Wheels/tires for a chump car

[Axxe]

38 hot is our target. When i came in after pushing for about 10 laps, the tires were greased to hell near the end and pressure was at 43. Felt like driving on ice.

[kronus]

We shoot for 34-35 hot, 28/29 cold.

[chip]

Thanks guys. This is super helpful. I'm now looking at:

http://www.tirerack.com/wheels/WheelCloseUpServlet?target=runWheelSearch&initialPartNumber=K8R581LG&wheelMake=Kosei&wheelModel=K8R&wheelFinish=Light+Grey+Painted&autoMake=BMW&autoModel=2002&autoYear=1975&autoModClar=

15x8, +20 offset. I can get them at a good price and will run 225/45/15 RS3 on them.

We run 15x7 Team Dynamics Pro Race 1.2 on our e30 chumpcar and on my spece30. Used to run the D-Force but found that they don't stand up to any abuse and bend easy. Haven't seen this issue with the TD's. We run Falken 615's in the 205/50-15 size. This has been a solid setup and hard to beat on price and performance.
#205 Ronald's Racers

[GillesBigCowboy]

I have always run 15x7 Kosei K1 with 205s in spece30 (toyo RA1 and R8eight) and in a couple of Chump races (Rivals). No complaints on any of them, but on the long carousel turn at Atlanta Motorsports Park last November, it seemed clear that many of our chump competitors had more ultimate cornering grip than us. The e30 was great in transitions, great under braking, and relatively strong on straights, but in that long steady carousel I could see the gaps open with many cars I was chasing (faster and slower cars).

I am just thinking (hoping) that 225s on some 15x8s will give us a bit more cornering grip..

As for tire pressures, I have never been able to scientifically test what is ideal. I usually start at 28.5ish on outside front and 30ish on inside rear (cold) with any tire I have run. I sometimes add or subtract a bit to get around 36-8ish hot all around, but really, I have no idea what is best.

[olddude13]

olddude13 Here, We run a e30 in chumpcar and run oz wheels 16/7 superturismo WRC
tires are 225/50R16 Dunlop Direzza Z11 If it matters we run a m52 engine
tire rack will heat cycle your tires for you, or you can do it at a track day the key is to let them sit and they will last a lot longer.

[olddude13]

I forgot to mention you will need wheel spacers F/R i think .25'' thick

[Blue55]

I've decided to go with these http://www.tirerack.com/wheels/Wheel...5&autoModClar=
and run 225/45/15 RS3 for now. We can't run spacers so this should do the trick.

[olddude13]

why no spacers?

[Blue55]

why no spacers?

Chump Car has a points system and running spacers will add in points that we cannot afford.

[GillesBigCowboy]

When are you racing the new stuff?
Let us know how it works.

[Blue55]

When are you racing the new stuff?
Let us know how it works.

We are planning on our first race being June 5-6. It's gonna be tight!

[liquidgroove]

I would put 205 on 15x8 and 225 on 15x9

in my experience with 205/50/15 and 225/45/15 R1R, 205 on 15x8 is just as fast as 225 on 15x8.

Just my $0.02

[ajhostetter]

I have RS-3s (225/45/15) and TRM C-1s in 15x8 on my S52d E30. I'm lowered on Vogtland coils and had to roll the rear fenders. No issues with rubbing. It's an awesome setup that I think you'll really like for chump. I second watching the air pressure. I can post a pic of the car if you want to see it.