Improve handling in the rain?
Improve handling in the rain? Just participated in a HPDE at Atlanta Motorsports Park last week in the pouring rain. Obviously, torque + a wet track make for an interesting experience. My question: Is there anything we can do to meaningfully help our handling in these situations?
Obviously tires are a no brainer. I'm running Nitto 555R II's and that coupled with pooling water on the track make for a nasty combination. Obviously, I'll need to get an extra set of wheels with tires that work well in the rain. Aside from that, what else is out there that will help?
For the sake of comparison (and I understand it's apples and oranges), my car would slide out by gently rolling into the throttle in 3rd gear at 65 mph whereas my instructors car (BMW M Roadster on street tires) would handle just about any power he was trying to give to it. I understand that torque and tires play a big role in that, however it would be nice to put a little bit of the power down in those conditions. Whereas the car could get to 115+ mph on the front straight on a dry track, I was spinning at 65 in the rain.
Obviously tires are a no brainer. I'm running Nitto 555R II's and that coupled with pooling water on the track make for a nasty combination. Obviously, I'll need to get an extra set of wheels with tires that work well in the rain. Aside from that, what else is out there that will help?
For the sake of comparison (and I understand it's apples and oranges), my car would slide out by gently rolling into the throttle in 3rd gear at 65 mph whereas my instructors car (BMW M Roadster on street tires) would handle just about any power he was trying to give to it. I understand that torque and tires play a big role in that, however it would be nice to put a little bit of the power down in those conditions. Whereas the car could get to 115+ mph on the front straight on a dry track, I was spinning at 65 in the rain.
I'll stick my neck out a little and say this...if the car currently suits your driving style when the track is dry, then tires and driving style are what are going to allow you to drive fast in the rain. Consider this, while NASCAR currently doesn't race in the rain, so people aren't really familiar with wet surface racing, F1 does run in the wet. They only change when the skies open up? Tires.........
I'll stick my neck out a little and say this...if the car currently suits your driving style when the track is dry, then tires and driving style are what are going to allow you to drive fast in the rain. Consider this, while NASCAR currently doesn't race in the rain, so people aren't really familiar with wet surface racing, F1 does run in the wet. They only change when the skies open up? Tires.........
TECH Apprentice
Joined: Dec 2006
Posts: 343
Likes: 1
From: Petaluma, Ca
You can disconnect one side of the rear swaybar or take it off completely. Also, in my case, I have phb relocation brackets, so if it was me driving in the rain, I would raise the phb back up. If you had a watts link you could adjust that up also. Frrax might have some more in depth answers for you.
Last edited by ChrisRZ28; Apr 24, 2013 at 08:30 PM.
There a few things I learned from racing karts in the rain that may help.
In the rain:
-you want weight transfer to the wheels that are looking for traction, this goes for braking, cornering and accelerating
-big sway bars will hurt you, may work better if they were disconnected.
-short shift to reduce torque off the drive tires
-if you can soften the shocks, that helps transfer too.
-a good fresh sharp street tire typically work better in the wet. Or a wet race tire. Narrower is you friend too.
-throttle and brake, I always imagine I have an egg between my foot and the pedal I am pushing. Try not to break the egg. Gently build the pressure, whether threshold braking or accelerating.
-wet race lines are way different than a dry line. You go where you would never go in the dry. Tires smooth the asphalt on the dry race line, you want rough asphalt to bit into the tire. In the karts we would run right on the outside edge of the corner at the apex. You had to be very careful getting to the outside though as you had to cross the normal turn in point of the dry race line briefly and it was slick as snot before you got to the unused section of the corner, same went for the straightaways, go where you normally wouldn't.
As a further example of transfer, in the karts we would lean towards the outside of the corner in the rain to put more weight on the outside tires. You want your car to do the same. It was way faster than anyone who tried the to lean in like you did in the dry. A very different approach.
Hopefully that gives you some ideas.
In the rain:
-you want weight transfer to the wheels that are looking for traction, this goes for braking, cornering and accelerating
-big sway bars will hurt you, may work better if they were disconnected.
