1055 wrote:
its kind of scary - funny - scary how many videos come up when you search "m3 snap oversteer" in youtube
Yeah. It's a huge problem. Many cars have been sent to the grave. The various forums are downright depressing! I noticed a very big change with the poly RTABs on my car. I didn't get any faster, the break-away was way less progressive and made it scary to push the edge, and then I got slower. I don't think they are a good solution if you're serious about going fast. Poly RTABs also increase the occurrence of the rear trailing arm pockets tearing out. OEM rubber for street cars, or spherical bearings for track use are my recommendation. The LCABs were much less dramatic in their handling alteration, but they just made things harsher and I didn't really feel like the steering was much better for it. I should preface this with the fact that I never ran slicks or oversized tires (only 235-40-17 in sticky street rubber), so I didn't have massive grip deflecting the LCABs. I think there is a good chance that poly LCABs would make a decent solution for handling big slicks and unlike the RTABs, the LCAB is a decent place (designwise, no binding caused) to use polyurethane. Oh and did I mention that they squeak after a while and you need to disassemble and re-grease it all? It took less than 3k miles and a couple snowy days for that charming trait to rear its ugly head. OH and the car developed a significant number of new rattles which went away when I took the poly off.
I replace my LCABS and RTABS every 40k miles. They cost ~35 a set (~70 for front and back). It's not a significant cost and it keeps the car handling like it should.
Advice I would give to someone just about to rebuild their suspension. Don't do the rear subframe bushings! I pulled my subframe at 130k and the bushings had no cracks and no visible damage. They were really difficult to remove even with a press and it took hours to get them out. Save the money, aggravation, and time and spend the money on something better, like good shocks.
I'd also recommend an x-brace, and a front tower brace (of good design). They do make a significant difference. The rear tower brace, on the other hand, does nothing.
If you've driven a plain E36 and liked it, then the M3 will be similar with a bit more of everything. I've also been able to push my M3 consistently up to 30mpg on highway, and my record on a tank of gas is 42mpg. A typical mixed driving tank yields 25mpg. When I flog it on the street I'm at 19mpg. If your mileage sucks, it's your driving or a good sign the engine needs some love.
Reading this over I realize I'm kinda harping on the poly thing. Guess I'm still sore after all these years that I paid the extra money for poly and it felt like I'd made the car worse.