wheelie bar advice

Dave what do you think about this :

Top Wheelie Bar Setup Tips: Chassis Engineering

“Mostly people ask how long they should make the wheelie bars, and we usually tell them to get the 84” bars and cut them down as they see fit,”
“The longer you make the bar, the higher you need to make the bar when you start off. What ends up happening is that the shorter the bar, the longer the period of time it takes for the bar to hit the ground."
"In the 64-70” range, you can start with a 6-6.5 inch high and about a 1/4 stagger.”
“While in the pits, chalk your bars to see how they are hitting the track on launch."
"When you get to the line, measure the bars on the starting from the ground to the center of the pin on the wheel, while pulling the bars up to take the slack out.
"When you start going really fast, you use the bars to control wheel speed. As you raise the wheelie bar up, you take wheel speed away. Lowering it adds wheel speed. It doesn’t allow the wheel to compress as far, which allows the tire to spin. A good race track will make the car faster by lowering the wheelie bars, but as the track goes away, raise the bar.”

They forgot to mention that the slick's air pressure & diameter (and/or sidewall height) effects the total amount of slick wind-up and thus can also effect the desired/required bar wheel height off the ground for any given combo.

As for their "6-6.5 inch high" number off the ground, not everyone measures from the center of the wheel. Some do measure from the bottom of the wheel instead. No real reason why some use one measurement point vs the other, it's just a personal preference thing.

Good Reading!

I run a single wheelie bar. I'm not a fan of steering the car with the either .ie (stager) if for some reason your bar gets out the the perfect groove it will drive the car one way or the other. also if your tire pressure moves around it the staging lane it makes it steer the car as well. I guess if you had someone check the bars every time you staged the car and never got out of shape in the firsts 60' it whould be just fine. but the rest of the time its just a gamble ...JMO

The truth is a single wheel wheelie bar can steer a car around in the groove just as easily, and sometimes even worse depending on the combo & power numbers.

Some people that might be having problems with the car walking around in the groove while on the bars mistakenly blame the style of wheelie bar (single or double) for causing the problem. But a lot of times the problem is really that (A) they unknowingly staged the car crooked, and are having to play the "steering wheel catch-up" game, or (B) the track had too much excess rubber buildup causing the car to move around as the wheelie bar wheel(s) gets pushed around ridding up/down the excess grove rubber buildup and/or ruts in the excess rubber build-up.

I know some guys that before they added more power to their car they could have easily used a single wheel wheelie bar with no problems. At that point their car's required preload needs to both launch straight, & also drive straight further down track, where exactly the same. So at that point there was no need for any wheelie bar stagger. But after they added more power the preload setting needed to drive the car perfectly straight further down track was also causing the car to go left at the launch. This is a situation where being able to stagger the wheelie bars really comes in handy.


I have also noticed a few situations where a single wheel wheelie bar can cause some cars to exhibit body-roll even though the car has an anti-roll. My buddy's ugly Willys had this problem when it first came out. At first it was thought that the car's anti-roll had broke/bent/failed. But after studying the launch video it was discovered that the body-roll was really caused from the single wheel being in the center of the car. Since the centered wheel created a pivot/roll point in the center of the car (while on the wheelie bar) it increased the torque/roll loading over to the passenger (right) side slick compressing it even more than normal during sidewall wind-up at the launch.


Here's an example of the effect.
https://www.youtube.com/watch?v=233_ZuAv6_8

If you look closely in the video you can see that both the bottom of the body & the rear housing are at the same angle (so the anti-roll is doing it's job).

WHY DO YOU NEED WHEELIE BARS BRUNO YOUR WAY TO SLOW FOR THAT

thxs for the advice gerry .........

If your chassis is setup to hit the tires equal then a single bars is fine.if you have a dual wheelie bar to correct chassis issues then your using them for the wrong reason. You can adjust the car to launch strait. It is not for the novice car guy but is doable.

fe50stang wrote:If your chassis is setup to hit the tires equal then a single bars is fine.if you have a dual wheelie bar to correct chassis issues then your using them for the wrong reason. You can adjust the car to launch strait. It is not for the novice car guy but is doable.

You just don't see many cars using a single. Does this mean that every ProStock car is not set up right? Or most ADRL cars?