please help determine spring rate

[lafayette college fsae]

Our car is about 1000lb w/ driver, yup i konw its heavy. We are using hoosier 20.5 X 13 tires w/ a pushrod suspension that gives us an install ratio of 1.225. I was using the millikin design equation and determined some spring rates but the car is too loose. The car is running 200 in fron and 300lb/in in the rear. Can anyone please give me some help on how much more spring rate should be added. I was thinking 400 all around.

[fade]

you might try to booger up the wedge that usually tightens up our cars

[SpdRcr]

is your driver obese?

[B Hise]

what do you mean by loose?

oversteer? bottoming out?

Bryan

[Jersey Tom]

Whoa, 1000 lbs? Do you have a picture of this?

And just for reference, our car is ~600-650lbs with driver, and we're running 300 and 350 lb/in springs

And you're running 13" wide tires?? Or do you mean 20.5 x 7 - 13 or something like that?

[Steve Yao]

'Tight' or 'loose' are usually terms heard from nascar folks.

From the listed spring rates, i'd guess he/she means oversteer. I'd recommend more closely matched spring rates(i.e. stiffer fronts) to get rid of the oversteer and stiffer springs in general for response.

Mind commenting on your track and wheelbase, Lafayatte?