Subframe Reinforcement Status Thread

[Flat-Six]

If the RACP is solid, meaning no cracks, would the Mason bar alone be sufficient, or would you still need additional support (CMP/Reddish/Vince)???

[liam821]

If you don't drop the subframe and completely clean the RACP then you don't know for sure if you have cracks or not. Period.

Yeah this. It's really hard to see under there, and mine was heavy cracked under where the subframe mounted - you just couldn't see it without dropping the subframe.

[clawhamm3r]

Here's my front mounts at 92k, without even grinding it down. Suggest watching some reinforcement re-do videos where they cut out the plates from a previous reinforcement and expose the insides (the cavity that gets foamed) and see exactly why this happens lol. When I say I believe every one of these cars has cracks, I think they all have these starter cracks at the spot welds at this age. Unless you got one of them cars with 10 miles on it.

Note: should have color coded these arrows lol. Referring to the right side spot welds in both pics. Both front receivers had cracks, and you can see the really bad spot weld on the passenger side which actually ran up/out the side facing the diff when I ground it down to bare metal.

Remember this every time you see a FS ad that says "no subframe issues" lol. I don't claim to be an expert, just offering my opinion. Like I said, I helped a buddy do the repair and his did NOT pass visual inspection lol. Then I did mine, not expecting it to be as bad but also not expecting it to be flawless. I went with Reddish plates and the Mason X-Brace. All I can say is if you have a shop do it make sure it's one that specializes in this and knows what they're looking for. The big, obvious cracks are easy to spot, but I could see a regular shop easily overlooking all the tiny cracks and just welding plates in over top. Or maybe I'm just projecting because I'm not a professional lol.

Driver Front:


Passenger Front:

[Silbergrau metallic]

I have a 2005 M3 ZCP and don't know if I have any Subframe cracks or not, but I'm planning on having it reinforced just to be safe. Curious of what is considered the best and strongest method of doing this. I've looked at the Mason Bar and I like the look of it in the Trunk, so I was wondering the advantages or disadvantages of it are compared to a Vincebar or CMP reinforcing kit. With the Mason Bar, does it eliminate having to have the reinforcement plates installed.

[aapilcher]

Vincebar or CMP are the best solutions right now.

I’ve been contacting race shops and other similar fabricators who have the technical know-how. The thing is, it doesn’t require a rocket scientist to understand why these things work.

This is what I did, the shop that did my CMP install has a couple of with the e46 chassis race-cars (including M3's). They commented that it's a lot stronger and more comprehensive than the race cars they've built. My only regret is that now the "M-thunk" from the increased stiffness (also added Powerflex bushings at the same time) is very pronounced, to the degree that anybody who rides in the car asks if something is broken.

[LSBNick]

Currently trying to find a shop that can install either vincebar or CMP. Would prefer to do it all at once to really bulletproof the car.

[Stepstools]

It was hard enough to find a shop near Mississippi that would do rod bearings, so my hopes aren't high for subframe reinforcement. Maybe I'll wait until I'm out of the state in a year, but this thread is making me nervous about the rear end crunching noise I hear when I get out of my car.

[jbfrancis3]

Mine did not have any visible damage, nor any "real" damage when I ground it down to bare steel except for a single split spot weld and another spot weld starting to pull ever so slightly. This was just one corner (front, drive). Any vehicle is on the proverbial curve, its just comes down to timing and how rapidly it worsens thereafter. I used Lang Racing's plates and they were excellent, FWIW.

[Flat-Six]

I have a 2005 M3 ZCP and don't know if I have any Subframe cracks or not, but I'm planning on having it reinforced just to be safe. Curious of what is considered the best and strongest method of doing this. I've looked at the Mason Bar and I like the look of it in the Trunk, so I was wondering the advantages or disadvantages of it are compared to a Vincebar or CMP reinforcing kit. With the Mason Bar, does it eliminate having to have the reinforcement plates installed.

