Wheelie bar newbie
 

Hey guys,

I just installed a set of S&W 54" long tubular (spring loaded) wheelie bars and have some questions on the proper setup.

This is kinda long winded, so bear with me.

I recently installed the bars as well as swapping a set of 4.10 street gears for a set of 4.33 Pro gears. I did this with the rear out and before painting the housing I decided to take some measurements. As it turns out the housing was bent, enough so that it was 1/8" to 1/4" toe out. I measured using two pieces of angle iron 28" long clamped to the axle flanges. I worked with a local chassis shop and I cut the housing ends off and used the housing jig to properly locate and reweld them making the housing centerline/bore perfectly straight.

Fast forward to this past Sunday. First run the car came up real quick with decent air, mostly my fault for having the front shock extension too soft for the track/air conditions. It banged the bars pretty hard which wasn't too big a deal, but the car made a hard right pointing me at the retaining wall and I had to lift, then the front came crashing down. This flattened three header tubes, but luckily I see no other damage.

Next pass I take the bars off and darn if it don't go hard right again, but this time I'm able to complete the run, but used up a good deal of blacktop correcting the car direction. What I believe happened was with the rear tires toe out all these years, the car would naturally go straight, but when I fixed the housing, it uncovered a chassis mis-adjustment. With a simple adjustment to the anti-roll bar, the car went dead straight the rest of the day.

Now, a little background on the car. It's a stock suspension '79 Malibu with 10.5 x 28" stiff sidewall Hoosier slicks. It sometimes also runs on a 325/50-15 M/T Et Street Radial DOT tire. The car runs mid 9's with 60's in the low 1.3x's and best of 1.294 footbraking.

In real good spring/fall air it really wants to go on the bumper and I have to tighten down the front end and limit some travel. I figured I'd take the NHRA Stocker approach and install a set of wheelie bars as a safety device to allow the front end to come up and allow the small tire to stay planted, but use the bars to keep the car off the bumper.

After this recent "accident", I'm gun shy of trying the car with the bars again. I know with better air coming, it's gonna start pulling up higher and higher.

I did some layout on my CAD program simulating wheelie bar heights vs front wheel wheelie heights. The bars are as high as they will clear the bumper with the springs compressed. The static height is 7" to the bottom of the wheel or 9" to the axle centerline. With the springs compressed it adds 5" of static height to the wheelie bar. According to my drawing simulations, that should yield a wheelie of approx 18".

With no bars in average to decent air it'll pull the wheels anywhere from 18 to 24" and higher in real good air. It's been real close to the bumper several times, but luckily no contact and no reason to lift.

I was gonna speak with the salesman at S&W, but he wanted the bars set pretty low. My thinking is that works OK on chassis and back half cars, but goes against what I know how my car works on small tires and stock suspension.

So, do I keep the bars high as they are, or drop them down to start and raise them a little a time?

Also, I'm told the W/B's can steer a car while on the bars. I understand you stagger the left to right wheel height to steer the car. What is the recommended method to tune this?

I will give any more info you may need.

thanks for any help.

I'm real close to taking the bars off and let them collect dust, but would like try and make them work to add a bit of security of not hitting the bumper or having a reason to lift again.

Todd

Re: Wheelie bar newbie
 

Anyone???

TTT

Re: Wheelie bar newbie
 

Get a good alignment shop to check the rear end. If installed a little crooked, easy to happen, it will steer the car. Also check that the wheelie bars aren't steering the car when the front end is up. does the front lift evenly or is the left side higher?

Re: Wheelie bar newbie
 

Well,

I can't seem to find anyone who is willing to offer some insight on setting up wheelie bars on a small tire stock suspension car. Car goes straight now, no issues there. Just the car hasn't hooked once since the bars were installed, gears swapped and bent housing fixed.

The problem is I don't know if the bars are the root of the problem, or if the 10.5 x 28 Hoosier stiff sidewall slicks are shot (sidewalls broken down) after 32 runs.

Guess it's time to shyt can the bars and go back to what I used to do before.

