Wheelie bar newbie

[Todd Geisler]

Originally Posted by FED 387

Second qualifying pass it sounds/looks like you got off the gas---Did you???? are you lifting or are you keeping your foot in it???? comp 387

No, the second pass my opponant blew his tires off and had to peddle, so the sound you heard was his engine.

[Todd Geisler]

Originally Posted by FED 387

looking at some of your runs it looks like the front end is "bouncing" a little bobble just as it comes down from the launch a little which maybe makes the rear tires load/unload---Look at the car as it settles down from the launch---It looks like the front is TOO stiff a little up and down motion too like a little stutter---see what I mean???? also are you holding the steering wheel straight or are you kinda steering to the right a little???? have somebody film the car from behind too----maybe raise the bars a little more let the car come up see what happens you can always go back to the previous setting---Comp 387

if I soften the front end compression any less, the front end bounce gets progressively worse. I may need to make an adjustment to the anti-roll a little more, or possible stagger the wheelie bar wheels. The car has been pulling to the right recently. I just found the rod ends on the anti-roll links worn out with .050" of play in the rod end ball insert. I replace those rod ends and reset the preload to neutral with ballast equal to my weight in the driver seat.

I'd prefer to not have the car come up much higher. Its been pulling higher for the last two seasons and to be honest, it makes the car difficult to dribe in tems of concentrating on hitting shift points, etc. They way it was this race made the car much easier to concentrate on driving.

I guess after flattening the headers twice in the last month, it's really shaken my confidence not only in the car, but my driving concentration as well.

[FED 387]

You need to put limiters in to not allow the front suspension to bottom out ----also is this a street driven car too???? Take the front sway bar off entirely and try driving it---then put a rebuild kit in for the sway bar if you feel you need it---Really do not think you need a sway bar this I think is what is screwing you up a lot----Hell just get in and let er rip--I think you are becoming afraid of it too!!!! Concentrate on what you are doing and try to hit the shifts where you want them watch what is happening it still looks/sounds like you are lifting the peddle too on all but the last run---Try concentrating on a spot at the far end of the track AIM for it this will keep you from wandering all over instead of going straight---Really it looks pretty good but I still think you need to let the front rise a little and raise the bars and PUT some limiters in to keep the front end from bottoming out---Go look at a early camaro the malibu is basically the same fron endsee what they are doing and if it were me I'd get rid of the sway bar!!!! ----Dick

[Todd Geisler]

Originally Posted by FED 387

You need to put limiters in to not allow the front suspension to bottom out ----also is this a street driven car too???? Take the front sway bar off entirely and try driving it---then put a rebuild kit in for the sway bar if you feel you need it---Really do not think you need a sway bar this I think is what is screwing you up a lot----Hell just get in and let er rip--I think you are becoming afraid of it too!!!! Concentrate on what you are doing and try to hit the shifts where you want them watch what is happening it still looks/sounds like you are lifting the peddle too on all but the last run---Try concentrating on a spot at the far end of the track AIM for it this will keep you from wandering all over instead of going straight---Really it looks pretty good but I still think you need to let the front rise a little and raise the bars and PUT some limiters in to keep the front end from bottoming out---Go look at a early camaro the malibu is basically the same fron endsee what they are doing and if it were me I'd get rid of the sway bar!!!! ----Dick

There is no front sway bar. I was refering to the rear weld-in anti-roll bar previously. That device keeps the chassis level and eliminates the typical "G-body twist". The front suspension consists of stock GM A-arms with Global West Del-A-Lum bushings, QA1 double adjustable stocker star shocks, and Moroso 250 #/in rate "trick" springs. Oh yea, bolt style travel limiters on the upper A-arms.

I never lifted on any of the passes thoughout the day. If you hear anything that sounds like a varying engine rpm, it's either the car in the other lane, or the car behind me doing the burnout.

Do you mean limiters on the upper A-arms to limit front suspension drop? If so, the car already has those and currently can take 1" more travel out. I don't see how letting the front end rise more will keep the front end from bottoming out, on the landing I assume your refering to? If anything more front end height will make the landing potentially harder than it is which really isn't bad at all. On a good run, I can't even feel the front end come up or land, very smooth.

