BMW BTCC Inspired Track car
Posted: Wed Oct 19, 2016 3:10 pm
I've had a few people ask about this car, and I've not posted a build thread anywhere because I don't really post anywhere else, so here goes.. I'll post a bit at a time and hopefully by the time I catch-up to "current day" it will be on the road and running!
This car started as a cheap track toy, I did a few track days in it, then pulled it off the road to rebuild the LSD... ...which is where it all went wrong!
Rear end came out, was disassembled, and the suspension bits sent off for sandblasting..
While this was out, I decided to weld in the rear suspension reinforcement pieces - they have a tendancy to tear the rear boot floor, so BMW kindly made some strengthening plates which can be brought fairly cheaply.
One of the rear-most plates being held in position ready for welding..
Here you can see 3 of the 4 plates where the subframe mounts..
I also did the rear trailing arm mounts while I was in there - these are 4x bosses which pass through the floor and are welded in on the inside. Again they can tear out or crack around the root and are hard to diagnose before its too late, so AKG strengthening plates purchased and welded in.. This basically levels the area where the trailing arm "cup" mounts, and so doesn't alter the geometry however it does need flattening off properly so you're not twisting the brackets and pinching the bush/bolt. Not the best picture, this was prior to dressing it all and had been given a quick blast of paint as I was off with work for 2 weeks to Canada and didn't want it sitting there un protected!
When I got finished with this welding, I decided to stitch all around the rear end where the panels passed near mounting points and things - this was done with roughly 1/2" weld, 1" skip, effectively tying the whole array of rear end suspension mounting points in to the rear of the cills and the transmission tunnel. Don't really have any pics of this sorry..
I also cut the top damper mounts out and fitted some offset mounts from Amspeed - these are only really needed with true coilover rear suspension, however it moves the top mounting point across about 15-20mm and gives some more clearance to the inside in the back end, which seemed like good insurance with the larger adjustable damper bodies I had fitted
After that, everything under the car got cleaned-up - fortunately the shell is in really good shape with no rust to worry about
This car started as a cheap track toy, I did a few track days in it, then pulled it off the road to rebuild the LSD... ...which is where it all went wrong!
Rear end came out, was disassembled, and the suspension bits sent off for sandblasting..
While this was out, I decided to weld in the rear suspension reinforcement pieces - they have a tendancy to tear the rear boot floor, so BMW kindly made some strengthening plates which can be brought fairly cheaply.
One of the rear-most plates being held in position ready for welding..
Here you can see 3 of the 4 plates where the subframe mounts..
I also did the rear trailing arm mounts while I was in there - these are 4x bosses which pass through the floor and are welded in on the inside. Again they can tear out or crack around the root and are hard to diagnose before its too late, so AKG strengthening plates purchased and welded in.. This basically levels the area where the trailing arm "cup" mounts, and so doesn't alter the geometry however it does need flattening off properly so you're not twisting the brackets and pinching the bush/bolt. Not the best picture, this was prior to dressing it all and had been given a quick blast of paint as I was off with work for 2 weeks to Canada and didn't want it sitting there un protected!
When I got finished with this welding, I decided to stitch all around the rear end where the panels passed near mounting points and things - this was done with roughly 1/2" weld, 1" skip, effectively tying the whole array of rear end suspension mounting points in to the rear of the cills and the transmission tunnel. Don't really have any pics of this sorry..
I also cut the top damper mounts out and fitted some offset mounts from Amspeed - these are only really needed with true coilover rear suspension, however it moves the top mounting point across about 15-20mm and gives some more clearance to the inside in the back end, which seemed like good insurance with the larger adjustable damper bodies I had fitted
After that, everything under the car got cleaned-up - fortunately the shell is in really good shape with no rust to worry about