Subframe Reinforcement Status Thread

[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.

[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.

[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.

[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.

[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:

[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.

[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)???

[clawhamm3r]

Mine didn’t have cracks. Not all of these cars do do and this was after tracking the car for 2 years. Reinforced anyway since I was replacing all the bushings and upgrading the suspension

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?

[jowo]

Vincebar or CMP are the best solutions right now.

Any underside reinforcement plate only is job half done, as it does not solve the inherent issue which causes the fracturing.

Important to note that the CMP Kit and the Vincebar Kit both offer the front mount reinforcement as well. This is often overlooked especially when only reinforcing only the underside.

I have a vincebar sitting in the box waiting to be installed alongside the PSDesigns underside plates.

Although, my experience has been that not many shops even know or care what the Vincebar or CMP solutions are, and so I’m having a hard time finding a trusted installer to carry out the work. Many shops just want the easy way or sticking to what they think has historial precedence. 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.

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

[BMWahba]

Vincebar or CMP are the best solutions right now.

Any underside reinforcement plate only is job half done, as it does not solve the inherent issue which causes the fracturing.

Important to note that the CMP Kit and the Vincebar Kit both offer the front mount reinforcement as well. This is often overlooked especially when only reinforcing only the underside.

I have a vincebar sitting in the box waiting to be installed alongside the PSDesigns underside plates.

Although, my experience has been that not many shops even know or care what the Vincebar or CMP solutions are, and so I’m having a hard time finding a trusted installer to carry out the work. Many shops just want the easy way or sticking to what they think has historial precedence. 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.

[Dash1]

OP, I recommend getting it reinforced. I had to persuade my friend to get it done with no visual cracks. Once the shop dropped the subframe and removed the weather coating there were huge visible cracks that had to be welded.

[timmo]

Drove my car around for a couple of years, and hairline cracks in the seam sealer in the LH wheel well caught my eye. Went underneath the car and found this:



Had Redish Motorsport plates installed along with new poly bushings. Then DIY'd the Vincebar to 100% bulletproof it for autox & track:

[Deen HK]

After purchasing I found out that mine had a hairline crack, after dropping the subframe there were a few more that were hidden. I decided to go with the Redish Motorsport plates as they have a good amount of surface area. I got them welded on instead of epoxied, with my previous cracks drilled and welded too.

[aapilcher]

I had the CMP stuff (Topside Beam Kit, Plates, and Frontside beam kit, underside plates) installed a couple months ago. My M3 has 72K miles, and the shop (SCR Performance in Loveland, CO) reported that no cracks were found

[karter16]

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.

Mine had cracks (approx 15-20mm) which I elected to drill and weld. I then bonded plates with structural epoxy. The rear mounting points of my RACP had previously had the foam done by BMW. There was no cracking in the rear mounts. The front mounts (which weren't part of BMW's foam procedure) had cracks. I plan to do the foam on the front mounts in the near future.