MC 968CS

Hi, I am in the process of sorting a new upgraded coil over setup for my 968CS with MO30. It is used mainly for track days, supersprints, motorkhanas.

I am considering a few options, and am finding the spring rates just incredibly different in each. See below.

So, any advice is appreciated..why are the front to rear spring rates just so incredibly different? Some have lower, some have higher rates at the rear than the front. (All come with shocks to match.). Confused.......

Option 1 - Kw Clubsport
Front Spring = 515 lb/sq. in
Rear Spring = 285 lb/sq. in

Option 2 - CROSS Motorsport Setup http://www.cross-na.com/ViewProduct1...lID=116&CarMak
Front Spring = 450 lb/sq. in
Rear Spring = 564 lb/sq. in

Option 3 - Eibach / Bilstein setup
Front Spring = 500 lb/sq. in
Rear Spring = 350 lb/sq. in

thingo

The Cross set up would be without the rear torsion bars, that is why the rear springs are stiffer.
I have the kw's, they were a custom order but they are the same spring rates as you quote.(10f 6r).I'm very happy with them, bought the same brand for my evo.
I wouldn't get too concerned about the spring rates, it is easy to change the springs.My 968 did understeer a bit the last time I was in it, but it drove great, sat very flat.Comfortable on the street as well!

MC 968CS

Thanks Rod, really appreciate the input. I am open to other ideas from anyone re options too,if there are ideas out there.

(Aside - anyone know what is the standard MO30 spring rate setup F/R ?)

thingo

M030 is a lot softer, like 220 f, the rear helper is 70-80, they go much better with stiffer springs,it seems a big jump but the car just becomes more responsive and enjoyable.

968workaholic

Are you going to be running the torsion bars? If not I have had great results with using the bilstein setup. The rear spring rate that you have in your package is a bit too low for a 500 front, a 450 would work better. Again this depends if you are using torsion bars or not.

MC 968CS

Thanks - I was assuming I would run the torsion bars, but am now thinking I need to learn more about what they do!

Jason Judd

Torsion bars are just springs...horizontally oriented, rather than vertically. They all do the same thing.

968workaholic

If you get rid of the torsion bars, it will make it easier to adjust the ride height of the car. Even if you re-index them so the car will sit lower, you are still going to have to screw with the spring plates to get the height where it needs to be. But, if they are re-indexed wrong you will want to pull your hair out because you have to take the whole thing apart again to fix it.

mikew968

Again here are some of the issues:
1. Will you drive on the street? What % of time?
2. Rear T-bars?????
3. street would be 200-300 front and rear
4. compromise: 500 front and 600 rear (no t-bar)
5. Full race: 600 to 900 front and 700-1100 rear

The 968 w/o t-bar needs more spring in the rear to handle well. That may not suit street driving so well!!!!!

MC 968CS

Great, appreciate the input. Here we go to answer your queries Mike 968
1. Street Driven - No - only to and from events really
2. Rear Torsion bar delete - yes now seriously considering it.

I am looking more at your 'Compromise levels' above. Car does track, tarmac rally and motorkhana events.

mikew968

What is a motorkhana?

MC 968CS

Well, this is a mate of mine doing one....though not in a Porsche. http://www.youtube.com/watch?v=qJsFn...eature=related

FYI, this is a V8 Chev powered MG. Over 800m it is slightly slower than a 996GT2 rebodied into a cup car chassis. Only reason it was slower was it spun the wheels till it hit 100+ MPH, or 160 or so km/h. ie: It was catching the Porsche like you just would not believe!