|Wheelie bar height
There are two different heights, measuring from the center or the
bottom of the wheel to the ground. The first is the cold tire pressure
height, You should always be on the flattest ground you can find. Some Racers
will do this adjustment in the car trailer where the surface is flat. We also like
to have the driver in the car for this reading. If you're setting them with the tires cold,
and at a tire pressure that will be your standard, you should know what distance you want.
We will call this the cold tire pressure reading.
The second reading is the height after the burnout. When the tires get hotter, they grow and the height changes. So, after the burnout see how much the wheelie bar moves up. Have a measurement that you use and go up or down on one or both, it just depends on the track and the wheel strike. We're talking very slight adjustments at that point. Know where you want to be within an eighth of an inch.
The strike marks are used for two reasons. Generally you'll have two strikes. You're going to strike them immediately, this length is usually 6 to 8 inches.Then there will be a break then the car is going to get up on the tire. this second strike can also be 6 to 8 inches long. On a really good balanced run our second group of marks will just be very lite as the front end will start to come up. So, we're looking at the distance of those two marks. IF the first strike is very BOLD come up on the bars, or retard more timing to pull some power. You can also tell by the width of the chalk how hard they struck. If the chalk is wide, meaning you hit hard, you'll want to raise them up a little bit or make a front shock adjustment, or your pinion angle may be to negetive. A low pinion angle will drive the bars hard into the pavement on the launch. I try to keep the strike distance equal but with some cars this doesn’t always become the case. Remember to run stagger on the height. The driver's side a 1/4 inch higher, typically, than the passenger side because that's the side that is going to hit first. You can control the car from going left to right, but you shouldn't steer the car with the wheelie bars, that should be done with the 4 link, or a front shock or front coil adjustment.