atc5

iTrader: (2)

I've got an HPDE event this weekend at Sears Point with my ITR....looks like it will likely be a wet event.

The last time I drove on track in the wet/rain was 7 years ago.

I have brand new tires on the car...curious if I should drop pressures?

This will be the first time driving the ITR in a wet/rainy track environment so any insight is appreciated.

TPB

Focus on being smooth with all your inputs and you'll quickly discover what to do with your tire pressures after a few laps. Since it's an hpde build up your speed gradually as you get more comfortable with the track and it's conditions.

Lo-Buck EF

Outside and off the sealer.

wanabgts1

If there is standing water alot of times raising the tire pressure helps alot. The hoosier rep told me this one time as while going straight they will shed water better, and during turning they "squeeze" water to the outside of the tread blocks.

All the other advice here is good, I have found over the years that the better I get with my left foot on the brake the fast I am in the wet. I constantly use it to stabilize the car and trailbrake all the way to the apex while transitioning with the right foot on the gas. Makes for fast exits and smooth lines!

Zack

Xian

For a DE, just work up to the speed... cold pressures can be higher than normal. I'd probably be looking to start somewhere around 30/34 for my stock ITR. Is your car on stock suspension?

Christian

atc5

iTrader: (2)

I am on stock springs with adjustable struts (bought the car that way).

I just got the car a month ago so this will be my first event with it.

I've participated in many driving events over the last 12 years...99% of them on dry track.

Xian

You'll be fine... I've got revalved Bilsteins and a 26mm bar and the car was still easy to drive in the rain. Just remember to feed in throttle to plant the rear and be smooth on your inputs. The ITR also has really good ABS that should help you out.

jdmspoonitr

iTrader: (1)

Yep rainy trackday are pretty fun. Teaches you a bit more about car control. You'll probably be going a lot slower, but it's still a lot of fun correcting the car etc if you are too harsh on turn in.

dirty19

iTrader: (1)

Being careful and more aware of the changing driving line at Sonoma is the key.
You have been there before so you are familiar with the track.
Also keep in mind that that track is even more treacherous in the wet.
I know a few people who totalled their cars there.
Patience is important.

MBellRacing

Sonoma is the second most difficult track I've ever driven in the wet. Here are things to remember:

The usual "dry" line is very polished and rubbered up, this means it is EXTREMELY slippery. I've walked this track in the wet and have almost slipped just trying to keep on my feet where the track is polished. Due to this, do your important uses of traction (braking, power-on, big transitions, apexes) off the dry line, or on the "wet" line. Where you do have to cross the dry line, do it carefully and with a stable platform. The right line will seem like you're just running the outside around every corner. This isn't completely true, but close. Brake slightly off line, wait to roll to power till you're straight, and avoid the dry line apexes. At T2 and T4, your line should be as close to the dirt on the outside as possible. Also, keep the HELL off the curbs. Don't even get close to them. They're simply terrible in the wet.

The wet will highlight any rough driving issues you have already. If you're a bit choppy with your downshifts or snappy on throttle, this will show up in a huge way in the wet. Keep your eyes up, even when things get a bit dicey, and think logically about where things will be slick. Sonoma isn't as simple as trying to aim for the matte or shiny surfaces since it has been sealed so many times.

The other big thing about Sonoma is "Lake Infineon" over at turn 10. Aim straight and prepare to dive. Hold the throttle steady, don't move the rudder, and ride it out. There may also be a lot of little rivers down on T3 and through the Esses.

As far as setup, most people drop the sway bars and lower tire pressure to match your dry pressure. If you have an adjuster, take some rear brake bias out as well.

dirty19

iTrader: (1)

Thanks for chiming in Matt... I was hoping you would find this thread.
There was a post a while back where you posted some wet driving.
I was too lazy to go and find it for the OP.

MBellRacing

I have posted wet driving videos in the past, but neither really shows the proper rain line, which is the important thing. Here's one of those videos. It was a wet qualifying session (yes, rare) on a track with VERY little rubber (then new NJMP Thunderbolt). Even still, you can see where I lose a lot of grip or, in subtle ways, avoid some apexes from the rubber just that weekend in practice. I also had a couple ugly downshifts and gave 'er a bit too much brake in a couple corners as well, showing how easy it is to make simple mistakes when you're working with roughly half the traction. These laps were mostly recon-- I had to sort out where the grip was quickly to put down a good qually lap. In this case, it was good for pole by 0.04 seconds in a very competitive (then) Koni Challenge GS class.

Calif_Kid

Lots of good advice... As far as rivers are concerned, sometimes there will be one on the straight between turns 6 & 7, plus there is usually one where turn 1 is. The rivers at turns 1 & 10 will move/shift the car sideways quite a ways (seems like 10' for turn 1). As was mentioned, stay off the curbs/berms, as any painted areas will be really slick. One time in the rain at Infineon, I thought I was going slow enough before the braking zone before turn 4 (and I was braking right next to the left side rumble strip), but the tires locked up solid and the car just slid merrily along, but eventually I got the tires unlocked and just made the turn - the point was that when braking, you may need to be well off the normal braking line as the normal braking line may be slick. - Jim

Xian

Something else to note (although it shouldn't be an issue at a DE) is that curbing will often hold water long after you have a solid dry line. If you get up on the curbs, things can go all pear shaped in a hurry since it'll be wet and slippery on the paint. And if you migrate off the curb to the grass it'll get even worse...

Egezzy

iTrader: (2)

I LOL'd!

granracing

I prefer to race in the rain than on a dry track. In addition to what has been said, try to round our your corners a bit more than you might in the dry.

Matt mentioned sorting out where the grip is, which is key. While there's the general wet line, you'll find that as conditions change so will where some of the areas of grip. Don't be afraid to adjust your line even in the same session. It's an HPDE, so experiment a bit with some different lines. Know what spots you can take a bit more risks than others. Do ease your way into going faster.

Have fun with it. You might be asking tracks to install sprinkler systems like me.

hondalx97

i agree with him, my first whole season of autox was in the rain, i learned much much more than i have on dry days, and i tend to be much faster in the rain for sure.. i perfer it, but like pretty much everyone else said, BE SMOOTH, there is much less grip out there and upsetting the car will only end poorly you really have to be careful with your transitions into and out of corners just take your time and the times will tick down

dirty19

iTrader: (1)

Where do you live where they run a whole auto x season in the wet?
Thats terrible

tronic

Maybe I missed, it but what kind of tires are you running?
Brand new Hoosier R6 might be a little scary in the rain..
Some sub-200 treadwear tires are a lot better than others in the rain.
Normal all season street tires should be pretty predictable.

In general, I would say to take it easy on your first few laps. Play it safe and build up your comfort and confidence with the grip you have. Tires will heat up much more slowly, if at all, in water and cooler temps. Expect more understeer at corner entry, so it's a good time to practice "slow in, fast out". Also be aware of how your brakes are handling the water and be cautious in hard braking zones.

MBellRacing

Just drive under whatever tire you have. I've driven on random-model Continentals on Audi S4's there with no issues. Take it easy, all the same rules apply. Sonoma is busy enough you shouldn't have to worry about brakes.

hondalx97

haha i'm outside DC but i do events all over va and MD, two years ago we had a TON of rain i only ran maybe one dry event, it was intresting lol.

to the other post, hoosier in the rain... no bueno, they just let go out of no where. A/S you know whats going to happen. thats why i have also run in the street tire class honestly most tracks i can come pretty close to the people running R comps some tracks you can even run the same kind of times, the newer street tires can be very very good tires