My concern with raising the bars is this. Currently they are set to where if the car comes up high enough to compress the wheelie bar spring to coil bind, the wheelie bar tubes will just clear the bottom of the bumper. If I raise them any higher, there's a risk of the bars hitting the bumper if it comes up high enough to coil bind the springs.

I laid out the wheelie bars on my CAD program and the current static height should allow for an approx 18" high wheelie. Now granted rear tire sidewall squat and some very minor pinion rotation take away some of the static wheelie bar wheel height upon launch.

[Mike Pearson]

The way to control the car is a balancing act between the shock adjustment and the wheelie bar height.First set the wheelie bars high and work with the front shocks until you get the car to leavethe best you canwith that setup. If your car is bouncing then your shock setting is way to loose. Start at about midpioint on the extension adjustment and as tight as you can get on the compression adjustment on the shocks. Then start to lower the wheelie bars a little at a time until they start to unload the chassis then back up to the point that it worked the best. Hopefully you have spring loaded bars. They are alot easier to work with.

Mike

[Jeff Teuton]

Mike has it right. It looks like what mine has been doing; that is getting on the bars, and not enough spring on the bar itself so it throws the front end down too hard and makes the bounce worse. In addition to what Mike said, try getting softer spring action on the bars so it rides and doesn't push the front end down. You want it to carry the front end and set it down, not push it down. At 9.50 you obviously have enough power to do that. Hope this helps.

[Todd Geisler]

Originally Posted by Jeff Teuton

Mike has it right. It looks like what mine has been doing; that is getting on the bars, and not enough spring on the bar itself so it throws the front end down too hard and makes the bounce worse. In addition to what Mike said, try getting softer spring action on the bars so it rides and doesn't push the front end down. You want it to carry the front end and set it down, not push it down. At 9.50 you obviously have enough power to do that. Hope this helps.

Ok, now I think i got what you guys were refering to. After watching all the video's several times it does look like the bars push the front end back down prematurely.

The bars are S&W 54" long chromoly and are spring loaded.

Any suggestions on reducing this tendancy?

Raise the bars up some more?

Tighten the front shock extension more?

take a little more travel out of the front end?

Without the bars it was carrying the front end further down track. Here's sample video of before the bars.

http://www.qis.net/~geislert/toddg.mpg

The front end in this video was a bit too loose as well.

[Mike Pearson]

Todd,

I would try all 3 of those areas. Mostly start to tighten the shocks. Paint the wheels with shoe polish and check to see how long you are going with the wheelie wheels touching the track surface. The travel can be limited but make sure that you use some type of a rubber or polyurethane snubber. if it hits the stop to hard it will unload the rear tires. The real secret is the front shocks. What type of car are you running?

Mike

[Jeff Teuton]

It looks good without the bars. I assume you prefer the bars for a safety margin. Like Mike says, I would go tight on the compression, and about middle on the extension on the front shocks and start there. I assume your bars are directly on the rear end; ie you do not have a four link to attach the bars to. Without the four link, when you get tighter on the converter just prior to launch, the bars move down. Mine are considerably higher than yours. I started @ 14" to the center bolt, and raised them to 15" trying to stop the front end from coming down and I was also getting a momentary unloading of the tires. Just enough unloading to demolish a trans last Friday night. I am going to lower the bars, but I am going to soften the springs on the bar itself so it hits and rides and does not push down so early. My car is a 68 Cuda with a 500 in low hp/high torque motor about 3400 lbs and runs 10.20. 1.40 60 ft. We have another car that is a Duster T/STK car and it is a 9.50 car small block 600 hp. We normally are about 13" to the middle of the bars, tight compression, and adjust the extension to suit the track on the front shocks. We are not at minimum weight, and when we are really desperate, we take the bars off and have total control with just the shocks. We have Cal Trac system. 1.26 60 ft 2900 lbs. These have worked for us, but the GM suspension might be different on the rear.

[Todd Geisler]

Originally Posted by Mike Pearson

Todd,

I would try all 3 of those areas. Mostly start to tighten the shocks. Paint the wheels with shoe polish and check to see how long you are going with the wheelie wheels touching the track surface. The travel can be limited but make sure that you use some type of a rubber or polyurethane snubber. if it hits the stop to hard it will unload the rear tires. The real secret is the front shocks. What type of car are you running?

Mike

1979 Chevy Malibu, stock suspension car, the teal one in the video's provided