Re: Wheelie bar newbie
 

Took the bars off this weekend and the car hooks fine without them again. Two runs on the stiff sidewall Hoosier slicks were 1.306 and 1.303 60's. That also tells me the tires are fine and the sidewalls aren't shot as some told me that could/would be after 35 runs.

Bad thing is on the third run I swapped the bias ply stiff sidewall slicks for a pair of Hoosier DOT D/R tires and proceeded to try and put the car on the bumper, lifted and flattened the headers again.

Guess I'm on my own trying to figure out these wheelie bars. Just hope I figure it out before I tear up much more stuff.

I fixed the headers today and need to schedule a front end alignment this week before next Saturdays race.

Wheelie bars are back on, just need to figure out a compromise of front end travel, shock settings and wheelie bar height to get it to not unload the tires.

Re: Wheelie bar newbie
 

Dang Todd, You've still got a rocket ! I dont have the exp with wheelie bars to give you. Theres guys on here that know how to get yours right , but I think you are working up to level of performance, on your own.

Good luck !!

Re: Wheelie bar newbie
 

put some weight in the front of the car.

Re: Wheelie bar newbie
 

Went back to the track again this weekend for our last MSRA race. I was hoping some of the suspension tweaks made this week would help tame the launch and avoid the high wheel stands. The cars not leaving perfect, but I'd say it's much, much better. The car will now run with the wheelie bars on and not unload the rear tires. The air quality was worse today as compared to last weekend, so the performance fell off a small amount.

All runs today were made on the new Hoosier 325/50-15 DOT Drag Radial tires.

60's were 1.296, 1.294, 1.299, 1.292, and1.308. The first four runs were shallow staged and the last I bumped in pretty deep in an attempt to help R/T on the .400 pro tree.

Here's some videos I had a racing buddy film so I can break down the launch frame-by-frame and study to see if any tuning changes are in order. Be warned they are a larger file size, approx 1.5 megs each. They were saved as a larger image size and higher quality.

http://www.qis.net/~geislert/Qualifying1.wmv

http://www.qis.net/~geislert/Qualifying2.wmv

http://www.qis.net/~geislert/1stround.wmv

http://www.qis.net/~geislert/2ndround.wmv

http://www.qis.net/~geislert/semifinal.wmv

BTW, changes made were tightening the front shock rebound by 4 more clicks. With even better air coming (hopefully) I expect to have to either tighten the shocks even more, or take some more travel out.

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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.

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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.

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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.

Re: Wheelie bar newbie
 

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.

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

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.

Re: Wheelie bar newbie
 

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

Re: Wheelie bar newbie
 

Thank you to everyone who has posted comments on the way the car is launching on the wheelie bars. I think you all have pointed out some key areas that need some sort of attention in one way or another.

I will make every attempt to dial this thing in better through the remaining time this fall and next spring. The compression side of the current Qa1 double stocker star shocks is maxed out, so I can't tune out more of the bounce without replacing the shocks. That parts upgrade is at the top of my list for winter upgrades.

I will try and work with the front shock rebound as well as the travel limiters and wheelie bar height to try and reduce or eliminate the tendancy for the bars to push the front end back down.

The S&W wheelie bars have a fixed spring setup that isn't adjustable like some bars are. The only way I can see to soften the spring is to find a suitable replacement that's softer, maybe some sort of valve spring or similar.

Again, thanks for taking time to review the video's and also for the comments made. This surely has helped me to narrow the areas in which to put my attention with tuning.

Todd Geisler

Re: Wheelie bar newbie
 

Before buying new try giving Hal Lees a call @ 336.859.0385 (Denton NC). He should be able to re-valve your current shocks an a very reasonable price.

Bill

Re: Wheelie bar newbie
 

Todd,

I had the QA1 shocks on my car and they would not control the bouncing either. I purchased a set of shocks from Santhuff Engineering in Texas. They were Quite expensive but they are a hand built unit.They completly eliminated the front end bounce and the tires rubbing the inner wheel wells. They are a large diameter shock and will require some modification to the lower a arms. These shocks will cure your prolems. I picked up 3 tenths by fixing the bouncing and the rubbing of the front tires on the wheel wells

Mike