Larry Herman

My head says that you are right, but my RSA was really good in the rain. Soften up the shocks a little and it was really predictable. It had 1400+ lbs springs. Go figure.

onefastviking

What tire did you run with the 1400 lb springs ? ? ?

bobt993

^^^^^ I am running the same setup as Larry. Both are using R6's dry and Hoosier rains for the wet. My rain times do suffer a bit compared to a 900lb spring setup.

Larry Herman

Like Bob said, Hoosier Wets. They were terrific. I have a short video of my car at Road Atlanta in the rain posted on Vimeo. The braking was outstanding.

onefastviking

Have you ever seen or felt any tire issues with that high of a spring rate or do you adjust the pressure up some over normal to offset any issues ?

Larry Herman

None what so ever. I adjusted tire pressures "normally" based on temps and lap times, and the RSA was very gentle on them too. Would get about 20 very competitive heat cycles out of them before they would fall off.

As far as the rain tires, I wound up running them a couple of lbs below what the hot pressures were for my dry R6s and that seemed to give lots of grip. After a sprint and an enduro in the rain, they looked virtually un-worn.

bobt993

+1 on what Larry experienced. Keep in mind there are tenders on that setup that allow .5 inches of travel before you hit the big springs. Very easy on tires. I gathered the track record twice at Summit last year in GTS3 running tires with a dozen or so heat cycles on them. I am tossing tires before they even cord with this setup. Very happy.

mark kibort

exactly. That's why in the GTGP race, my, generally, too soft set up was just right when we started racing in the rain. it makes the car a lot more controlable with low grip, even with the use of street tires, vs DOTs or slicks.
guys with slicks and the much stiffer suspension were having a lot more control problems.

I also was under the impression that with stiffer springs you dont need as much camber, because you dont get the body roll. Im sure this is geometry dependant to a great extent as well.

bobt993

Camber drops off about 1deg with the stiff setup.

onefastviking

The problem I have run into was having too high a spring rate so the tires (DOT's) started deflecting more and caused some over heating tire issues. Maybe it's not an issue as much on shorter sprint races or in climates that are not as hot as we get down here.

bobt993

Actually I can remember one such situation where this does happen. T2 at WG with the massive camber it has did rip up my weighted tire. Summit not a problem and I ran that race in 90deg heat.

Larry Herman

Interesting. I ran my Hoosiers on relatively wide wheels 9s & 10s for their respective sizes (245s & 285s) and fairly hard. I found that the best grip was with pressures in the 38-39 lbs range, but at that point a further increase of one or 2 lbs would cause them to go off, so I usually went for hot pressures of around 37 lbs to give myself some margin.

onefastviking

Ever run in the heat ? Or for longer races ?
How much did your car weigh ? Was it the white RS ?

winders

Larry,

How do those spring rates translate into wheel rates?

Scott

Larry Herman

It was the White RSA and it weighed 2910 with me in it. I don't think that I ever ran in temps much hotter than 90 degrees. The longest that I ran was for 90 minutes. Due to a failure of 4 bolts, I did finish an enduro once with 17 lbs of air in the right rear. Didn't appear to hurt the tire though.