3.8 911 help. Part 1 - suspensions
 

Hi all,

I am putting down the details for my 3.8 RS project. Everything is a clean sheet at this point so I would love to hear your inputs on a series of choices that I will have to make.

What I have decided so far is that I am going to swap my 3.2 with a 3.6 Varioram. Will then have the 3.6 converted to 3.8 RS specs.
Also the car will receive 930 style flares. Everyting else is up in the air.

So suspensions. I can upgrade the torsion bars and the shocks or go coil over. Money is a secondary factor here..
I want to build a very fun car... The car will still be a street car, but with good track capabilities.

Are coil-overs overkill for a street car? Should I just stick to upgrading the shocks and torsion bars?

The primary advantage of coils is they allow you to go with stiffer spring rates than you can get with torsion bars. Since you will be using the car on the street, you won't want springs that stiff anyway.

The other big advantage is that you can change springs with relative ease. This appeals to race teams that swap springs trackside to tune the suspension to a given track. If you don't plan to do this, it's not a real advantage.

Coils also raise the center of gravity (a negative) and require re-inforcement of the rear shock towers.

If you decide to get competitive, you will find coils may force you into a higher class. And unless you build the whole car out to that classes limits, your car will be outclassed.

For street driven and dual purpose cars, the only thing coils really gets you is bragging rights. Torsion bars work well and are the right choice for most cars.

I agree t-bars are fine for any street use even w/ some limited track use, generally set em up once then forget them until the bushes compress(or squeek)

Very stiff springs need a very smooth paved surface to be effective, which is why -- this being a nation of mostly crummy roads -- they don't make sense for street use.

I'd agree that torsions can provide all the spring rate you can make good use of for street (and occasional track) use.

Jack

i am looking to covert to widebody (930 flares) and use 17' lindsay racing fuchs. If I remember correctly you are not using spacers on your car. What did you do? Dig u get Turbo trailing arms? Or did you have the wheels made so that they would just fit with no spacers? Thx

Two others:

1. Can't you lose some wt. by going with coil-overs?

2. Coil springs can be made progressive - that may or may not be a benefit, depending on your driving style/experience.

I agree there is no real reason to do this on a street car.

I actually have 1-inch spacers in the back. The decision was made that way because we wanted to play it safe with fitment issues, and my (non-Turbo) trailing arms were going to have their mounting points moved with Smart Racing camber boxes. We were building the car in 12 weeks, and weren't sure where the hubs would end up, exactly. Plus, I wanted to be able to run either 315's or bigger 335/345 tires in the back. I can do this my running a smaller spacer, now, without having the 315's look like they're tucked way inside the flare.

With wide barrels, there's also something to be said for keeping the center piece fairly close to the physical center of the barrel. Without the spacer, by Fuchs center would be another inch toward the inside.

You know, Lindsey should make a 'testing wheel' with a Fuchs center that can be moved inside the barrel (with a few different-width barrels, too), so that they can ship it to customers, and then have the customer test fit to see what the ideal backspacing would be for their particular setup.

Great idea.

A friend of mine is looking at big brake kits for his M3. One company sent him a 1:1 paper template to mount up on the wheel to verify fitment. Smart.