I should add the condition of street tires to the numbers I gave previously. A friend of mine is running 8xx front, 7xx rear springs on his auto-x car with street tires. It seems to me that many of the road course guys on street tires are in the 6xx range.

When you toss in R-comps, going to a higher spring rate is a good idea.

 

So I cannot run front aero as it would put my car in NASA TTB when i eventually move on to TT. I would not be competitive and want to start in TTC.

The point is, when running a wing and no compensating front downforce, how much more even should spring rates be? Seems like they should be a lot closer to even than the stock F/R ratio if not even. Don't the KWv3 and CS have even F/R spring rates?

 

Matt, I did battle understeer initially. Either I have adapted my driving style to the setup, changed the settings and alignment to compensate, or both. At one point I did run 500F/550R. I do not remember it being hard to handle, but I did have the Gendron bar.

 

This is some great reading when choosing the springs. You may end up changing them out so get used to selling and buying springs. Used isn't a bad idea either.

http://www.optimumg.com/OptimumGWebSite/Do..._Tech_Tip_1.pdf

If you run a higher frequency the car will settle flat which may be a good thing depending on how rough the surface is. Also, the good news is you can swap the springs front to back if you want to try a higher front frequency.

To really pull this off you will need a front bar with a wide range of adjustment and a good alignment shop. A custom rear bar may also be a good idea.

I am running even springs right now because that is what my shocks came with. Once I get through this autocross season, I may play a bit more.

 

Matt,


You are going to be limited by what springs the OTS Konis can handle. I have always heard the limit described as around 500lbs.


I run a similar setup to you (225/255 NT01, CT race bar, 571/571 springs, GTC-200) and I have some understeer. Not terrible but noticeable present. Going to a 255 nonstaggered setup would be the ticket and I will switch over as soon as I burn up these tires. I am running an AP2 and you have an AP1 so bumpsteer will be an issue with you?

I would try spring rates at the upper level of what your OTS Konis can handle (450-500lb range). Perhaps a little lower in the rear.

 

This is the real point- the shock limits.

 

Ok, I called Koni North America and talked to the tech support guy there. He said the following:

1. There is no ideal "max" spring rate for a shock, including the Koni Sport (we all knew this)

2. The valving is pretty good on these, but the high speed valving is a little softer than a real Koni race shock

3. Running too high of a spring rate will cause the car to feel underdamped, not cause the shock to blow out

4. Definitely keep the rate under 600#, and ideally around 500# or a little less.

So basically the conventional wisdom on this board was correct. Thanks all for your info.