Subframe reinforcement
 

Ok folks,
With the CSL currently going under a restoration project I am contemplating fitting the reinforcement plates to the subframe mounts.

The car had a new panel fitted by BMW Elms and had the foam / Resin injection at that time. Upon dropping the sub frame the mounting points look perfect.

Now is it as good idea to fit these plates now while it is all stripped?
What will happen to the foam / Resin with the welding?
Should I leave as is and fit Polly bushing to give a flat surface for the subframe to mate to the panel?

Just don't know, I was tempted to just leave it all OEM but have been advised otherwise.
Anyone done anything similar?
Be interested to hear from anyone that has done the plates post foam / Resin injection.

Ta.

lad Had his plated up, after new floor was fitted by bmw,, they wouldn’t refit a new floor again foc. So they welded plates,, they had done the resin first time,, But personally if it was mine if your floor is good, I’d probably just fit some solid subframe. Bushes. From memory mike recommended the akg solid bushes. I’ve bought some for my Trackday build. And they are superb quality,, iv fitted them in ,, But not tried them yet. But that’s what I would fit next in the csl subframe. They give a good wide surface. Ps I’ve also plated Trackday car build as it was cracked ,, but would be happy to fit to the csl for sure ,, could send pictures of them fitted in subframe is you need to see how they look :smokin:

To add to this after doing the plates on track build. Welding them up myself and doing the inner reinforcement plating work, unless you take off the inner top skin you can’t really do a proper paint protection where you’ve welded and burning off the paint inside, so I think just welding plates on the outside will speed up corrosion if not properly protected,, Also welding the plates I recon weakens the makeup of the oem metal sections,, Saying this the reddish plates I used I can’t fault ,,

^^^This^^^ along with the thought that I'd be melting the Foam / Resin and rendering that part of the "fix" useless is whats causing me to question doing it.

Just curious to see folks thoughts and also see feed back now on whether the OEM repairs are still holding out after a few years.

On my race car it has the plates however it also has a weld in cage and I had that tied into the 4 mounting points. The sub frame actually bolts to the cage rather than the car as its all welded together. I don't want solid bushes on the CSL though.

There is an alternative to welding (which I too would be nervous about with the resin injection) and that is the Vince Bar epoxy kit. Part 2 is straight after :).

https://www.youtube.com/watch?v=AqmzEna5rrM

. As mentioned previously I personally don’t think the resin is perfect. As lads failed again,, but will never really know how well resin was installed, but it was done by a bmw body shop,, as was the second plate repair,, :whistle:

You should do the plates, either epoxy or weld and then do the vince bar epoxy or weld kit.

Regarding the solid subframe bushes ,, after doing the plates on track build car myself, and properly looking at the structure of the subframe bush fixing area,, personally I think the solid wide bushing is a better option than the std rubber bushes, personally I believe as the std rubber bushes start to soften / moor movement in subframe happens eventually cracking on original panel around bolt points and wider area, Definitely if plated I’d go solid bush on csl ,, only disadvantage possibly a slightly bit more road noises through the car , but I’m sure it would tighten up the rear end,that has to be a bonus :smokin:

Chris chadwick on cutters is doing a really neat option. Well worth looking at :smokin: Ps not related

Have you considered the Gosling Racing Brace?
Doesn't have to be full cage but the brace that fits between strut tops and diff mounts is highly rated.