yes, there are several ways to do this but it is usually for rear alignment / camber... usually makes the mounting points more fragile if trying for too much adjustment. Always check these for cracks after a hard weekend. Curbs and off angle traction events (sliding through corners with grippy tires) puts a huge amount of stress on these mounting points. I have also seen where the whole rear subframe is raised... still tons of work for not much gain. These cars work best with the axle straight with the rear diff... stiff springs... 2 degree camber, 1/8" toe in.... not too low. Stiff springs = anti-squat
Yeah, the rear end from 2002 Underground is really nice...who can afford it though? It's my understanding that an E30 rear end can be modified easily for the 2002, it's stronger and you get the added benefit of its limited slip diff. Looks like your fabrication skills were all that was needed in the end though. Nice job. Subbed.
Thanks for the encouragement. For vintage racing got to use original brakes (drums) and they have plenty of stopping power. This mod is overkill for a street car, but mandatory for abuse on the track or high horsepower mod wanting to keep original trailing arms. 02s had available limited slip diffs, clutch style.
Hello Wayne, Great video! just starting to work on my 1972 2002. I'm going to add a larger late model BMW motor and I wanted your thoughts on strengthening the unibody if needed and where on the body to do it? Thank you for taking the time to share your knowledge. It's a great help for rookies like me.
The place I see failures now are the trailing arm pivot point on the rear frame... make sure you reinforce those too. The stock rear mounts to the body behind the diff in the middle and on the two sides. In the race cars we add a support in the trunk: a bar across near the top shock mount on both sides then a diagonal from both sides down to the middle. This stiffens up the rear, similar to a front shock tower brace. We also have a full roll cage that these points are tied too also. The front mounts were also tied into the cage. You can probably add some material to the side mount area and to the strap mount (in front of that point) as they are all under the seat and out of view.
This is heaps cool. I have been looking for subframe reinforcing videos. I want to do this to mine. Why nots drill holes through reunforcing plate at different places and plug weld for better adhesion?
Sure, plug welds could help on the reinforcement. Could also wrap it around the hub more too. The bottom seem is the weak point, or so it looks like from the failures. I will report back if these ever crack and where... may be a while, last set lasted 15 years.
Thanks for the feedback. I have been using a Gopro for my videos and its audio could be better... and I did adjust the audio, sorry if I missed a spot or two. I am just doing this for fun... and racing is my real hobby, and I have a day job
Nice job. Enjoyed the racing footage. Is there any more available? Just doing an m44/1.9 and ITB swap on my 1602 and was thinking of boxing some e21 trailing arms to use 323i rear discs. Mind you, have always found stock 02 brakes to be pretty good.
Yes, I have a whole channel of racing videos from our vintage racing, check it out and please subscribe ru-vid.com/show-UCpJnhTULz1bOKtSFemNWvgQ?view_as=subscriber
Wayne Siebrecht Thanks, I'll take a look. I've just picked up a set of 323i e21 trailing arms cheap so plan on fitting next year. My M44 swap is now mapped and made 182 bhp so should be fun. Would you suggest I box the e21 trailing arms before I fit them? #bmw16v02
@@Retrobeemer There are lost of options for no-stock upgrades. The Z3M look good too for strength and disk brakes. the e21 323I are great pieces and should handle your 182hp. Racing applications add another level of abuse more than just horse power. With stiff springs, sticky tires, curbs, dropping a wheel off the pavement and back on lead to some really high loads in the hub area. By the time the e21 323I came along ( and the turbo group 5 cars that used those too with mods) they had figured out how to make a proper trailing arm.
