Bilstein Sport with Coilover question

[kilgojr]

I have looked around and searched through the bullshit on the forum, but I just can't seem to find what I am looking for, and so I am going to ask for some assistance.

I am building an e30 to run Street Modified in SCCA (autocross and time trial). As of right now I am not going to be spending 3000.00+ on an AST/Hyperco or Moton suspension system, there is still too much learning that I need to work on behind the wheel. However, I am planning to put the GC coilover system on the car; but I am wondering about spring rates. I am running the UUC Swaybarbarian 22/19 Sway bars. I will be running a 225 tire on a 7.5 inch rim. I have a brand new set of Bilstein Sports that I want to run as dampers for this system. The car will be gutted and caged and more than likely as close to 2300 lbs as I can get it.

What is the the maximum rate I can run on a bilstein before it needs to be revalved, or do I even need to worry about this? Am I even going to come close to maxing out the damper strength on this car with a reasonable spring rate setup? Obviously I can throw a ridiculous spring rate at the car and blow out the dampers, but is my question legitimate?

Thanks for the help, in advance.

[Stephen]

Well ill let others chime in but i believe 350/500 is about tops. Thats what i run anyway.

Ive seen 375/425 on billies too.

[z31maniac]

I would think the rear shocks are good up to ~600. Don't the Spec E30s run H&R Race with Billie Sports. H&R Race are 315/570?????

[Bishop]

For SM you probably won't get high enough spring rates to work with the Billies. I'm running 400/700 with the custom e30 valved Koni's from GC and I love it

[Hellabad]

call me and I'll explain.

But here is the short, but still complicated version.

there are two worlds. the perfect world and the real world.

The perfect world is where you choose a spring to match a shock, or vice versa and it works because they match. Everybody is happy puppy rainbows.

But in the real world, the damping and the rate may "match", but there are other things that are working against you.

On an e30 with Bilsteins, you have the spectre of bottoming out, always hanging around. It wont go away. You have to minimize it.

In order to make the car go faster, you have to do have two wrongs make a right. If you go too high on the springs, the struts won't dampen correctly, HOWEVER, the car won't be bottoming out which would be worse.

So an e30 with the wrong springs will be FASTER than a car with the right springs.

There is an analogy regarding wimmens in here somewhere, but I will leave that to someone else.


Jay from GC 530 677 8600

[Bishop]

call me and I'll explain.

But here is the short, but still complicated version.

there are two worlds. the perfect world and the real world.

The perfect world is where you choose a spring to match a shock, or vice versa and it works because they match.

But in the real world, the damping and the rate may "match", but there are other things that are working against you.

On an e30 with Bilsteins, you have the spectre of bottoming always hanging around. It wont go away. You have to minimize it.

In order to make the car go faster, you have to do have two wrongs make a right. If you go too high on the springs, the struts won't dampen correctly, HOWEVER, the car won't be bottoming out which would be worse.

So an e30 with the wrong springs will be FASTER than a car with the right springs.

There is an analogy regarding wimmens in here somewhere, but I will leave that to someone else.

Woops, edited because you edited.

[Hellabad]

Woops, edited because you edited.

Yeah, I realized I should put my number so the guy can actually call.

Jay from GC 530 677 8600

[2002maniac]

I'd suggest something like 500/750

[Bishop]

I agree... My 400/700 is fine for daily driving. Can be a tad harsh depending on the road conditions, but I would want higher spring rates if I knew the surface was going to be more optimal.

Now, correct me if I'm wrong, because this is just a guess, but if you go too high with your rates would this hurt you by causing the car to be a tad unpredictable? I was thinking high rates on a track may be good because it's usually smooth, fluid movements. But with autocross, the higher rates may upset the car with quick, jerky direction changes

[Jean]

I had 500/650 with my bilstein sports, probably can't go much higher than that though. Maybe think about using Koni inserts instead?

[z31maniac]

I'd suggest something like 500/750

We shall see. Jay spec'd 550/750 for my swap car with 22/19 UUC bars.

[robmespeedy]

i have 800/1000, i know my billies need to be revalved.
anybody know how much it cost to revalve them?

[Wh33lhop]

i have 800/1000, i know my billies need to be revalved.
anybody know how much it cost to revalve them?

From what I remember, Bilsteins are intrinsically simple and tend to cost less than the price of a shock for a revalve.

And yes, that is cheap.

[robmespeedy]

From what I remember, Bilsteins are intrinsically simple and tend to cost less than the price of a shock for a revalve.

And yes, that is cheap.

any suggestions where i can get them done "cheap"?

[Wh33lhop]

Nope.

I have no intentions of revalving mine--when I want a real spring rate, I will get real suspension.