CART Extreme @ Road America

Tim O'Glock · Jul 22, 2018

Here are my setups for all four chassis. I created the base setup for the Reynard chassis and then made balance adjustments to make it work with the other cars. I managed to reduce drag and increase downforce considerably compared to the default setup. Lap times should be around 1.5s faster than default.

The Reynard is the fastest chassis around Road America (unless it's got a Toyota engine in the back). It is almost equalled by the Swift, which suffers from poor front downforce. The Lola is third fastest and about 0.4s slower than the Reynard and Swift. The Penske is useless on the straights and therefore the slowest car around Road America with a gap of almost 1s to the top cars.

Farrow_21 · Jul 22, 2018

Thank you so much this is a massive help for me i always struggled setting up the 98 CART. This gives me something nice to look at for understanding what changes the car likes.

Tim O'Glock · Jul 23, 2018

No problem. It's really not difficult at all. You just want the car as low as possible during the corners to maximise downforce and get a lower center of gravity at the same time. On some cars you have to be careful not to go too low but with these cars that's not an issue. In fact, if it was possible to lower the car by another 10mm, I would do so instantly.

Running an extremely stiff front suspension keeps the front down during cornering. This is were the biggest gains in terms of downforce and lap time are found. A very stiff rear suspension keeps the rear down under braking giving you greater stabiliy on corner entry and allowing you to brake later. Of course this usually comes at the expense of traction on corner exit but with these cars that effect appears to be very small.

On the straights you want the front and rear ride heights to be roughly the same to reduce drag. This can be achieved by balancing the front and rear suspension stiffnesses.

Anti-roll bars, weight distribution, wing and differential settings are used to balance the car in low and high speed corners. The rest of the setup options are of minor importance.