We're back with some more odd-sounding setup tips on how to make FWD track cars fast.
Add Toe-Out to the front wheels
Adding front toe-out is common sense for racers and autocrossers, but is something that many drivers avoid on street-driven track cars. Most drivers will put a tiny bit of toe-in or run zero toe in the front of their FWD track cars. This is great for straight-line stability on the street, but will greatly hinder the car's ability to turn in.
For a track car, start with 0.1 deg (or 1/16 in) total toe-out up front. This is just enough to make the car easier to turn during the entry phase of each corner, but not enough to cause the car to wander or become tail-happy. If you are worried about the car becoming tail happy, dial in a tiny bit of toe-in in the rear. The result should be a car that is stable under hard braking and is eager to point to the apex at turn-in.
Use less camber in the rear
This one comes straight out of the setup books of my good friend and mentor, Todd Reid. Todd took the unusual approach of running as little camber as possible on the rear of his NASA PTE-prepared Ford Probe. Convention says that this would result in a reduction of the rear contact patch due to the outside rear wheel going to positive camber, and this isn't entirely false. But it also makes it possible to rotate the car mid-corner, which is something that a lot of FWD track cars will refuse to do. The extra contact patch from the lack of negative camber also adds stability under braking and through the exit of every corner.
This is Todd's Probe. This car graced the podium at the NASA Nationals a few years ago and was a regular winner at various organizations up and down the east coast. Never mind the 20 year old paint or the oddball air intake. Instead, look closely at the camber angle of the left front versus that of the left rear.
Almost all modern FWD passenger cars will naturally gain more negative camber in the rear than they do in the front, so don't be afraid to stand the rear wheels up. If you have a Macpherson strut / Chapman strut rear, try reducing the camber angle of the rear wheels to half a degree less than the front. If you have a double A-arm rear, try it with a full degree less than the front. It won't drastically change the handling feel, but it will make it easier to control the car.
In addition to being a veritable fountain of knowledge of vehicle dynamics and racing technique, Todd is also a pro driver coach. If you can spare the cash, have him spend a day or a weekend with you. It's worth every penny and then some. For more info, visit www.reidspeedinc.com or call (410) 441-0201.
That's all for today. Click here for part 3, where we'll talk about weight distribution and brake bias.
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