Re: M3 springs? (long)

["I.L. Eberhart" <eberhart@xxxxxxx>]

Hi Lane,

you asked about the difference switching to an M3 suspension would have in
stiffness, comfort and height.
First, your subject line says M3 springs, don't forget that your struts,
shocks, wheels and tires are part of the suspension. So, an M3 suspension
also consists of different struts, shocks and 17" wheels with the
appropriate tires for it to perform as designed. Changing the springs only
will not give you the performance of an M3.
Changing to stiffer springs only will shorten the life of your shocks and
struts causing you to replace them at an additional labor cost. By changing
springs, shocks and struts at the same time, you save labor (or time if you
do it yourself).

You did not mention what your expectations were. If you're trying to get a
stiffer suspension, there are stiffer setups available (H&R Springs with
Koni Adjustables on full firm are one choice). If you want a more
comfortable ride there probably isn't an aftermarket setup that will offer
this (to my knowledge), however using replacement OEM parts may yield you a
stiffer and more comfortable ride (your current springs should have 3 or 4
years of use on them and returning to factory new should be noticeable). If
you want a lower ride height, there are many choices available that will
greatly decrease the ride height (Eibach Sportline Springs are one example).
Be warned, altering the suspension on your car will make it less predictable. 

The best way to enhance the handling of your car is to modify the "Nut
Behind The Wheel". Doing some autocrossing and driving schools will yield
much more benefit than any suspension upgrade. Plus, you'll have an upgrade
you can put into any and every car you drive, experience. Then, if you
decide to upgrade the suspension, you'll have a better idea of what's
needed and you'll be able to take better advantage of a stiffer, lowered
suspension. Before doing any suspension modification, you might want to
drive a few modified cars. I'll bet the guys in your chapter would be happy
to take you for a ride, or let you drive their cars. 

By the way, my car has Eibach ProKit springs, Bilstein shocks and struts,
Dinan camber plates, Dinan sway bars, the lower X brace, a Racing Dynamics
strut brace, an Active Autowerke rear shock tower brace, and I'll still get
wupped by someone with more experience in a stock 325. Experience is key to
performance, not just performance parts. 

- - Chip Eberhart
Windy City Chapter
BMW CCA #144492
NSSCC
Team Frantic Racing