Quote:
Originally Posted by CorruptCommie
Mr. Bimmerworld on the E46 chassis spring rate:
http://www.m3forum.net/m3forum/showp...3&postcount=15
I would imagine with slicks and aero you should be running higher spring rate, not lower, especially since the E90 platform is heavier.
Shock companies like TC Kline and JRZ that say you should run soft springs, to me, sounds like they are selling their packages as street/track. |
The E46 probably wants more spring up front because it's a simple Mcstrut and has worse geometry than the E9x (seems like people tend to settle on a pretty big front bar on the E46 too), the best way to fix a crap suspension setup is to not let it move, see eg World Challenge RSX's with 2000lb springs in the back. The E46 rear suspension is also different from the E9x, motion ratio on the spring is about the same, but there's no huge RTAB/upright combo etc. on the E9x, the E9x has an additional degree of freedom with that bushing at the bottom of its RTA attached to the upright, iirc it allows some toe-in on compression that the E46 doesn't, or vice versa, I saw a toe/camber curve comparison of the rear a long time ago when these things came out and can't find it, mygoogle fu is weak. So I think you have to take E46 setups with a grain of salt when making the transfer. I'd love to hear James come in here and tell me how wrong I am though, because I'm just a guy on the internet and he's lived it with this chassis
Besides there's no one "right" spring for a car, we just usually stick with whatever we have and tune with the remaining tools accordingly, rather than spend an hour swapping springs when it gets cloudy, because amateurs.
If TCK and JRZ are recommending the softest spring that keeps the suspension from getting out of its happy place, it's not because they're selling something for street cars, it's because that's a pretty well-settled means to arrive at a suspension that maximizes mechanical grip
That said, I don't think dogbone has reached the end of the line on testing stiffer springs with his setup, but I wouldn't mess up a good thing if I were him either
