Hello, I am confused on how you guys decide your spring rates for racing do you go on the weight of the car and then decide or to you track test?

 

Talk to people who are running the same car as you.... try to get a baseline, then you'll end up swapping them again probably to what fits you best after a couple weekends on track.

 

what would be a good base line to start with?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Talk to people who are running the same car as you</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by combustion &raquo;</TD></TR><TR><TD CLASS="quote">what would be a good base line to start with?</TD></TR></TABLE>

Higher rates in the rear than in the front. By a lot. I run 600F / 1000R. It rotates quite well this way but is NOT for beginners.

 

If your new to autox or roadracing then i would suggest a way higher spring rates for the rear. I would go for something a little more even. But talk to people with your car and get some specific ideas for your car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by patmcd &raquo;</TD></TR><TR><TD CLASS="quote">If your new to autox or roadracing then i would suggest a way higher spring rates for the rear. I would go for something a little more even. But talk to people with your car and get some specific ideas for your car.</TD></TR></TABLE>

As Karl said, wouldn't that make the rear rotate more easily, thus leading to potential problems with noobs involving oversteer?

 

after going thru my first year of racing with high rear springrates, i regret not just going with the standard 400/600 or something more close to it. my feeling was that i wanted to learn how to drive fast with the fast setup from the start, but its just better to start conservative, theres plenty to learn and can be plenty fast without risking it all to be really fast and not be ready.

 

I will have to agree with Tyson. Since this was my first year on track with a FWD car, I decided to start out relatively conservative. While I knew that Realtime is running 900f/1400r this year on their ITR's, and 800f/1200r in the last few years, I chose a much softer set-up of 450f/550r to start. After a few events, I swapped the rears to get 550f/650r, and moved up the learning curve. I only spun once this year in about 22 track days (rear end came around) on cold tires on a cold day, so I think the choice of rates vs. driving skill was good. Next season I will be putting the 650's up front and moving up the rears slowly while I learn the car. This will require re-valving the shocks. The setup with the rear springs at 1.5 times the front will make the car oversteer more and be harder to drive. Keeping the rates of the front and rear closer to each other gives a slower rotating car, but easier to learn. Having the car rotate faster (stiffer reear springs) allows you to get on the power earlier in the corner since you get the wheels pointing down the straight faster, but you are more likely to spin. Even with a stock motor and this set-up in my ITR, I was plenty fast when running in the most advanced run group in some Porsche events, and I could pass at least half the cars, almost all of which were faster than me in the straights. So start with understeer, and work slowly into a more oversteering car, unless of course you are not paying for any crash damage!

 

As Tyson mentioned you should build up to the ideal setup.

I went from stock =&gt; 560f/336r =&gt; 560f/672r
Even the rear sway bar got thicker with each change: stock =&gt; 22mm =&gt; 23mm =&gt; 22(38)mm

If I had just jumped to 672r from stock I think I would have spent more time backwards then forwards.