FrontEngineDragsters.Org Forum
Drag Racing Discussions => Front Engine Dragsters => Topic started by: mrmopartech on August 12, 2017, 05:25:13 AM
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Looking for pictures of wheelie bars used on front engine diggers as we had a minor problem a few weeks ago.After installing a new P/G,with trans brake and new convertor,and doing some regular passes we launch on the trans brake and went straight up.The front wheels from pictures where at least 6-8 feet in the air,and my driver did not pedal the car and well,damage happened big time,wheels are done,front end damage,nothing that 600-1000$ can,t solve.So if you have pictures,send them along to me at:
penstarperformance@gmail.com
thanks,mrmopartech/Scott Preston
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Scott sorry to hear of the damage.
I'm about 250 miles east of you in central Maine.
I'll try to find some pictures of our bar.
Single wheel triple bar design.
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Scott here are a few
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welcome to the new front end wheelie club. we did this in may at the valley. it went to about 75-80*. my son said he tried to pedal it down. 50 yr old fed chassis just does not like those sudden stops to the ground. $1000 later and now we have 4' of straight pipe on the chassis thanks to dr david beard of n.h.. lol. we should have brought the wheelie bars. who would have thought that a bigger blower would do that..........
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3 tubes of CM no tie between the bars to allow some flex, not so stiff it unloads the slicks if you hit it too hard. WB set just 2" off the track.
But best is if you are picking the wheels up more than 3-4" ADD more balast to the front end. I can't tell you how many times I have suggested a racer add 20lbs and they went quicker.
It's all about car balance. I know some Comp Elim racers will move 5 lbs of weight 5".
If you hit the bar hard to unload the rear tires, it's a wasted run.
Jon
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Look at the top of any page here and you can see the bars on Glenn and Anne's car. Roughly 6' long and set at about 2" up just as Jon suggested.
Roo
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I run no bars, but use a shift timer as a learning device when changing combos.
In beginning, set up shift timer to shift almost immediately, then keep lengthening shift time till front end comes up. Then make changes to car to keep front down (weight, tire pressures, launch rpm, etc...).
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Heritage JrFuel is no allowed to run either a timed or RPM controlled shifter, driver controlled shifters only, also no delay or thottle controls.
I guess that's bracket racing, not heads-up racing.
Jon
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What's the advantages or disadvantages of single wheel vs. Double wheel?
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I may get a disagreement , but most fast cars I've seen run a single wheel WB, two could cause the car to steer. I've found a flexablr 3 tube set around 2" off track works best.
Now I've seen RED set their WB higher off the track, but they have worked more on moving the ballast around to end up with a better balanced car.
Call if you have anymore questions.
Jon, 805-444-4489 [ SoCal]
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Thanks!
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The Neil&Parks site has a great start with a wheel and tube that is perfect start to build your own set I agree that a single is best--two bars up top one lower- thing to remember is when you drill holes for length ( height) adjustment make the PRECISION not sloppy--that little wiggle from sloppy hole is enough to steer car--when centering always measure from axle flange or brake rotor--not the tires about 2 in off the pavement with driver in the car is close--higher and you will just experience wheels up and more violent launch that may upset car
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I kept it simple with the McKinney adjuster and did the 3 bar, no brace, 72" long bars.
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We run a 3 point, with a brace, .058 1.125 bar i believe. It's pretty stout. Typically i'll hit it for 4", then off for a foot, then i ride it for about 3 feet. We run right at 2" under the wheel. It'll float the front end about 2" in the air.
The bar was a little low in the attached picture, or the tire pressure was a little low. When we drop a 1/2#, we have to raise the bar. My kid monitors all that, so i don't know how much. on the flip side, when we go up a 1/2#, it'll fly the front end a little higher because it doesn't wad the tire up so much.
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im getting ready to do mine. concerning the brace, i can see how stiffening up the bar would help get on the tire sooner versus having soft bars. so, as a discussion point. if tire is wider then wheel creating soft sidewall with lot of wrap during launch then stiff bar might help out a bit with getting up on tire? and visa versa if running something like a wheel wider then tire to stiffen sidewall and stiff sidewall tire a softer bar would help to soften the hit as it would be more apt to get on the tire sooner?
thoughts?
im gonna go .125 wall 1.125 dia @ 5'. whats appropriate? some guys run short bars some guys run long bars. i have read in door-car world with big hp on pm's they will run a long bar. prob to help soften the hit a bit.
then on that note, more hp longer bar? so, say 200 mph or 1200 or so hp an hypothetical length of 5ft lets say and if running like A/F or faster then longer bar as those guys are more apt to use stiffer tire.
