Wanted: suspension advice...

[jamiholzbach]

Alright you track guru's I've lowered my e30 with GC's, now how do I make it handle? I'm interested in toe set up for a slammed street car/daily driver.
So, please come on and share the knowledge:D

[jlevie]

Step one is to corner balance the car. You don't say what spring rates, but you want more more camber in the front and in the rear and set zero to 1/16" toe out in front and 1/16 toe in in the rear. How much camber to run will be a function the tires and the wear rate you can tolerate. For street tires, try 2.5-3 deg in front and 2-2.5deg in the rear. Race tires will like 3.5 deg front and 3 deg rear.

If you haven't already done so, swap the sways to 19/22mm. weld in reinforcements for the rear sway pickup points and weld in the IE rear camber/toe adjusters.

[F34R]

I love how you gave a complete suspension mod list to help us help you.

For my track setup I and using valved Koni GC spec inserts for the coils. e28 race camber plates and rear toe and camber weld in correction. I took it to a shop that uses an on wheel alignment, cost 60.00 and my e30 is perfect at all 4 corners.

So let us know what you're using, even down to the bushings. They all play a part in suspension/road feedback.
Springs rates, Inserts, camber plates?, bushings replaced? wheel size and tires being used?

In my links below is my build thread, I built the car for track first and somewhat daily use second. It is one of the most over hauled suspensions on the forums. Complete rebuild of everything with only performance in mind. Can give you ideas and show the work done to the rear subframe and front towers for the e28 plates.

Since you are just a street car you can do the IE rear kit to fix the camber ware and allow better traction. Really cannot help out more without knowing what you have done to the car.

[jamiholzbach]

Alright then...

When I posted I was more interested in front end alignment (toe) than anything, and once again Mr. Levie has come through. as for my setup? Currently, I'm doing a low budget build. I've got Ground Control coilovers on Bilstein shocks, specifically rear sports, and iX fronts with shortened housings. As for spring rates I'd have to call GC and see what they sent me, but I imagine they are the softest springs for the E30 (again, daily driver that will probably never see a track). I have Suspension Techniques sway bars in the standard 22/19 set up, and yes I learned the hard way about rear mount reinforcement as the rear bar is currently off until I weld said reinforcements in place.

[Bavarian3]

I wouldn't worry about setup. Just go out there and gain seat time (in whatever you are using the car for).

[e30bulldog]

The best thing to do is get some seat time, but another good piece of information is that you need to know what your car is doing and what can you do to correct it. Listening to someone elses setup may be helpful but can be un helpful.

There are a few things to consider when tuning a suspension:

body roll (this is steady state handling, and it is controlled directly by the springs)
under steer/ over steer: this is honestly complicated... these are all controlled by your dampeners (shocks/struts), rebound/compression can control how your car enters/exits a turn. I usually like a car to plant hard on exit, and loos under breaking. my car honestly pushes in exit it plants so hard.
turn in can be controlled by the alignment (camber/toe), BMW uses a McPherson strut and they loose alot of camber (I run around -4 in the front) and I honestly need more (the amount of camber you use is also dictated by how stiff your tires are). The more toe out you run in the front the more bite you will have on turn in (you can go too far on this) for a street car I would run no more that a 1/16 out net in the front.

The rear of an e30 is bonkers due to its trailing arm design. Under breaking you gain toe out in the rear (or less toe in) which will cause the rear to be unstable (i use this to my advantage to rotate the car on corner entry); the opposite affect is experienced durring acceleration. This reaction can be controlled by the springs, the more rear travel you have the more dynamic to you have.

And lastly caster just increases stability (I run as much as I can)