Wheelie bar

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by SpeedDemon, Apr 30, 2019.

  1. SpeedDemon

    SpeedDemon New Member

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    Hey guys
    Got a fast door car build in the works. Screw hemi, B&J with a converter.
    Wanted to run a single wheelie bar but builder advises dual. Haven’t gotten to meet up with him this week but wanted your thoughts.
    My thoughts were single maybe simpler to tune? Perhaps relying less on the bars to keep the car straight, and more on the suspension and wheel speed.
    Still learning a lot as the build goes on, but I’ve seen it both ways on pro mods.
    Questions:
    Does single still get used to “steer” the car? If so, how?
    Does titanium or carbon fiber have any advantages other than weight over chromoly?
    Thanks for sharing your knowledge and experiences.
     
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  2. quickcut

    quickcut New Member

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    Dual suspension door car, you have more twist from suspension .
    Single hard tail
     
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  3. jay70cuda

    jay70cuda Active Member

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    I have a single bar with a roots blown hemi. Used it with a clutch and converter behind it. The worlds quickest roots car in the 1/8th uses a carbon single bar. Mine is a steel. The biggest thing I’ve seen Is the length. Ive been as long as a 90inch bar and short as a 65in bar. What’s weird is my clutch would spike the sensor around 2000 lbs on the launch and go .980 60fts. My converter on same bar goes .940 and only hits 1000 lbs at the most on the sensor.
     
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  4. SpeedDemon

    SpeedDemon New Member

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    Jay, is there a particular reason you choose to run a single? Again my very novice experience on the subject is that when these door cars get on the bars it will “steer” the car left or right. I feel that if you used a single it would be more for just hitting the tires and not so much for steering the car. Where as a dual would have to tune for both the hit and direction of the launch. This is evident by some teams offset bar heights.
    You already have to tune the suspension and engine/transmission for whatever you using, dual or single. And as you said Jay, it was all how it hit the wheelie bar. Converter hitting bars softer with more wheel speed yielding quicker 60s sounds like my logic on this subject as well.
    It was also my understanding that as quickcut said, solid cars/funny’s runs single, door cars run dual. But, why is that rule of thumb in place for some and not others?
    I understand these are loaded questions, and can get a hundreds different reasons to run one or the other.
    Again looking for anyone who’s tried em both and why they like one or the other. No big time player, just having fun going fast. Thanks
     
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  5. jay70cuda

    jay70cuda Active Member

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    I started with a dual. My car was wicked heavy. Both bars were set the same height. I went with a single when others started using them. And it was lighter. I was a skeptic but a little bit of rear steer and we were all straight again. I have single titanium bar and a moly bar. Both seemed to work fine. Ti bar was 10lbs lighter.
     
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  6. Mike Canter

    Mike Canter Top Dragster
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    I think single wheelies are less complicated. I would stay away from Ti because the welds will crack. Ti has to be welded in a chamber filled with a inert gas and nobody does that so the welds break.
     
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  7. TOL

    TOL Active Member

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    What about these fabricated (bonded) carbon fiber bars. Are they turning out to be reliable?
     
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  8. Mike Canter

    Mike Canter Top Dragster
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    The carbon fiber ones are working great. There were some problems when they first came out but all that is now fixed
     
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  9. jay70cuda

    jay70cuda Active Member

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    What about tire shake mike? I heard that ruins those bars in a matter of a few passes?
     
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  10. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    I'm a big, big fan of the carbon bar. Not just because of the weight, but they really help the chassis/tire at launch. It's hard to make a steel bar rigid enough without being way too heavy. Wheelie bar flex is your enemy.

    With the flex bars we have run on just about every type of car for years, especially with a clutch, you dead hook it, hit the shit out of the bar, then the flex of the bar springs the car into a spin. Ideally you would keep the car in enough of a controlled spin or moving hard enough it wouldn't try to dead hook the tire and start the cycle again.

    When you get the bar stiff and right, it hits the bar once and is gone. I have found it's usually just the opposite of what you think - you have to hit the shit out of the tire to make it good like that.

    Also the longer the bar, the more leverage it has to unspring the car. The drawback of shorter is the front end can travel more for "x" height on the wheelie bar the shorter you go.

    Dual vs single - really depends on the car and how it is scaled. I think it does a better job of keeping the car from rocking over on the right rear as hard. It's not night and day better so it depends on how close you are to weight and how your chassis builder sets the car up.
     
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  11. SpeedDemon

    SpeedDemon New Member

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    Thanks for the responses. Talk to builder and he said we can run which ever I like. He did say he would rather run the dual, as he’s more familiar with that setup, but I still feel like single is the way I’m going. I noticed the MVM carbon bars have an off set to their single setup, so there must be some amount of “steering” that can be accounted for with those as well. Or maybe I’m missing the purpose?
    Thanks again for sharing the knowledge.
     
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  12. lucky devil

    lucky devil Member

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    I was just about to ask about the "Offset" single wheelie bar too. Does anyone have any experience with one , I have not seen many cars with them on yet.
     
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  13. Larry Bradford

    Larry Bradford New Member

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    I have a single wheelie bar and I made the mistake of having it to high. The car unloaded the left rear tire and turned left. No offset. FCC Denton, this year. You can watch the video to see what not to do. Larry
     
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