i guess point being could your 60's improve with a different bar length even though you have it tuned with the bar you have now. be interesting to see someones logs who has tried different length bars, stiff sidewall with braced bars versus non, and soft sidewall with stiff and soft bars.
anyways, i like this kind of stuff.
dean
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Never relied on the bar to launch , I worked to get the balance right to get a 4" rise at the leave and carry it for 20', wheelie bar was just a safety backup that ha no influence till the front comes up 1 foot. Using .125 wall is a waste where .058 is what most normal builders use
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Never relied on the bar to launch , I worked to get the balance right to get a 4" rise at the leave and carry it for 20', wheelie bar was just a safety backup that ha no influence till the front comes up 1 foot. Using .125 wall is a waste where .058 is what most normal builders use
my bad on the typo, it was supposed to be .058 wall not .125; .058 wall; 1.125 dia; 5ft long
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I'd rather carry less weight on the nose and rely on the bar more. Helps to tune for a variety of race tracks. Some of the tracks we race at are very questionable
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Greg, I agree, we just carry 47 lbs of balast on the very front of our car.
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No absolute answer, one just has to figure out what works best for their car
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Here's mine. I set it about 2" up, but mine is spring loaded so I get a little more rise than rigid ones.
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Heritage JrFuel is no allowed to run either a timed or RPM controlled shifter, driver controlled shifters only, also no delay or thottle controls.
I guess that's bracket racing, not heads-up racing.
Jon
The original never specified what class of racing he was in.
Moot point anyhow. Even if he wasn't allowed to use a shift timer in competition, he could us it in testing and work out to a point where the car launched well running it conventionally.....then remove/disconnect the timer.
No supposed to rely on the bar anyhow.
I'm not saying not to install one, just saying it's good way to gradually work your way up.
This method may not be for everyone, but I've had extremely good luck with this approach.
When I first got my car (short 140", 420 hp), impossible to launch in first. Front would come straight up.
Put shift timer on .2, behaved perfectly.
Put 100# of weight on front. Moved timer out .1 at a time. Eventually got to a point where the front would come up 2-3" at the hit then immediately settle....and that's the worst it ever got no matter how long of a shift time was used. Now I shift manually and run it out in 1st. No short shift.
I plan on running 20% next time out. Will set the timer back at .2 and work my way back out again.
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What I built.
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"Just keep the same amount of stuff on the right
as there is on the left. Seeing straight ahead is highly overrated...."
Best signature line ever.
i like the bar.
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We have learned a lot with the FED in respect to getting of the line and not trying to flip the car over in 2 seconds.Things not to do when you don,t have wheelie bars: 1)never launch a digger at full throttle on the trans brake when you have tons of compound on the track with hot temps and only a push bar to stop the car from flipping over.Make sure you have a driver that can pedal a digger properly from a 8 foot high wheelie.Set launch rpm correctly with correct chip,saves car and motor.As much as it,s great for the fans,they don,t come and give you some cash for the unreal wheelie after watching your wheels fly off,or help in the repair.PLease and in any thing I have missed,from some of the other digger drivers/owners,mrmopartech/scott
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for those running bar 2", how are you raising the bar for towing etc ? we've killed a wheelie bar wheel due to rough pits etc, would like to be able to raise it up quickly
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Since our car was built in 1997 we have used succesfully a quick-pin in the lower CM tube of our 3 tube WB. After each run on the turn-off road we pull the pin, place it a another hole to keep the WB high enough, like 2 feet , to keep it out of the way, while we also gather the chute, get the driver out of the car to tow to our pit. Of course we lower the WB when the driver is getting in the car in the staging lanes.
We have a crew member take care of the lowering and raising the WB, but of course, the driver can take on that job too, as our driver gathers up the chute while he's waithin for us the get him after the run.
I hope this helps. Photo shows the WB with the quick pin.
Jon
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thanks Jon, that's the solution we're thinking of.
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Good solution.
I do want to point out that NHRA does not allow quick push-button pins to be used in this application. I am using "solid" farm implement pins for mine, the kind with a hair pin clip.
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We have raced NHRA events for 18 years, GoodGuys, Heritage, Div 7 and National events, and no tech guy has said we can't or should not use the push button pins.
What I think is not allowed is the push button pins to attach the WB to the car. I'll check with the NHRA tech team when we race our next race, NHRA Calif Hot Rod Reunion, Oct 19-22
Thanks for asking.
Jon
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Yes, that is what I was alluding to. Sorry for the confusion. I mention this in the hope of saving some racer a hassle at tech-in.
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I can't find where NHRA mandates steel pins or doesn't allow ball lock pins. Can someone help me? I run them on my car but have never had an issue.