Changing tire sizes?

Discussion in 'PSI Superchargers Tech Questions' started by Brent, Mar 25, 2008.

  1. Brent

    Brent Member

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    I'm looking at going from 34.5-17-16 to 36-17-16. 526" TFX, 3 speed Lenco, 3 disc clutch, shift at 7400, 7600 in the lights, 6.70s @ 200 match race car.Is this going work or am I looking for trouble?
     
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  2. mark6052

    mark6052 Member

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    I have run a similar combination. I ran the 36s for more ground clearence. but got tired of trying to find good used slicks of the same compound. they were hand downs of fuel cars. goodyear hasnt really made a tire for alcohol. Im back with hooziers, its easier for me to get good used low run tires at cheap prices.
     
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  3. tranman

    tranman Member

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    we have similar combination as well. its a spitzer car 526 BAE/TFX stage 5 head. we run the lencodrive 3 speed shifting 8000 and 8200. 4.30 gear because were mainly 8th mile racing. we ran an 8-71 mainly but switched to a 16-71 for a match race. anyways at world series at cordova we ran 6.38@ 215 after we changed to 36" goodyears and the 8-71. We had alot of trouble with 34.5's in 2nd gear shift, knocking the tires loose, especially when nightfall came around. Tried different 34.5's (mickeys, hoosiers, etc.) and even tried some fuel management to drop power during shifts and it helped but due to not having enough test time between races we threw 36's on and it LOVED it. Believe it or not we got down the track on nights when bracket supercomp cars couldn't. (narrow groove and dew setting in) Only trouble we had which i think was a chassis issue was at launch it liked to roll the back end of the car more to the left and set the front end down to the right. Tried different power levels and didnt' make a difference.
     
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  4. 359PETE

    359PETE New Member

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    I ran 34.5 's goodyears on a roots and still do @ more rpm less mph. I've went to a psi screw and thinking going back to 36 's. For me on a match race deal it's nickels and dimes for et's & mph. Just fuel for thought. John
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    Brent, you didn't say what rear gears you are using? One of the big questions is if you can get the RPm in 3rd gear without slipping the clutch too much. Yep, it will be less impact shifting to second gear because the final gear ratio has changed. It is a combination package and it may take a little time to get everything working. It may take a little more base and finger weight to get to the same point.
     
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  6. Brent

    Brent Member

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    Mike,
    The rear gears are 4.11 with a 2.24 and 1.44 2nd in the Lenco. The way I see it I'll be losing 300 rpm in the lights? I still have some room to move on the Hi spd.
     
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