24 replies to this topic

[Keith Novak]

Well, I was just trying to be helpful and share my experiences so that others don't get into a bad situation like I did.

Peace. Not trying to arugue or contradict.

I hear lots of different opininons when it comes to rain. I honestly don't know who's right but I'm always a touch skeptical when I hear, "I did this and here's the result."

The rainy double weekend Bruce mentions is a perfect example. To give you a perspective of how wet (this is no exaggeration BTW) lap times were 16-20 seconds slower, standing water everywhere, places you would not normally consider a turn were frightening, I pulled the cover off my car the morning of day 2 to find frogs on it, debris flags due to families of ducks crossing the course in my 1st qual... It was WET.

Winner of race 1 has full wets, but changed nothing else on the car except maybe pressures. Winner of race 2 disconnected both sway bars and raised the ride height to stay off the bump stops. They both won so it's hard for me to say either was wrong. What I question is whether it was the setup, or any combination of other variables.

[D. B. Cutler]

No problem. One thought that I did have was that there might be a difference between the track surfaces with regards to our different results. Grattan at the time was a very well worn track so maybe it didn't scuff the tires very well in the wet. Plus, I'm sure that their are differences in track construction between Michigan and the Northwest. Just thought.

That said it's not a myth. What happened to us happened. At the time, we normally ran mid pack. That day we were DFL through both wet sessions and were damn luck not to wreck both cars.

[FTodaro]

I have been reading this old thread on rain tires. getting ready for our season opener in NASA at Mid-Ohio. and yes rain is in the picture. I have had my best results last year in the rain but I did it on shaved RA-1 in those races the track was wet but not ponding with water.

My question: I know there are difference of opinion about what tire pressure you should run on a full tread rain. So I am interested in what people run and why. I recall some liking low pressure in the 20's and some wanting high pressure like 40's. So what the pressure you run and why?

[Keith Novak]

We've been having some very wet days so I've been thinking a lot about this too.

Lower pressures build more heat. The heat is a factor of friction, so when it's slick as snot, there's not much friction even if you're driving sideways around the whole track. You might build more heat than if you started at higher pressures, but you're still not going to get the tires blazing hot and the pressures don't climb much. Too low a pressure allows the tire to cup in the middle and when driving in heavy rain, hydroplaning can be a major concern.

My uneducated reasoning is leaning towards this... I want my finishing pressures somewhat lower than normal so I can get as much heat in the tires as possible. That still means starting somewhat higher than normal because I'm not going to build as much heat to raise the pressures.

Driving style is going to change how much heat you generate too. I've started changing the way I drive at the start to build the heat early. I'm not going gonzo bat s**t crazy, but I'll intentionally slide the car a bit more than normal, fully aware it's going to slide so I'm ready to react appropriately and have more room for error when it does.

Don't know if that's right or not, but that's where my train of thought has been drifting.

[Cy Peake]

In one of Ross Bentley's books, he recommends that the car be sliding all the time in a wet corner so that you know exactly where the limit is and don't get surprised. I've tried to do this and it's much easier said than done. However I usually do finish better when the track is wet and got my only win on a drying track.