Setting Wheelie Bars (1 Viewer)

FABMAN

Nitro Member
To me there is nothing more irritating than watching crew member jack with wheelie bars at starting line. There's absolutely no reason why they cant do that in the pits especially pro teams that are pitted on pavement. Prove to me I'm wrong somebody!!!
 
To me there is nothing more irritating than watching crew member jack with wheelie bars at starting line. There's absolutely no reason why they cant do that in the pits especially pro teams that are pitted on pavement. Prove to me I'm wrong somebody!!!
I cant prove it to you this time of year, but can share my experiance on that.
It is crucial that the bars be set properly.
That is what steers the car when it leaves hard enough to lift the front wheels at the hit.
I have helped with that on a Top Sportsman car, the height is important for getting the right wheelspeed, and the differance in height is what steers the car.
The guy I helped had some handling "issues" that some thought were the drivers fault. He had lots of work done with the suspension, none of that helped.
Once the right setting was found, the car went straight as a sting and ran the best it hever had.
Someone else may be able to explain it better, but I hope that helps.

I have to go back to work, breaks over... :(
 
Yeah i always set my cars up at the shop that one less thing you have to do at races. It was an 8.50 car without stop and always went straight as an arrow. Just a light touch to keep wheels about 2" leaving the starting line. Don't see comp guys , Top Sportsman messing with bars at starting line either. Mostly Pro cars.
 
I think Del Worsham explained the importance of setting the bars in an article awhile ago. Pretty amazing actually. Not sure why it bugs you Jesse. Lifting the bodies on Funny Cars before a run must really make you crazy! (Just messin’ BTW) 😄
 
Well since I do it I will tell you.....on top fuel car we use either skid blocks mounted to the frame that are changed depending on track conditions or you use the bar depends on team and crew chief.....we do it to get wheel speed so it will only squat on the tire so far before it basically jumps back up on tire......I set it so close to the starting line cause on a dragster the bar is 30ft from the starting line at like indy there is an inch difference from where car stops backing up to starting line......skid blocks for some teams are in 10 or 15 thousands increments so an inch is a ton
 
Jesse, Let's assume you run a carburated car..... to a pro stock car leaving at 10/10ths (or a pro mod) setting the wheelie bar earlier would be like you setting the idle speed on your car once a year.

Now, could they do more to anticipate the necessary height and not take as long .... yes, most likely they could. Once they do one run in each lane, they have the data they need to do it faster (unless the driver is not capable of doing a consistent burnout).

Track humps before the starting line matter, but they don't change that much during the day ..... given the view/gauge they are using to set height with, I'd doubt they are much more accurate than 100 thou. I have a laser sensor monitoring the rear end height the entire run .... if the 60ft isn't what I expected that number is one of the first ones I look at (that plus the wheelie bar pressure sensor). Like roughly 2/3rds of TS/TD cars I'm leaving much closer to 4/10ths than 10/10ths.

Jeff
 
It's interesting how the wheelie bars have changed over the years. I watch the Pro Mods on computer a lot and you always see a crew member adjusting the bar, using a tape measure. And that begs a question. Why use a tape measure? Wouldn't there be a more accurate way to measure how high or low you want the bar? Also, what is the difference between running one long bar and running 2 bars? So would one bar work better on a solid mounted rear end and 2 bars on a suspended rear end? Just askin' cuz I think it's interesting to see how teams do things on various cars.
 
.on top fuel car we use either skid blocks mounted to the frame that are changed depending on track conditions or you use the bar depends on team and crew chief.....we do it to get wheel speed so it will only squat on the tire so far before it basically jumps back up on tire....skid blocks for some teams are in 10 or 15 thousands increments so an inch is a ton

Dale Armstrong put that 5th wheel hanging off the right side of Kenny Bernstein's car in 93 for just this purpose. They didn't stay with it, but this is all what he was trying to accomplish 25 years ago. Dale was a smart guy.
 
That's why we do it at the starting line or very close to it. The tracks we run at are not laser flat.

