Tire Pressure In The Wet

#1

Ok I have very limited time on a wet track. With rain all day in the forcast for Sat. I have a couple of questions. I know to disconnect the sway bars to allow more contact patch with the ground. My question is what do you guys do for tire pressure in the wet? Do people drop pressure in rear only or not change a thing at all? Just looking for some setup advise. Thanks guys & gals. ALLEN

#2

I’d disconnect the rear bar only, and run a couple psi higher for air pressure.

Tire pressure growth is going to be less in the wet because the tires run cooler. 1) You’re not driving as hard and 2) The water removes heat from the tires and brakes there’s a heat loss mechanism that normally isn’t there. Less tire pressure growth means higher starting pressures.

Hopefully someone else will chime in that has some real knowledge on wet setup, as opposed to my ideas that I dreamed up only because they seem to make sense, vs. me actually “knowing” they are the right approach.

#3

+1

Disconnect the rear sway to reduce oversteer and raise the tire pressures 2-4psi. In cool weather and a track that will be wet for the entire race, favor the higher starting pressure. If it looks like the track many not be wet for the entire race, favor the lower starting pressure.

#4

I leave everything as is from the dry.

But then again I’m lazy and don’t want to be messing with the car while it’s pouring outside.

#5

I never will understand the “disconnect the rear bar only” camp. If you want to make sure you can’t get the car to rotate, do that. If you want it balanced, disconnect both. I haven’t found the pressure trick. Fowler swears by usin higher hot pressures to open the tread up. Some advocate lower pressure. I dunno.

The main trick is to adjust to the rain line. Don’t use the race line if the asphalt is polished (eg Turn 7 at RA - go past normal turn in, crank the wheel and when the car is almost settled get back on the gas).

#6

[quote=“epalacio19” post=54904]I leave everything as is from the dry.

But then again I’m lazy and don’t want to be messing with the car while it’s pouring outside.[/quote]

Lol, hey someone else like me. I need to work on my driving in the rain changing the setup does nothing for me, and I’m lazy.

#7

Amen! (I’m thinking back to RA in December…)

#8

[quote=“epalacio19” post=54904]I leave everything as is from the dry.

But then again I’m lazy and don’t want to be messing with the car while it’s pouring outside.[/quote]

Do what Eric does, he’s fast in the rain.
Do what Johan does, he’s fast in the rain.

I have been fast in the rain, but last RA race I just tippe-toed around.

I try to do what Eric and Johan do…nothing, but do drive the car carefully. Remember, unless there is potential to hydroplane, that a straightaway is for flat on the floor gas pedal. Easy into the brakes, but don’t timid-up you braking zone too much. Maybe soften the bar at the rear. The sooner you can get on the gas the better. A little more slow in, fast out approach. Follow the dry track of others. Stay away from standing water. No real secrets…well, maybe, be like King Cobetto and learn to be fearless.

RP

PS, who cares what the pressure is, I want some tread depth to channel-off the water.

#9

Stay away from the edge of the track when braking after a long/fast straight - 2 or more off in the rain can be game over.

#10

Allen, what did yu find from driving in the rain for 1.5 days?
(My guess, you drive as fast as you feel comfortable. But, when you’re racing there is always someone that can drive less-comforable?)

RP

#11

I ended up disconnecting both the front and rear bars, uped the pressure by a couple of pounds, and I was on full tread depth RA-1’s. Also, I tend to run a couple or pounds less in the rear then the front in a dry setup and I put them all at the same pressure. I was driving at Barber, I don’t know if anyone has drivin Barber in the rain before but, it is MUCH diffrent then RA in the wet. The car was pretty neutral and I have to say pretty predictable. It was a DE so I was by no means going all out but I was pleased. There was A LOT of pooling on the track and also streams of water going across the track in several turns that made it “interesting”. The only time the car was not happy was when I hit the standing water, which could not be avoided, and the steams in the turns. When I hit the standing water I would just keep it to the wood until the back end stopped moving around and that seemed to work well. lol Like Robert said it depends on the confidence level and as mine went up thoughtout the day things got better and better. I hope this somehow helps someone else but I feel that a wet setup just depends on driver comfort and gonads. You can make any number of changes but if you drive like a pissed off teenager then it’s not really going to matter. I think seat time is the most important thing be it dry or wet. It was pretty funny when a 2010 GT3 had to give me the point by. lol I think I turned 2:14-2:13 a lap in the wet and on Sunday the track was pretty dry and I changed everything back to the dry setup and was turning low 1:52’s and high 1:51’s almost every lap traffic depending. ALLEN

#12

Personally I wouldn’t bother changing the “setup” on these cars. If you have a real race car, you’ll want to soften it up in a variety of ways for a wet track, but Spec E30’s are not exactly stiff to begin with. As Steve D said, the most important thing is having proper tires and knowing how and where to drive on a wet track. The goal is to eliminate time spent turning and hunt for dry spots. The “line” as you know it goes out the window. You’ll have more grip accelerating and decelerating than you will for cornering.