traction at top end

Discussion in 'InsideTopAlcohol.com Tech Questions' started by hydrotherapy, Jun 13, 2019.

  1. hydrotherapy

    hydrotherapy Member

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    I have a altered with a 540 brad fat head with a 206d at 92% with a lencodrive 3 speed 28% and 31%, with a Goodyear 36" tire with a 4.30 gear .Looking at the computer at the last 300 ' of the track the driveshaft rpm looks like a saw blade 200 rpm up and down,have pulled 5 degrees of timing when shifted into third and no help,added more wing nothing air presure on tires from 6.3 to 7 psi. We run on tracks that are marginalat best,but this at different tracks.
    Car runs 6.3 at 218 mph 1/8 is 4.092 at 175
     
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  2. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Hard to do much with bumps on a solid chassis, especially short wheelbase altered. You can drop the front tires down to about 35 and that will help some but wing is about the only thing you can do for bumps.
     
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  3. dw901

    dw901 New Member

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    How old are the rear tires?
     
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  4. hydrotherapy

    hydrotherapy Member

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    Replaced the rear tires 8 months ago
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    I agree with Will on dropping the front tire pressure down. The front tires hit the bumps first and it is felt by the whole chassis.
     
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  6. TOL

    TOL Active Member

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    Is it slowing you down or causing you issues, or just an anomaly that you notice ?.......
     
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  7. hydrotherapy

    hydrotherapy Member

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    Were losing traction on top end and the car gets lose,the driver says that he can also fell it .
     
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  8. rb0804

    rb0804 Active Member

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    What’s the wheelbase on that thing? Am I understanding correctly that this is happening at every track you run at and in each lane?
     
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  9. Mike Canter

    Mike Canter Top Dragster
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    Do you have a wing on the rear of the car?
     
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  10. hydrotherapy

    hydrotherapy Member

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    its a 125" wheel base and yes I hane a wing on the car.
     
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  11. Mike Canter

    Mike Canter Top Dragster
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    Is it a real aerodynamic wing and is it adjustable and if so how many degrees down is it?
     
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  12. hydrotherapy

    hydrotherapy Member

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    Mike we gone from 4 to 8 degrees and no difference we also add a 1" wicker to the rear of wing,and we started with a 1/2" wicker,we also changed the spill plates with no change.
    I'm know that if you add to much wing it actes like a brake and doesn't help.
    we also moved the wing farther behind the car to give the wing a little more leveage .
     
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  13. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    If the track is bumpy, there's not a whole lot you can do for it besides lower front tire pressure and add wing. How big of a wing are we talking about? How is it mounted? I have seen some big wings and stands mounted to some flimsy tubing - so you don't want something that is going to flex rather than apply force.

    Bumps are usually what make the 'saw tooth' graph you described. If it was breaking loose at the shifts, it would be small hump/spikes right at the shifts, but usually doesn't cycle. I've seen some no prep style stuff knock the tire loose at shift and get loose but it isn't jagged; it's more rounded humps.
     
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  14. hydrotherapy

    hydrotherapy Member

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    ok the wing is solid mounted and we used areo tubing the wing is 48" by 18.5 ,we also moved it higher and back to to get it in clean air ,the wing is 2' higher than the altered body a 32 batan body we also run tubes and liners the air pressure on the tubes is 55 lbs I don't know if that make any difference
     
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  15. rb0804

    rb0804 Active Member

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    You never answered the second part of my question. Does it do this at multiple tracks and I. each lane at each tracks? How’s the track surface at the problem area? The reason I ask is if you overlay runs from two different tracks and they are the same or really similar it may indicate a problem with the car and or wing.

    Are you cranking wing angle in with a digital protractor? They can be confusing at times. Are you certain your cranking angle in it and not out of it? A poorly designed wing can also create lift.
     
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  16. Mike Canter

    Mike Canter Top Dragster
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    Hydro is the shape of the wing the same as an upside down aircraft wing. Flat on the top and bowed on the bottom with a thick leading edge tapering to a thin trailing edge. I would try more wing. Increase two degrees at a time and see if the bumps go away or the mph slows down.
     
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  17. hydrotherapy

    hydrotherapy Member

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    Our tracks are marginal at best and it does it at all tracks some worse than others ,they don't seen to prep the tracks past 1/8 mile
    We also put a stright edge on the top of the wing ,but not on the wicker and yes we do use a digital level ,but I also have one with a bubbleand they match.
    we're going to New Mexico on the 4 we will try less air in front tires and more wing and see what happens.
    Thank for all the input
    Hydrotherapy
    P/S If this was a boat I could fix it, just to make you laugh.
     
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    Last edited: Jun 18, 2019
  18. Randy G.

    Randy G. Top Alcohol

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    In the old days the Hoosier tires had a flatter footprint at speed than the Good Years. Good Years look like a Krispy Kreme glazed donut at the finish line while the Hoosiers stay pretty square with a flatter footprint. More rubber on the ground wouldn't hurt.

    Demke on Hoosiers:

    [​IMG]

    Another on Hoosiers:

    [​IMG]

    Good Years. More round and lest rubber on the ground:

    [​IMG]
     
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  19. hydrotherapy

    hydrotherapy Member

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    very interesting does hoosier make a 36" tire
     
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  20. Mike Canter

    Mike Canter Top Dragster
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    Yes they do and it is used by all NHRA blown Promods and is the best tire for them
     
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