-short shift to reduce torque off the drive tires
-if you can soften the shocks, that helps transfer too.
-a good fresh sharp street tire typically work better in the wet. Or a wet race tire. Narrower is you friend too.
-throttle and brake, I always imagine I have an egg between my foot and the pedal I am pushing. Try not to break the egg. Gently build the pressure, whether threshold braking or accelerating.
-wet race lines are way different than a dry line. You go where you would never go in the dry. Tires smooth the asphalt on the dry race line, you want rough asphalt to bit into the tire. In the karts we would run right on the outside edge of the corner at the apex. You had to be very careful getting to the outside though as you had to cross the normal turn in point of the dry race line briefly and it was slick as snot before you got to the unused section of the corner, same went for the straightaways, go where you normally wouldn't.
As a further example of transfer, in the karts we would lean towards the outside of the corner in the rain to put more weight on the outside tires. You want your car to do the same. It was way faster than anyone who tried the to lean in like you did in the dry. A very different approach.
Hopefully that gives you some ideas.
Last edited by RAMPANT; Apr 24, 2013 at 08:31 PM.
There a few things I learned from racing karts in the rain that may help.
In the rain:
-you want weight transfer to the wheels that are looking for traction, this goes for braking, cornering and accelerating
-big sway bars will hurt you, may work better if they were disconnected.
-short shift to reduce torque off the drive tires
-if you can soften the shocks, that helps transfer too.
-a good fresh sharp street tire typically work better in the wet. Or a wet race tire. Narrower is you friend too.
-throttle and brake, I always imagine I have an egg between my foot and the pedal I am pushing. Try not to break the egg. Gently build the pressure, whether threshold braking or accelerating.
-wet race lines are way different than a dry line. You go where you would never go in the dry. Tires smooth the asphalt on the dry race line, you want rough asphalt to bit into the tire. In the karts we would run right on the outside edge of the corner at the apex. You had to be very careful getting to the outside though as you had to cross the normal turn in point of the dry race line briefly and it was slick as snot before you got to the unused section of the corner, same went for the straightaways, go where you normally wouldn't.
As a further example of transfer, in the karts we would lean towards the outside of the corner in the rain to put more weight on the outside tires. You want your car to do the same. It was way faster than anyone who tried the to lean in like you did in the dry. A very different approach.
Hopefully that gives you some ideas.
In the rain:
-you want weight transfer to the wheels that are looking for traction, this goes for braking, cornering and accelerating
-big sway bars will hurt you, may work better if they were disconnected.
-short shift to reduce torque off the drive tires
-if you can soften the shocks, that helps transfer too.
-a good fresh sharp street tire typically work better in the wet. Or a wet race tire. Narrower is you friend too.
-throttle and brake, I always imagine I have an egg between my foot and the pedal I am pushing. Try not to break the egg. Gently build the pressure, whether threshold braking or accelerating.
-wet race lines are way different than a dry line. You go where you would never go in the dry. Tires smooth the asphalt on the dry race line, you want rough asphalt to bit into the tire. In the karts we would run right on the outside edge of the corner at the apex. You had to be very careful getting to the outside though as you had to cross the normal turn in point of the dry race line briefly and it was slick as snot before you got to the unused section of the corner, same went for the straightaways, go where you normally wouldn't.
As a further example of transfer, in the karts we would lean towards the outside of the corner in the rain to put more weight on the outside tires. You want your car to do the same. It was way faster than anyone who tried the to lean in like you did in the dry. A very different approach.
Hopefully that gives you some ideas.
We employed a few of the techniques you mentioned above (short shifting, different wet line, very smooth rolling on throttle and braking -- even used the egg analogy) and they seemed to help. Also was certain to stay away from the gators or any other painted surface.
It's interesting to hear your thoughts on suspension. In theory I also thought softer shocks would improve wet traction however I wasn't certain if that proved to be true on the track. The issues with bigger sway bars make sense as well. In short, I guess many of the things we do to firm the car up for dry weather might work against us on a wet track.
It sounds like a good rain tire would be the single greatest thing I can do to help the car and then simply focus on the driving points you mentioned above.
Thanks!
