b'TECH TIP PAGE Tech Tip 42: Rookie racers tend to want larger tires in the rear of the car for grip under power.If the car has 50% or more front weight, that is a bad choice.When working to achieve neutralhandling balance, we actually need the tire sizes to match the cars front to rear weight bias. For example, Indy Cars, Formula Cars & Sprint Cars, have around 60% rear weight & 40% front. So, they need 60% of the total tire contact patch area in the rear & around 40% in the front.We see this size difference on these cars with huge meats in the rear & smaller fronts. Rear engine caror simply rear heavy carsbasically need tire contact patch area in the rear to match the cars rear weight bias.If there is more rear weight, the car needs more rear tire.If tire sizes dont match weight bias, achieving neutral handling balance is a harder job.In full bodied, front engine cars with 53% to 58% front weight bias, we actually need larger tires in the front.But no one does this. For this reason, running wider rear tires is not only of no benefit, it actually makes the job of achieving handling balance harder.So lets leave the monster rear tire sizes to the drag cars & run the same size tire on all four corners.Well go faster & have an easier job of tuning your car for neutral handling balance.Tech Tip 43: Bearing thrust load capacity, for hard cornering, is defined by several factors.The number of bearings in the unit, size of the bearings, angle of the bearings the race, materials used & contact surface area of the ball or roller bearings to the race. Todays hub bearing assemblies utilize angular contact ball bearing design, which loads the balls at an angle (similar to tapered roller bearings), increasing thrust load capacity over inline ball bearings. These offer lower friction & better fuel mileage than tapered roller bearings. But, they are not as capable of handing high G corner thrust loads we see with top level, high powered, big tired, race cars today. Hub bearing assemblies that utilize tapered roller bearings can be over 50% stronger than angular contact ball bearing hub assemblies, due to increased contact area of the roller bearing compared to the ball bearing.Tech Tip 44: How can we have more front end travel than ride height? The answer is simple.Were not measuring the two at the same spot.We measure ride height under the middle of the front clip dog legs on each side. Typically, this is about 1 behind the firewall. We measure front end travel in dive, under braking, at the front axle centerline (FACL). The rear of the car does not dive under braking, just the front. The rear axle centerline is the cars pivot axis under braking. So, as the car dives in front, the chassis angle (rake) increases as much as 3. To achieve this high front travel, the front crossmember is built 1-2 higher than the dog legs & rest of the chassis, for more ground clearance during dive travel.The ride height at the Dog Legs determine how far the chassis can travel.Ron often dives his race cars so the Dog Legs are 1/8 above ground.How much dive that is at the FACL, depends on how far forward the front crossmember is.Discuss your strategy with Ron Sutton.226'