View Full Version : E30 coil-over suspensions

05-22-2002, 09:11 AM
For a E30 325is, what are the typical spring sizes (not rates)that are used for most aftermarket coil-over setups (ground control, etc)?
Are the springs 2.5" ID, 2.25" ID or other? What about spring lengths ? If anyone has this info handy for the coil-over front & the adjustable rear, it would be much appreciated.
Chris Reinke

05-22-2002, 02:24 PM
2.5" ID x 6" front
2.25" id x 5" rear
That's what I have on my Ground Control coil-overs. That's what they recommend.

Bruce Shafer
05-22-2002, 06:22 PM
I had the same on my E30. The springs, shocks, and hardware were also from GC, but the spring rates were nowhere near what they recommended.

05-22-2002, 06:49 PM
Did GC recommend 550# front and 650# rear? That's what they told and sold me last year. This year I'm trying 450 front and 550 rear. Jay at GC says that any softer in the rear will bottom out the shocks.

05-22-2002, 09:16 PM
I run 600 front 700 rear and need to go stiffer in the front.

Any less than 700 rear and the shocks will bottom out. I have checked this many times with the tie wrap on the shock pistion method.

You see on the rear e30 the coil is half way up the trailing arm so you only get a percentage of what the spring weight is at the wheel.

05-22-2002, 10:22 PM
Where do you race? You must race on some really nice surfaces.

Bruce Shafer
05-23-2002, 08:43 AM
Yes, GC recommended that setup. Right from the start I could tell that wasn't right (at least for my lack of driving style). After going through about 8 sets of springs I ended up with 850 front and either 600 or 650 rear (depending on whether I was running a locked or LSD differential).

Also the rear shocks were bottoming out at first. I ran Koni single adjustables. Fortunately there was a shorter version of the shock that I ended up buying. Made a huge difference in handling and lap times. Wouldn't have believed it if I hadn't seen it for myself.

I should have my new E36 out in two weeks at Sebring. I just hope it is as much fun as the E30 was. I sure miss that car.

05-23-2002, 03:06 PM
Is everyone here matching the valving on their shocks to the rates on their springs? A 'regular' set of Konis would never be able to control a set of 700+ lb. springs...


chuck baader
05-23-2002, 03:11 PM
djsmith--shame on you for buying shocks that are too long... 550 will work great if the shock length is adjusted to match. my .02

Chuck Baader