Cooper993

OK, I know this is a very subjective request, but I'd like to set-up my S4 so that it is as close as possible to the stock E36 M3 I used to have. Although the M3 had a lot of problems, it had, IMHO, an excellent suspension for aggressive street; minimal body roll, handled well, all without too much firmness/harshness.

Can anyone recommend what I could do on the S4 to make it ride the same?

I am not interested in full "race" options. Maybe a sway bar, H&R springs and Bilstein shocks. What do you think?

TIA

S4mig@PEB tuning

You want to play you have to pay. You'd need to buy stasis tracksports at the least.

Cooper993

My 911 has 450 front 600 rear springs and they are very firm. The Stasis starts at 450 and goes to 1000. I think that is way higher than what the M3 would have from the factory.

Let me know if I am mistaken.

Thanks

S4mig@PEB tuning

It all depends on what you feel is harsh. I've rode and driven a S4 with tracksports at 700/800 rates and found it to be perfectly comfortable. I am also the kind of guy willing to try 900/1000 though.

Polar

tires plays a huge part on the ride quality with the stasis setup

RKA

Best bet...call STaSIS, and tell them you want your car to handle like an E36 M3. That's not to say your car will handle like that, but it gives them a good (and common) benchmark. They can tell you what you should be looking at, what it's going to cost you, and what your realistic expectations should be as compared to your benchmark.

You'll find STaSIS a really good company to do business with.

mpwolf

That's not going to do it, call Stasis, get TrackSports.

JBirdS4

my bilstein/h&r setup is quite a bit softer than an e36

ryans4

...You should first convert all the spring rates to wheel rates, then factor that wheel rate against the corner rate of the vehicle.

So for example, a B5 Audi Front suspension is a multi-link, with a motion ratio of about .7:1. So a 600lb. spring results in about a 420lb. wheel rate.

An M3 or 9111 with it's McPherson front strut is closer to 1:1 motion ratio, so a 450lb. spring rate results in a 450lb. wheel rate.

Now you take the corner weights, a B5 S4 is about 1100lbs. per front corner, an M3 is about 3100lbs. at 50/50, so figure about 775lbs. per front corner. A 911 is about 625lbs. or thereabouts (3100lbs. at 40/60). THESE ARE VERY GENERIC NUMBERS, but you get the idea.

So now you can compare:

B5 S4 - 420lb. Wheel Rate - 1100lb. Corner Weight
911 - 450lb. Wheel Rate - 625lb. Corner Weight
E36 M3 - 450lb. Wheel Rate - 775lb. Corner Weight

Now you find that the 600lb. front spring on an S4 is actually not that aggressive.

Of course, you could put identical wheel rates to your 911 on an S4, but that doesn't mean it's perfect since weight distribution and weight is a huge concern.

It's tough to compare cars with such different chassis setups, the S4's has weight and weight distribution against it, and that makes setup more difficult than lighter 50/50 cars like an M3.

Cooper993

That's a great explanation. Thanks!