How is this subframe crack?

[01SG]

Found this while dropping the differential today. Can anyone recommend a good shop in the New York area?

[Syfon]

Damn. Make sure it's repaired properly (i.e. stop-drilled and welded etc etc). Also make sure you reinforce the racp from above and brace it correctly. Remember, plates don't fix the issue.

[jbfrancis3]

Yikes. Not familiar with your area but Rogue Engineering in NJ comes to mind.

[01SG]

I'm thinking about buying the whole CMP kit; I want to do this once and forget about it. So that's the underside reinforcements, the topside bar, plus the extension for the two front mounts. I understand their solid bushings are tolerable for a street fun/weekend car as well?

I was considering Rogue. I'll definitely give them a call, among others. I'm willing to travel to a place that has lots of experience for this; I hate to take my car to a shop for any little thing..

Once the differential is out I'll get more pictures, so far there's no other cracks. I suppose it's par for the course, time for winter hibernation anyway, and come spring every bit of the suspension will have been replaced and the floor reinforced.

[Syfon]

I'm thinking about buying the whole CMP kit; I want to do this once and forget about it. So that's the underside reinforcements, the topside bar, plus the extension for the two front mounts. I understand their solid bushings are tolerable for a street fun/weekend car as well?

I have the entire CMP kit in my car; plates, topside bar, front mount extension, 6 point brace, solid raising subframe bushings.

Rear end is going nowhere lol. As for the solid subframe bushings, you hear the faintest of diff whine, but this isn't really heard over my exhaust (it's pretty loud). I've stayed with OE diff mounts.

I felt an immediate difference once all was in and aligned. Car almost felt a bit twitchy in the rear as it's so tight now. Front end feels comparatively loose imho.

[Nick_P]

I live in Stamford, CT used to live in NYC and have always taken my car to TKX in Long Island...they've done my subframe reinforcement, Vanos, Rod Bearings etc. It's bit of a drive from where I live now but they are very familiar with our platform. I've heard good things about Hi-Speed Motorsports as well, but never used them myself... they're in Milford CT

[eacmen]

I live in Stamford, CT used to live in NYC and have always taken my car to TKX in Long Island...they've done my subframe reinforcement, Vanos, Rod Bearings etc. It's bit of a drive from where I live now but they are very familiar with our platform. I've heard good things about Hi-Speed Motorsports as well, but never used them myself... they're in Milford CT

+1 for HSM. Never used them personally but seem to know what they're doing in the interactions i've had with them.


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[poss]

I'm thinking about buying the whole CMP kit; I want to do this once and forget about it. So that's the underside reinforcements, the topside bar, plus the extension for the two front mounts. I understand their solid bushings are tolerable for a street fun/weekend car as well?

I was considering Rogue. I'll definitely give them a call, among others. I'm willing to travel to a place that has lots of experience for this; I hate to take my car to a shop for any little thing..

Once the differential is out I'll get more pictures, so far there's no other cracks. I suppose it's par for the course, time for winter hibernation anyway, and come spring every bit of the suspension will have been replaced and the floor reinforced.

CMP is very arguably the best-engineered permanent solution. However, I didn't want to lose boot space so went with stealth bar. Its relatively easy to make one. One of my mates welded it up for me.

I have a convertible, so only needed rear top reinforcement, but coupes apparently need front and rear RACP reinforcement on top. CMP is the only one that offers both to my knowledge.

And yes, with new bushings it stiffens up the backend nicely...

[01SG]

Thanks for the suggestions, I'll be sure to check those places out. I saw the CMP bushings were for lowered cars, so I might just go OE or Turner's. I wanted to order it all from one place, but since that's out I'll look at the Vincebar too. His kit also has the gussets to accomplish both front and rear reinforcement on top. I'm going to find a shop with experience and see if they have a preference; it appears they will both do the job.

I cleaned things up a bit and poked around some more after dropping the diff. I found another crack, predictably around the front right subframe bushing, in between that and the gas tank.

[clawhamm3r]

You'll probably find a dozen more after grinding everything down. Pay special attention to the spot welds around the mounts, you'll see tiny cracks radiating out like a pinwheel.

[poss]

I saw the CMP bushings were for lowered cars, so I might just go OE or Turner's. I wanted to order it all from one place, but since that's out I'll look at the Vincebar too. His kit also has the gussets to accomplish both front and rear reinforcement on top. I'm going to find a shop with experience and see if they have a preference; it appears they will both do the job.

I cleaned things up a bit and poked around some more after dropping the diff. I found another crack, predictably around the front right subframe bushing, in between that and the gas tank.

The gussets will add some reinforcement to the front of the subframe but you will still be relying upon sheet metal to transfer forces to the chassis rails (which is why CMP offers both front and back bars)

I used Powerflex black for subframe bushings and really like the improvement

[01SG]

So CMP is truly the most effective design? I did appreciate all the articles on the website; would like to see that eighteen page installation manual.. They have the underside reinforcement, topside bar, and top extension, and also these Subframe/RACP to chassis rail plates; that should cover everything then?

I might throw in the six-point bar for the hell of it, something extra to look forward to after such a pain in the ass.

[AussieE46M3]

So CMP is truly the most effective design? I did appreciate all the articles on the website; would like to see that eighteen page installation manual.. They have the underside reinforcement, topside bar, and top extension, and also these Subframe/RACP to chassis rail plates; that should cover everything then?

I might throw in the six-point bar for the hell of it, something extra to look forward to after such a pain in the ass.

Feel free to email me or shoot me a message via Facebook.

I have a bunch of parts arriving for E36, E8X/E9X as well as F2X/F3X and intend to do a big sale in the near future but, if you're wanting to get onto it sooner I can do you a good deal now.

Here's a link to the Facebook page. https://www.facebook.com/cmpauto

Otherwise my Email is: info@cmpautoengineering.com

Look forward to hearing from you!

[poss]

So CMP is truly the most effective design? I did appreciate all the articles on the website; would like to see that eighteen page installation manual.. They have the underside reinforcement, topside bar, and top extension, and also these Subframe/RACP to chassis rail plates; that should cover everything then?

I might throw in the six-point bar for the hell of it, something extra to look forward to after such a pain in the ass.

I did a huge amount of research on this issue when I discovered the same RACP cracking issue in my newly-purchased (slightly-used) M3 with less than 50K miles on the clock - the big difference being that I bought 2nd hand from a BMW Dealer who told me the vehicle had been fully checked. They lied.

After threatening to sue the BMW Dealer we reached an amicable arrangement. I did not go with the CMP brace in the end because it intruded into the boot space (so that it creates the strongest connection to the chassis rails). I did go with the CMP underside plates tho - the installer complained they were too much work to install as they were so heavy-duty/thorough in their design.

[01SG]

Feel free to email me or shoot me a message via Facebook.

I have a bunch of parts arriving for E36, E8X/E9X as well as F2X/F3X and intend to do a big sale in the near future but, if you're wanting to get onto it sooner I can do you a good deal now.

Here's a link to the Facebook page. https://www.facebook.com/cmpauto

Otherwise my Email is: info@cmpautoengineering.com

Look forward to hearing from you!

I'm actually putting the car away for winter now, so I don't intend to have the work done just yet. I'm certainly going to collect the material early though, was thinking the end of this month; when is the big sale you mentioned? I'm definitely interested in the near future and would gladly take advantage of that.. I was going to email you, but figured other people might want to know too! Thanks for reaching out, your work looks top notch.