Suggestions needed: Spring rates/no swaybars for 318is

[BrandC]

I'm doing a bit of probing before I buy the Ground Control/Koni coilover kit. I do NOT want to run aftermarket swaybars, I want to control bodyroll with high spring rates. This setup is meant for track-duty, but it will see street time too.

What rates do you guys suggest? I've seen 600f/650r for a track setup and the owner really liked it at his first track day (I forget your SN, I'm new on here!). TIA, cheers!

-Brandon

[e9nine]

Dunno if it's me you're referring to but shock and spring combos are somewhat of a personal choice. It also depends on your driving style etc after a certain point. Some don't push their cars hard - others brake late - some left foot brake - others over-do everything....

Some people assume they can daily these rates. Many variables come to play and I don't claim to be the guru of suspension set up. I think Alex S even runs 500/500 or so depending on the surface he's on.

I went through about 3 different rates before settling with 600/650 and then did the swaybar delete and liked it. You cannot totally eliminate body roll on a car that you will drive on the street. You might think your set up is roll-free till you see pics of your car being driven hard or see someone else driving your car.

Personal prefence

Here's pics of 600/650 under different turning conditions with 205-50-15 Falken tires in a 318iS. If you're interested I'll send you the other pics of my car from the HPDE when I get the CD in. Send me a PM

[D. Clay]

Most teams change springs and bars for each track. Smooth and bumpy tracks call for different springs and corresponding bars. You have to keep the tire in contact with the pavement. Hard to do with 600# springs in a 2500# car. It'll hop, pump down on the shocks, and  skate on a washboard surface. Then you need softer springs and stiffer bars. If the track is really smooth you can run way stiff with springs and minimal bars. My point is that there is no optimal setup for a car. You are tuning the chassis to the track and to the driver. Drivers are as big a variable as cars in this case.
"I do NOT want to run aftermarket swaybars, I want to control bodyroll with high spring rates. This setup is meant for track-duty, but it will see street time too."
The above statement severely limits your options. Bars are a part of car setup for a reason - just like shocks, front/rear and left/right wheel weights, cross weight, gears, tire compounds, suspension settings, and track temperature to list a few.

[e9nine]

Thanks for the input D. Clay. Can a mod merge this thread with the other one he posted in the suspension section or so.

For dual purpose cars as much as you will hate to use sways- the are more civil to live with and the infamous phrase "personal preference" pops up again. To each driver and their own desires. Whatever will make you utilize your skill and cars ability best is what's optimal. When you start to get consistent times based on your settings/configuration its obviously the best feedback you can get. It take a lot of resources and time to get the perfect set up. I am not even aiming for that this year. Just trying to get the nut behind the wheel disciplined before shifting focus to the petty variables I can tweak on the car. (I know I can contradict myself at times with feedback but in a nut shell that's the best way to approach this IMO)

[silverblades181]

why wouldn't you want sway bars?

[BrandC]

I don't like swaybars because they react only one way, side to side. I like all four of my corners to have more independent suspension travel from each other. It's just a matter of what you want the car to do. Besides, less money to spend on parts. I'd rather fork over extra $400 for better tires or track days.

[BrandC]

E9nine is right, hopefully mods can merge these threads. I also agree that I should be spending more time behind the wheel/track time and then tune from there. Maybe I can start out with milder rates and just upgrade as my skills build.

I may just have to add swaybars to the picture, who knows. I will be learning more about the car as well, but I was just wondering what rates people would suggest. I've read the R3Vlimited "post your track setup" thread, but it's not that big of a help.

[st600r]

I have an '84 E30 318is SUPERCHARGED, 160HP on the ground.  It was street driven with ground control springs 375 front/450 rear. I really liked it for the street. And yes, it was probably a little soft up front.  BUT, as many people have pointed out, as conditions change, so should your springs.  Not very practical on a street car.  My advise is to err on the side of soft.  I have since made the car a track car, and use 450/450 springs.  I am considering going to 550 in the front, but this may require me to re-install the rear swya bar. I do not use a rear bar on the 450/450 setup, and the car is REALLY hooked up, and yes it does roll a little bit. REMEMBER, err on the side of SOFT. It works in more situations than HARD does.  Good luck! STEVE