Rick

In the 18 years that I have been involved in running our blown '57 Chevy (7.60 index andt as quick as 7.24) we have only adjusted our wheelie-bars maybe 5 times. Adjustments are made by making sure the tire roll out is even (+/- 0.0625") by stretching the smaller one with more tire pressure. This is done in the morning in the pits and the extra air is released in the staging lanes. If more adjustment is needed, we will move a 4-link bar (usually the upper right-hand bar). Other than that, we trust our experienced driver to drive the car and give us feedback with what he wants.

Granted, we primarily race at Famoso Raceway which has been laser flatten and is always prepped like a national event. If we go to other tracks like Fontana, then we have to think more about how to grip the track. But we don't have an issue with going straight.
 
Where to begin. You have a rotating engine and a live floating rear-end (as oppose to a solid (fixed) rear-end) working against each other. you need to tune the chassis for weight transfer by making the car squat and hold the back-end stay true. When there is a bump in the lane it could unsettle back-end of the car or more commonly known as unload the chassis and the rear end could move side to side (doesn't take much). That's why you see these guys get off the throttle when the car starts swerving or for those who don't react in time t-bone the wall.

If you want to learn more about this, read this web page, It explains it pretty well.

http://www.baselinesuspensions.com/info/Launching_A_Drag_Car.htm
 
I think Del Worsham explained the importance of setting the bars in an article awhile ago. Pretty amazing actually. Not sure why it bugs you Jesse. Lifting the bodies on Funny Cars before a run must really make you crazy! (Just messin’ BTW) 😄
In the 18 years that I have been involved in running our blown '57 Chevy (7.60 index andt as quick as 7.24) we have only adjusted our wheelie-bars maybe 5 times. Adjustments are made by making sure the tire roll out is even (+/- 0.0625") by stretching the smaller one with more tire pressure. This is done in the morning in the pits and the extra air is released in the staging lanes. If more adjustment is needed, we will move a 4-link bar (usually the upper right-hand bar). Other than that, we trust our experienced driver to drive the car and give us feedback with what he wants.

Granted, we primarily race at Famoso Raceway which has been laser flatten and is always prepped like a national event. If we go to other tracks like Fontana, then we have to think more about how to grip the track. But we don't have an issue with going straight.
I think Del Worsham explained the importance of setting the bars in an article awhile ago. Pretty amazing actually. Not sure why it bugs you Jesse. Lifting the bodies on Funny Cars before a run must really make you crazy! (Just messin’ BTW) 😄
I ,urn
 
That was weird, good info guys in all my Drag Racing you want the car to go straight and be consistent. I guess pro guys are dealing with thousandths and might be a little messing with head too. Hey it gave us something to chat about.
 
I don't know about wheelie bars on the pro stock or T/S cars other than to say I went to the concrete pad at the scales at the IN N Out deal at Pomona with my ex pro stock RJ Camaro T/S car, set them and locked them down, and never messed with them again.

But for my TA/FC every run I would judge the conditions, the starting line traction, decide on how much power at the hit, adjust tire pressure and then on the starting line adjust the wheelie bar up or down for one purpose, and it wasn't wheelie's. It was wheel speed. Get it wrong and you'll shake your brains out. It had absolutely nothing to do with wheelies at all. Sometimes you hit it, sometimes you didn't.

Here's one of my favorite shots taken almost 20 years ago taken at Sears Point. Unbelievable wheel speed and it did not shake. To bad the red light was on.

Pete Swayne Sears Point 1998.jpg
 
It's interesting how the wheelie bars have changed over the years. I watch the Pro Mods on computer a lot and you always see a crew member adjusting the bar, using a tape measure. And that begs a question. Why use a tape measure? Wouldn't there be a more accurate way to measure how high or low you want the bar? Also, what is the difference between running one long bar and running 2 bars? So would one bar work better on a solid mounted rear end and 2 bars on a suspended rear end? Just askin' cuz I think it's interesting to see how teams do things on various cars.
You can always get a calibrated tape measure. Yes, these things do exist 😂
http://www.transcat.com/calibration-services/instruments/tape-measure-calibration-labs/
 
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