I've done 800/600 and Yom has 850/650. What do you want to know?

 

does it feel balanced or is it more on the pushy or oversteer side? With 900 front and 700 rear my car feels good but I find myself liking no compression or very little on my shock settings. I feel I would have more grip with a 800f/650r set-up. Plus I could use more of my shock setting before the car would start to loose grip. What other springs have you tried and what made you settle with that spring. Basicly any insite you wanna give on that spring range would be great. If you wanna keep your finding to yourself I respect that also.

I've tried 700f/700r, Realized I wanted more spring in the front. So I moved on to 900f/700r Car feel balanced but all together feels it might be alittle on the stiff side. So Now I'm thinking 800-850f/600-650r

heres a video from today-
http://www.vimeo.com/26243375

the car works great *but* it might be alittle on the stiff side for the lots I run on 90% of the time.

edit- for video

 

Josh,

It's nice to see a guy put a lot of effort into his car setup. But what you are trying to do with spreadsheets, formulas, and thoughts of "might be too stiff" really are not what will help you pick spring and sway bars.

What you should do, is pick springs and sways based on how you want the car to handle according to your grip levels.

Since I live by the nationals site I am planning the car around the grip I get there. This will be a compromise of sorts, because if I go to a less grippy lot, I will not be as fast as I could with my LAP settings. But worst case, I can bring the front sway bar down or change the tire/shock settings. So, tune for the most grip, but have a backup plan with your swaybar, if the grip level is down for rain or a different surface.

For instance, earlier this year I had 800/600 springs, but added more front negative camber. This changed my front grip dramatically. I had to remove the rear swaybar, change the shock settings and tire pressures to keep the car from oversteering any time I turned the wheel. For the next event I plan on trying out 900/600 and more rear toe in to see if those changes will let me toss the car around more. I may get 1000 lb springs if this is not enough.

Tune for grip, not for a magical 15% split in spring rate, or what your spreadsheet says. For me, I cannot afford a new sway bar, so I'm limited to spring changes. I won't go lower than 600 in the rear, since this limits how low I can go and how much shock clearance I have for daily driving. I probably should go to 700 in the rear, but I don't have any more time to test out more spring combos, and I need more rear grip.

 

I understand what your saying. I said the hell with the spread sheet on front bar settings and went back to my 4/6 on solid bar setting. My reasoning to consider a softer front/rear spring is I'm finding myself using very little compression. If I take out alittle spring, I could now use alittle more compression. Good luck with anything over 900. 900 feels great but gives up alittle on low grip lots. Even at Blytheville I was only using 3 clicks of high speed compression (all around) and 3 clicks of low speed compression in the front, with 2 clicks in the rear. Were talking about shocks that have a 14 click range. Rebound is money! I set it to 65% critical and it's never felt better. It clearly worked today if you look at our local times.

By taking out alittle spring I could add a click or two and let the shocks work like they are suppose to.


Edit- BTW the "fast" guys at blytheville had springs in the 700-850 front and 500-650 rear. Only being able to use 3/14 clicks of compression on a very grippy lot tell me my car is to stiff. Anything over 3 clicks it just got slicker. Would you agree?

Thanks for the input though, good luck on your tuning!

 

Did you try adding more rear camber first?

 

Rear camber is within .5 of the front, and after discussions with my co-driver, he thinks it won't make much difference.

BTW, before the camber change, I had equal front to rear camber.

 

Not using compression is a byproduct of having stiffer springs, you don't need as much when they are stiffer, that is their relationship. I have the same issue, with 12 clicks and only using the first 3 or 4. This is not a reason to use softer springs.

What front bar are the "fast guys" using using? That data will help you decide what to do. I don't have the stiffest front bar, so I have to compensate with stiffer springs.

 

Some of the "fast" guys are on a huge bars. The monster (1.375") bar, setting 4-6/6 usually. That wouldn't work with my driving style. Thats to pushy for me. I like my current bar feel, might go a click or 2 stiffer if I drop the spring rate 100lbs, just to test. I like a balanced car but not a pushy one. I tend to over drive the car alot and I can't drive a pushy car.

Thanks for the input though. If I make a spring change it will be a "over the winter" thing.

 

while at the denver pro solo, I organized a weigh in between Thorne s CR, an Ap1, and Ap2. One result was as expected, one was a but surprising. I need some time to list the mods of each car, and I can't do that here at the airport on my phone, so I'll reveal the results when I have some down time. Hmmmm, I wonder if there are any cheap CR s for sale...

 

DUUUUDE, do NOT tune your car settings based on that newly sealed asphalt lot! Well... Unless you are going to go to more events on those conditions, then go ahead... But, if you are wanting to go to national level events that have speed and grip, tune for that and just adjust for the slicker lots the best you can. Obviously, just your shock adjustments were good enough for today.

Matt, I figured out why my car was pushing so much at Toledo. I thought all four corners' compression settings were at 1 click of 12 (almost full soft), but the front was actually at 6 of 12. With today's even being on freshly sealed asphalt, I was willing to do anything that was easy to compensate for those conditions and was surprised to see I had so much adjustment up front... oh well, now I know...

-Dave