Chassis Tuning
Iphone, slow-mo video of the launch. Moving the front ride height does something that I don’t think has been mentioned. You want the front end to rise as much as possible in a controlled way. Too fast and it tops out and it with bounce the rear tire. The best way to control it is with the shock. Lowering the front ride height makes it travel more, which takes more time, which can slow how quickly it tops out. Front height changes come with issues. Lowering the front ride height changes the % of rise. Which is the how much the rear of the car goes up and the axle goes down at launch. Which seems to be a good thing, but too much of a good thing and the tire is crushed or bounces. A bodies because of the short front spring section naturally have a high % of rise. Lowering the nose gives it more. This is VERY crude, but take a picture of the car from the side. Print it out and draw a line from the contact patch of the rear tire through the front spring eye.extending out forward through the car. This is the instant center line. Now draw a line parallel with the ground at about the height the cam is off the ground. This is a guess on where the neutral line would be. Now draw a line through about where the shifter ball would be on a stick car vertically, the center of gravity line. The intersection of the neutral and center of gravity line is the true center of gravity point. Where the instant center line and the neutral lines intersect determines the % of rise. Farther forward less rise, hits the tire softer. Farther rearward hits the tire harder. I just put /6 bars in my car, my car tops the front out perfectly with the 340 bars I had in it. However, because 340 bars have less stored energy I was on full loose on my front shocks. It was working so why change? Watching videos of my launch, the car transfers weight, the axle doesnt move in or out of the car. You can see the tire bulge at the bottom as it gets more weight and here is what I want to tune. After the tire shows the bulge only then does the car start to rotate and lift the nose. I’m trying to make it more of a seamless process instead of two distinct actions. /6 bars will have more stored energy. The nose should start to come up quicker which I can slow down with the shock if I have to and the car rotate a hair sooner.
Iphone, slow-mo video of the launch. Moving the front ride height does something that I don’t think has been mentioned. You want the front end to rise as much as possible in a controlled way. Too fast and it tops out and it with bounce the rear tire. The best way to control it is with the shock. Lowering the front ride height makes it travel more, which takes more time, which can slow how quickly it tops out. Front height changes come with issues. Lowering the front ride height changes the % of rise. Which is the how much the rear of the car goes up and the axle goes down at launch. Which seems to be a good thing, but too much of a good thing and the tire is crushed or bounces. A bodies because of the short front spring section naturally have a high % of rise. Lowering the nose gives it more. This is VERY crude, but take a picture of the car from the side. Print it out and draw a line from the contact patch of the rear tire through the front spring eye.extending out forward through the car. This is the instant center line. Now draw a line parallel with the ground at about the height the cam is off the ground. This is a guess on where the neutral line would be. Now draw a line through about where the shifter ball would be on a stick car vertically, the center of gravity line. The intersection of the neutral and center of gravity line is the true center of gravity point. Where the instant center line and the neutral lines intersect determines the % of rise. Farther forward less rise, hits the tire softer. Farther rearward hits the tire harder. I just put /6 bars in my car, my car tops the front out perfectly with the 340 bars I had in it. However, because 340 bars have less stored energy I was on full loose on my front shocks. It was working so why change? Watching videos of my launch, the car transfers weight, the axle doesnt move in or out of the car. You can see the tire bulge at the bottom as it gets more weight and here is what I want to tune. After the tire shows the bulge only then does the car start to rotate and lift the nose. I’m trying to make it more of a seamless process instead of two distinct actions. /6 bars will have more stored energy. The nose should start to come up quicker which I can slow down with the shock if I have to and the car rotate a hair sooner.
