Originally posted by ROB89M3
I'm gonna be getting Coilovers from GC(should've had them already) but I keep on getting held back because of trying to decide on which spring rates are good for street/track.I'm looking at getting 750lb rear and 500lb front.Is this too harsh or is it a good rate? I will be using Bilstein "sport" shocks with these coilovers.
I drove an M3 with 600lb rear and 500lb front.It felt fine.But,someone keeps telling me that this setup is not balanced for the car..I don't want to upset the handling of my car and I don't want the car to be bone -jarring -suspension -breaking STIFF!!
YOUR INPUT ON THIS IS MUCH APPRECIATED!
I'm curious as to how you're planning on running 60 mm springs (from a coilover) with a set of Bilstein Sport shocks?
The front shocks (actually, a Macpherson strut) use a 4.5-5 inch spring, and not the 2.5 inch spring used on a set of coilovers.
Coilovers are a system you can't get a *mixed and matched* setup like that.
If you want the 60 mm (2.5 inches roughly) springs, then you need to purchase a set of coilovers for the car, which are going to include springs with them, carefully matched to the valving rate of the shocks.
I'm going to ask a couple of questions here, and don't take this the wrong way, but look at it from a reality perspective.
How many driving schools have you actually done Rob? The suspension on the E30 M3 is fairly decent already, so I would suggest saving the $2000 for a set of coilovers and do as many schools as you can this year. The slowest part of ANY car is the driver.
This way, you don't have to compromise on street performance / track performance. You'll still get the ride you're used to on the street, and so what if a bunch of people pass you on the track? You're only in either the C group or B group anyway (I saw the list, but I haven't memorized where everybody is...).
As to spring rates, it all depends on your level of tolerance.
I'm running 650 lb springs front and 900 lbs springs rear, but my car is essentially a go-kart now. It's stiff enough that I figure I can tell the difference between a nickel and a dime when I run over it with my car....
500 front and 750 rear *might* be too stiff for your tastes, as your car is significantly lighter than mine. Chris is running 400 lb fronts and 600 lb rears, and his car is essentially a go-kart as well.
A final factor to consider. The stiffer your suspension, the more likely you are to bend a rim if you're driving your car around the wonderful Toronto streets. Every pothole you hit has a chance to bend something....
Personally, since your car is a daily driver, and not a dedicated track car, I'd look at something like H&R Coilovers. They are more *street friendly*, but still stiff enough to improve performance at the track.