At this point in time, I do not have any RACP cracks, and I am wondering the same about the (full) MASON Bar....would it alone suffice????

[Fresh1179]

I had this job done about a month ago on my 06' with approximately 104k. I opted for the Redish plates based off of their reputation and quality. I had a local shop perform the job (I don't weld) and replace my rod bearings while everything was off the car. I think the choice of product that you use it is less of a structural integrity issue than an insurance policy. I haven't heard of any RACP failures with a welded vehicle, although I am certain that someone will correct me if I am wrong. That being said, I considered the CMP topside solution and am still looking at it for additional insurance. IMHO ,I would discourage solid bushings, and even super hard delrin bushings when you have them replaced unless the vehicle is exclusively a track or race car, otherwise you will be absolutely punished on the road. The car is significantly tighter after a plate reinforcement and poly bushings. I don't think you can go wrong with any of the choices.

[timmo]

At this point in time, I do not have any RACP cracks, and I am wondering the same about the (full) MASON Bar....would it alone suffice????

If the bar I'm looking at is the same as yours, I'm inclined to say not exactly. The rear points are tied together nicely with a straight-through bolt design, but the front is unchanged.

I had this job done about a month ago on my 06' with approximately 104k. I opted for the Redish plates based off of their reputation and quality. I had a local shop perform the job (I don't weld) and replace my rod bearings while everything was off the car. I think the choice of product that you use it is less of a structural integrity issue than an insurance policy. I haven't heard of any RACP failures with a welded vehicle, although I am certain that someone will correct me if I am wrong. That being said, I considered the CMP topside solution and am still looking at it for additional insurance. IMHO ,I would discourage solid bushings, and even super hard delrin bushings when you have them replaced unless the vehicle is exclusively a track or race car, otherwise you will be absolutely punished on the road. The car is significantly tighter after a plate reinforcement and poly bushings. I don't think you can go wrong with any of the choices.

When I had cracks I did extensive research, and found that there were a handful of cases where cars with just plates had RACPs that were starting to pop spot welds and separate, since those are the next weakest link. CMP or Vincebar are IMO the only two options that actually fix the root of the problem by transferring some of that load to the chassis rails.

[MrClutch55]

very interesting read, as of now, i have no visible crack. reading all the comments, i guess i will find out if there are any until i drop my subframe.

[trigtm]

I just finished with my RACP reinforcement with the turner plates installed below and the VinceBar installed above, both epoxied in. When I removed everything and cleaned the underside up, I have 0 cracks and I checked everywhere. I was absolutely amazed how clean the underside was of this car. 105k, Texas car that from what I can tell was never tracked or abused at all since everything is in nice shape.

VinceBar was easy to install and get in, the only trouble I had was all the bushings in the subframe which I did all of. I made a few tools to get them in and out copying the tools that people normally buy but that wasn't too bad. Pretty easy and straighforward install overall tbh. Great to do if you have time and the car isn't a DD. Needed two people to get the subframe back into the car but other than that, it was a 1 man job. Once I get the pics uploaded, I'll post of my before and after process.

[wahsm]

That'd be amazing if true, but send me pics of your front mounts and all those little spot welds that have tiny cracks radiating off of them before I believe it. How many miles?

I’ll see if I can find the pictures. Might have to contact the shop that did it as don’t remember if I took from my phone. I did see it with my own eyes before it was red forced. There was about 95600k miles 154k km since it is a Canadian car. The original owner I bought it from did baby the car. Although I did have a nasty shearing on some bolts when I rebuilt my vanos. May post that this weekend. One more track day could have done in the engine.

[wahsm]

Agreed. Anyone know of any trusted shops/mechanics in Canada (particularly west coast) that has done a CMP subframe reinforcement?

turn3autosport did an excellent job on mine. Also Nixon and CG Motorsports are great shops as well, but don’t have first hand experience on subframe reinforcement from those two.