluid next time I'll do it.

Sorry to hear of your subframe troubles, Nick. Know that you'll get it sorted and back to "better than new" status soon. Love this thread. Thanks for all the updates & thorough documentation.

It's alright! honestly its something we all have to expect to do on these cars at some point, just financially its annoying because of the offensive amount of money I just blew on this driveline swap. Thanks for the kind words though, I love that people follow it now, makes the updates all the more fun!

Next time I get caught doing donuts, I'm going to say I was breaking in a diff...

Nice build, going to be really great once the subframe is done!

hahaha thats one way to do it! Thanks man I appreciate it, cant wait to have it done and enjoy the thing for once

[robb1887]

Yeah I'm aware. Depending on which installer used on a RF kit, sometimes the diff hangers are left a bit too low, trust me ive seen it. Ive been in a friends car and smacked a diff on the ground at 80 mph. It's not fun. The main reason I'm sticking to single ear is the exhaust.

Randy F. has done plenty of dual ear with stock exhaust. Required a little hammering or trimming back the double wall exhaust piping. Changes no tone or level of volume.

Jussayin. Use this information as you choose, but I'd do a dual ear.

[moupe54]

With the date for my car to go in settled (08/27/21), preparations began. I usually like to get as involved in the projects done to my car even if I can fully complete them myself. In this case, I can weld, but I'm not confident enough to do it to the caliber I expect for this car.
My plan: I'm keeping my reinforcement really simple for now, at least for me. I wanted to go absolutely nuts with my suspension when originally planning this job, but I have to simplify for the time being to get the car back on the road. All ill be doing this time around is:
Randy Forbes Subframe Reinforcement Kit
Rebuilding my axels (boot is torn drivers side)
fixing my shifter alignment with a modified selector arm
New OEM Subframe Bushings
Garagistic Camber/Caster Adjustment Weld ins
Dynamat and Bed liner



In a few months after I recuperate financially, i'll have a crazy suspension refresh planned but this is going to have to do for now.
first up was gutting the interior, which I have done maybe 15 times now. I have been through this job before on my previous m coupe so I am no stranger to the process about to be done. Only about an hour and I had everything out.




Now that I removed half of my m coupe, came time for the crappiest part of the whole job, removing the gross sound deadening and seam sealer hiding the failing welds. I had an air hammer but it sucked so the ol' hammer and chisel was the strategy for me. Once all that was gone, a classic grinder got rid of all the paint. In this situation its not really necessary to strip the whole floor, just really in the spots that needed to be welded. Still debating on getting some lacker thinner to really get rid of all the crap, but we'll see.



ya'll can only imagine how I feel having something look this ugly on my coupe, I'm gonna be sick



This image is really just to point how where my car's floor failed. To reiterate, I don't abuse my car at all...All it really sees is straight line acceleration and it STILL failed! Truly disappointed in BMW for designing this car like absolute garbage. Just leaves more stuff for me to fix and make better than ever.
I'm really excited for the finished product. I ordered a TON of dynamat sound deadening to re-cover everything plus more. I plan on doing the whole floor and shock towers, and to top it off spray it with some thick bed liner. Weight reduction who?

****update****
did a bit more prep to the rear before dropping the car off today. Welds are only as good as the surface you're welding on!



Thanks For Viewing, Wish me luck!

[BimmerBreaker]

Depending on which installer used on a RF kit, sometimes the diff hangers are left a bit too low, trust me ive seen it. Ive been in a friends car and smacked a diff on the ground at 80 mph. It's not fun. The main reason I'm sticking to single ear is the exhaust.

How would the installer do that? If the rear hangar is too low, the front of the diff won't bolt flush to the subframe. Based on what I was researching for my own projects, doing this would also cause driveshaft vibration because the flange angle would be off relative to the transmission and the driveshaft phasing would be out of sync

There is one and only one, position for the diff hanger(s). Perhaps your friend's car was simply lowered too much...



