MRT Roll center kit

[TheDirtyS54Thirty]

What are your opinions on using this kit in a time attack car? Is this strictly a drift part because of the increased steering angle? What If I use steering rack reducers to bring the steering angle back or close to stock?

https://catuned.com/mrt-bmw-e30-e36m-roll-center-bump-steer-angle-kit

[Digitalwave]

Roll center correction is always smart on a lowered car, especially with one that is very sensitive to camber gain and other sweep factors like an E30 is. On E30 M3 struts, you can simply add a spacer (usually 1/2", 3/4", or 1") between the strut and the steering knuckle. On non-M's, it would have to be some sort of kit like this. An angle kit would probably serve the purpose as it essentially does the same thing as a what I described for an M3. My 2 concerns would be 1) It might actually be TOO much correction @ 30mm (about 1 1/4") and 2) It drastically changes the steering pickup point. I don't really know how that would change ackermann, bump steer, and overall steering feel for track usage. You probably wouldn't need to add rack stops, as unless you space your wheel out a ton (like drifters do), you'll just rub on the frame rails when you get to too much lock.

For the rear of the car, I have been happy with my Condor 12mm subframe riser bushings. I have very acceptable toe and camber in the rear with the roll center correction the higher subframe offers. My car is only moderately lowered.

CATuned says you only need 15" wheels to clear their kit, but that seems off to me. It may be because they move the steering pickup point backwards (away from the wheel) a good bit. I have minimal clearance with 16" wheels and 13mm roll center spacers on my car (E30 M3 struts).

[Jean]

I think if you don't need the steering angle or not looking to drift you can also go with the bump steer correction kit that GC makes as well.

[TheDirtyS54Thirty]

I think if you don't need the steering angle or not looking to drift you can also go with the bump steer correction kit that GC makes as well.

Ha unfortunately I saw the GC alternative after the fact. I had the MRT kit installed last Thursday and the car aligned at the same time. Honestly the car steers pretty damn well in the race setting and the control arms are flat now with the car being very low. I also gained some of that steering feel that was lost after upgrading from 225s to 245s up front.

[e30davie]

The ae86/ke70 guys put similar kits on their cars. I had RCA spacers as well as shorter steering arms to quicken up the steering in my ke70. Easier than swapping the racks.

That kit looks nice. Only concern is that you now are using non oem steering components. You just have to hope they have done their homework and its strong enough.