E36M3 STR build

[Kaizen81]

It's Tristan's old diff when he won STU Nationals. 30/90 3 Clutch with custom preloads. Difference to stock is you can be on throttle much sooner and longer. You can better control balance with the throttle. Took me a little time to get used to it because you have to commit staying on throttle to make it benefit you. M3 has good torq so take advantage of it.

Rear spring frequency is high enough with 900, I actually want to go down in rear spring. I want more roll resistance and not increase rear frequency.

[fizzx]

It's Tristan's old diff when he won STU Nationals. 30/90 3 Clutch with custom preloads. Difference to stock is you can be on throttle much sooner and longer. You can better control balance with the throttle. Took me a little time to get used to it because you have to commit staying on throttle to make it benefit you. M3 has good torq so take advantage of it.

Rear spring frequency is high enough with 900, I actually want to go down in rear spring. I want more roll resistance and not increase rear frequency.

Interesting note on the diff. thanks.

I'm seeing a number of threads saying poly in the RTAB is a no-no as it will lead to binding ... and to rather go with limiters and HD rubber bushings.

[Fair]

Terry - with your rtab limiters, do you have to adjust for preload or can you just pop them in and go like poly?

Poly?! In the RTAB bushing?????

I'm seeing a number of threads saying poly in the RTAB is a no-no as it will lead to binding ... and to rather go with limiters and HD rubber bushings.

Yea, poly does NOT work in a dual-axis pivot bushing location like the RTAB.



Stick with OEM rubber + limiters or go spherical (*not legal for ST), otherwise you will add bind in that joint, which makes for crazy unpredictable oversteer.

Yea yea yea, some racers do poly RTABs anyway, but honestly some people wouldn't know an ill handling car if it drove over their head.



As for pre-load, its not an issue with our limiters. We use a fairly slippery material "called ultra high molecular weight polyethylene" (UMHW) which is self lubricating, to remove the chances of binding or preload on the bushing. Slap 'em in and go.



Its kind of a b!tch to machine this stuff, and it costs way more than Delrin or aluminum, but its the right material for this limiter/bushing location.

Terry, do any long tubes currently produced retain the air injection? I was lucky enough to score a BNIB & local set of Turner Shorties a few weeks ago. The install has been...fun.

Dunno, but I doubt it. I've seen people go to great lengths to ADD the air injection tubes to things like Euro M3 headers and use them in Street Touring E36 cars.

[fizzx]

Stick with OEM rubber + limiters or go spherical (*not legal for ST), otherwise you will add bind in that joint, which makes for crazy unpredictable oversteer.

As for pre-load, its not an issue with our limiters. We use a fairly slippery material "called ultra high molecular weight polyethylene" (UMHW) which is self lubricating, to remove the chances of binding or preload on the bushing. Slap 'em in and go.

Thanks. I have your limiters in my old broken down e36m3, but didn't install them myself so wasn't sure about the preload stuff.

[fizzx]

Offset vs standard FCABs? Looking at the condor UHMW FCABs. I've run offset treehouse racing ones for years, but not technically legal since not the correct bushing to metal ratio. I do get tire rub in the front even with rolled fenders and liners removed so standard position would be nice to eliminate any possible rubbing. Just not sure on an autox course if the added caster from offset is actually that helpful, but have no experience to say one way or the other.

[Crustashio]

I run centered. I have a lot of trouble with fender liners on the passenger side and 255/40/17 even then.

edit: Huh, I did not realize you could modify fender liners in ST. I basically cut out the front half of the liner on the passenger side.

[fizzx]

I run centered. I have a lot of trouble with fender liners on the passenger side and 255/40/17 even then.

edit: Huh, I did not realize you could modify fender liners in ST. I basically cut out the front half of the liner on the passenger side.

I didn't check if it's legal, but locally no body has cared thus far. If you find out for sure via ruleset let me know!

[fizzx]

I'll also mention that I had to give up on RE71's after waiting almost 3 months ... and went with 255/40-17 Nexan SURG4's. They aren't quite as good as the 71's, but locally I've done very well with them ... and they were in stock and reasonably priced :-)

[Crustashio]

14.2.E

Fenders may not be cut or flared but the inside lip may be rolled to gain additional tire clearance. (The outer fender contour may not be changed.) Plastic and rubber wheel well splash shields may be modified for tire clearance and to accommodate a rolled inside fender lip. The modifications may serve no other purpose (e.g., air intake, brake ducts, etc). No other changes to the standard fenders or wheel wells are permitted.

So a full removal is technically illegal but you'd probably only get called for that at a national level event. I had a weird situation where one side has zero issue and the other side kept cracking and ripping. I also have the MM undertray though which is probably considered an illegal mod. But the factory one failed completely and replacement was a lot of money.

[sbudshaw]

Thanks for the build break down, I'm thinking of running my 95 M3 at some local events here in Hawaii, but also have a 94 325i project (both subframes out) that I plan to run in stx as well once I return to Vegas. Excited to hear how to car holds up against those s2000s especially with the Nexens. I have some 255 40 17s Federal 595 Rs-RR for the 325i in Vegas and might grab a set for the M3 over here. Will try to provide some insight on an Str breakdown and results (at a local SCCA level) for a little more budget oriented college student build like mine in such a challenging place like Hawaii. Currently have Bilstein sports with flipped top hats (struts don't feel blown), H&R springs with unknown mileage and Turner rear arms. Thinking of going for a:

30mm front adjustable front bar
RTAB limiters
DSSR + Delrin shifter bushings
oil pan baffle? and pump secure nut
10.9 grade front diff bolt (bimmerworld)
Hawk HP +
Supersprint axle back (picked up second hand locally)
delrin trans mounts and offset FCABs
Nardi steering wheel and works bell extender (I'm a taller dude)
driver bucket seat
Kosei K1s 8.5," I know, (they are locally available second hand) but will try a 245 re71 or rs-rr to see how I can hold up

Any input on best ways to disperse limited funds would be awesome!