Good work on getting it reinforced though! The trunkfloor seems to have pulled out a good amount so makes sure to double check alignment and everything when putting in the reinforcement kit. There may be some chassis repair needed in the prep phase

For sound insulation, applying it on the trunkfloor and shock towers is good, but the best way to reduce interior cabin noise is to put some inside the door panels, floorboard and roof
I also wouldn't spray anything over dynamat. The paint or bedliner won't adhere to the backing of it properly. You should paint the chassis around the repair then put the insulation material over it and leave it

There are also thinner, lighter sound insulation materials than dynamat you may want to research. I was big into car audio when I was younger and have dabbled in a lot of those sound insulation materials trying to keep my subwoofers from rattling my license plate. That was also over a decade ago now, but even back then, there were better choices than dynamat. Dynamat is just butyl with an aluminized backing layer. You can literally just buy rolls of butyl, it's the same stuff without the backing. Or you can shop around and find brands that sell the same butyl material, but with a black backing for example (I assume that's why you wanted to paint it?)

[ProductUser]

Originally Posted by z3coupenick
Depending on which installer used on a RF kit, sometimes the diff hangers are left a bit too low, trust me ive seen it. Ive been in a friends car and smacked a diff on the ground at 80 mph. It's not fun. The main reason I'm sticking to single ear is the exhaust.

Having installed Randy's kit, I'm calling shenanigans on this. Randy's install instructions are very detailed, so unless the installer really mucked something up, there's another reason for the diff to hang so low.

[moupe54]

How would the installer do that? If the rear hangar is too low, the front of the diff won't bolt flush to the subframe. Based on what I was researching for my own projects, doing this would also cause driveshaft vibration because the flange angle would be off relative to the transmission and the driveshaft phasing would be out of sync

There is one and only one, position for the diff hanger(s). Perhaps your friend's car was simply lowered too much...



Good work on getting it reinforced though! The trunkfloor seems to have pulled out a good amount so makes sure to double check alignment and everything when putting in the reinforcement kit. There may be some chassis repair needed in the prep phase

For sound insulation, applying it on the trunkfloor and shock towers is good, but the best way to reduce interior cabin noise is to put some inside the door panels, floorboard and roof
I also wouldn't spray anything over dynamat. The paint or bedliner won't adhere to the backing of it properly. You should paint the chassis around the repair then put the insulation material over it and leave it

There are also thinner, lighter sound insulation materials than dynamat you may want to research. I was big into car audio when I was younger and have dabbled in a lot of those sound insulation materials trying to keep my subwoofers from rattling my license plate. That was also over a decade ago now, but even back then, there were better choices than dynamat. Dynamat is just butyl with an aluminized backing layer. You can literally just buy rolls of butyl, it's the same stuff without the backing. Or you can shop around and find brands that sell the same butyl material, but with a black backing for example (I assume that's why you wanted to paint it?)

Yeah that was the reason I wanted to paint it, I just don't like the look of it, although I do hear everywhere that it works the best. I did think about that, the bed liner not adhering well to the back of the dynamat. If I cant figure out a "prettier" solution then its okay, its all covered anyway. On my last car I bought a different material and it was gross, so I just thought the dynamat would suit my needs. I understand that all this stuff is heavy, but the 30 lbs or so really is negligible. I think a quiet trunk is worth the sacrifice. As for the the diff on the other cars hanging too low in my opinion, I swear I'm not crazy. Both cars I'm referring to had the Rouge engineering cover which maybe that specific cover with the fins attached hung lower than your typical E36 hanger.

Originally Posted by z3coupenick
Depending on which installer used on a RF kit, sometimes the diff hangers are left a bit too low, trust me ive seen it. Ive been in a friends car and smacked a diff on the ground at 80 mph. It's not fun. The main reason I'm sticking to single ear is the exhaust.

