b'TECH TIP PAGETe 3: Slip angle is the difference in angle of the wheel, relative to thech Tip 3tires contact patch, which is distorted due to cornering forces. The tires sidewall, carcass & tread all distortas the g forces are pushing the car towards the outside of the cornerand the tire is sticking to the track.Just for conversation, say the contact patch on the tire in the illustration isangled 8 outward from the wheel anglewe would say the tire has an 8 slip angle. That may, or may not, be at this tires optimum point of grip.Every tire is different, with tire design, sidewall construction, sidewallheight, wheel width-to-tire width ratio, tread type & depth all playing a role in what the Slip Angle Graph looks like for any given tire. See the graph below right for examples.The g forces cause the majority of the tire to be pulled outward with the weight of the car. But the contact patchwith tractionstays connected to the trackand is twisted toward the outside of the corner. The harder you drive the car, the higher the slip angles.A good driver learns the feel & characteristics of the tires they race on. They drive the tires up to the edge of that optimum grip feel constantly to win races. If they go past that edge the tire breaks traction. Look at the Slip Angle graph.The blue line is a racing radial slick, with the highestCOF (Coefficient of Friction) & grip. Notice how small the sweet spot at the top of grip is, then how sharply it falls off when driven past its limits. The red line is thebias ply slick. You can see it has less CoF & grip, but has a wider range of grip, which is much more forgiving.Todays low tread wear & DOT legal competition tiresperform somewhere in between the red & blue lines. For decades the front tire on the inside of the corner wasignored. To get the needed camber back in the day the inside tire had so little contact patch, Racers consideredthe inside front tire contact patch & grip a sacrifice.Not today. Now, all winning racers at top levels optimize the grip of the inside tire. If done right, we can add as much as 25% to the total front grip. How? Two keys. One, run the suspension strategy so the car has a much lower roll angle. Pro teams are aroundto 1 degree roll angle depending on the track. This loads the inside front tire more, increasing the slip angle on it & adding grip. But still not optimum.To get the inside front tire to create its highest level of grip, we need to mechanically twist the wheel furtherwith Ackerman. How much? Depends. If the car has a 3 roll angle, it doesnt matter, because that inside front tire isnt loaded at all. With a 1 roll angle car, optimum tire slip angle & grip on the inside tire is achieved with 2-2.5 Ackerman at 15 of steering. Pro racers with ultra-low 0.5 chassis roll angles find optimum slip angle & grip around 1-1.25 Ackerman at 15 steering. 424'