Having installed Randy's kit, I'm calling shenanigans on this. Randy's install instructions are very detailed, so unless the installer really mucked something up, there's another reason for the diff to hang so low.

I swear these cars had crazy low diff covers. I'm realizing now that both cars had the rouge engineering cover with the fins. So I'm thinking that might by why.

[ProductUser]

Yeah that was the reason I wanted to paint it, I just don't like the look of it, although I do hear everywhere that it works the best. I did think about that, the bed liner not adhering well to the back of the dynamat. If I cant figure out a "prettier" solution then its okay, its all covered anyway. On my last car I bought a different material and it was gross, so I just thought the dynamat would suit my needs. I understand that all this stuff is heavy, but the 30 lbs or so really is negligible. I think a quiet trunk is worth the sacrifice. As for the the diff on the other cars hanging too low in my opinion, I swear I'm not crazy. Both cars I'm referring to had the Rouge engineering cover which maybe that specific cover with the fins attached hung lower than your typical E36 hanger.



I swear these cars had crazy low diff covers. I'm realizing now that both cars had the rouge engineering cover with the fins. So I'm thinking that might by why.

Good point.

[robb1887]

Yes the Rogue cover has larger fins from an OEM.

Also, look into Noico over Dynamat. Same stuff and half the price.

As far as sound deadening goes you can also cover the butyl with closed cell foam to help reduce noise as well. I did my entire cabin in my last Tacoma before I sold it and did specific application of it to the Coupe. The foam also helps with heat from radiating through the roof if you were to drop the headliner to apply it.

[moupe54]

I finally got a picture of my friends old coupe with the RE Finned cover that clearly shows how low the diff sits...supporting my original claim.



Here, you can see its the lowest part of the car. I spoke to him today about it and he said he hit the diff on full compression at least 10 times. This is what originally swayed me away from doing the dual ear mount. I Still want to maintain my stock exhaust without hacking it up so I am sticking to my original plan, for it is just fine.
Car has been dropped off and is set to be completed in about a week.

I miss driving

[IndianaRoadster]

I'm doing the RF reinforcement this winter and sticking with the single ear dif cover. I'm doubling up the dif mount by welding a new one over the old one. That exponentially increases the strength. Once Randy's kit is welded in which keeps the floor from moving, I can't believe the dif mount doubled up is going anywhere

[MartyBtoo]

There is a finless dual ear diff cover that is used in M3's, if you want the dual ear functionality without the ground clearance issue. Should be just fine for street use.

Marty

[lapoune]

I finally got a picture of my friends old coupe with the RE Finned cover that clearly shows how low the diff sits...supporting my original claim.

Here, you can see its the lowest part of the car. I spoke to him today about it and he said he hit the diff on full compression at least 10 times. This is what originally swayed me away from doing the dual ear mount. I Still want to maintain my stock exhaust without hacking it up so I am sticking to my original plan, for it is just fine.
Car has been dropped off and is set to be completed in about a week.

I miss driving

I think you made the right choice. I don't get how people are saying these don't scrape. Either you'd need perfect roads or rock hard suspension. I've scraped mine countless times, and I've seen a couple cars on BAT with the rogue cover that are beat to shit from scraping also (some installed by randy himself, so no argument about improper install there).

Wish there was a Z3M style cover with dual ears...

[MartyBtoo]

(snip) Wish there was a Z3M style cover with dual ears...

Did you read my post just before yours?

Marty

[lapoune]

Yes I know about it, which is why I mentioned Z3M (so with fins). I will probably switch to the e36 dual-ear cover eventually.

[IndianaRoadster]

Maybe I'm way off base here, but my z3m cover is connected by two "ears", one in front and one in the rear of the bushing itself. When I look at pics of the double "ear" covers and the way they are connected it looks to me that each bushing has only one "ear" per side. So wouldn't that in a way make them equal in the sense that both ultimately have a total of two "ears" each?