Clutch settings for Aussies

Discussion in 'PSI Superchargers Tech Questions' started by Bob sherry, Dec 8, 2017.

  1. Bob sherry

    Bob sherry Member

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    Gday from Australia , well the time has come for us to run our blown alcohol funny car and we are wondering if we could get some help in clutch settings. The car is a 2002 Myer chassis with a Pontiac firebird looking body, we have a 565 cui big block chev with 400 cc dart heads and a 90 percent over B rotor PSI blower . The clutch is a triple plate 10.5 inch crower pedal clutch , the clutch is second hand with a titanium hat and the plates are the normal compound not the real grippy ones , I think you call them 91s. Everything is machined and nice and straight. The class we are going to run is called super charged alcohol which is a dial your own and no faster than 6.5 ET, the motor is a proven runner and I myself have driven and set up two different top fuel cars and many other classes , the boys that own the car have many years experience in racing as well . We have no data on the car as yet so we have to do it the old way for now. We have a 4.3 10.5 inch strange diff and 1.31 and 1.34 lenco ratios , we are wondering if anyone could give us some clutch settings as a starting point , I know it's a big ask there are so many things that come into it but we have to start somewhere, we don't intend to rev it more than 8500 for this class . Your help would be greatly appreciated. Yours truly Bob Sherry.
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    This would be a good start off setting not sure how much power you are making. Have 3.5 to 4.5 turns on base (start off with 4.0) and 24-26 grams on the fingers. Watch for the hook on the driveshaft trace right after launch and if it is too much then add a small amount of weight on the fingers until it smooths out. Also the clutch should lockup in high gear one second after the shift into high. Add finger weight to lock it up. This should result in a lockup in second gear one second after the shift.
     
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  3. Bob sherry

    Bob sherry Member

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    Thanks Mike I appreciate your info , we don't have a data computer yet but you have given us a good start , do you have a recommendation on air gap ?
     
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  4. Mike Canter

    Mike Canter Top Dragster
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    .065 to .085”. I would start with the wider gap and work your way down until the car starts to creep and you can still hold it then go a .005” wider from that point so it does not creep and you can hold it at staging rpm.
     
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    Last edited: Dec 8, 2017
  5. Bob sherry

    Bob sherry Member

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    Thanks mate your a big help
     
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  6. Mike Canter

    Mike Canter Top Dragster
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    Since you don’t have a data computer then if it looks like the car is running well then add 2 or 3 grams to the fingers and see if you mph gets faster or slower. If it slows down then go back to where it was and take off a couple of grams and see if you get faster or slower. Let me know how it goes
     
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  7. Bob sherry

    Bob sherry Member

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    Thanks mate priceless information
     
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  8. HootersFunnyCar

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    With only 8500 RPM you might want more counter weight maybe 34 grams. What launch RPM are you planning on? That will help determine the air gap.
    Like Mike said 3.5 to 4.5 turns of base if your using the double spring.
     
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  9. Bob sherry

    Bob sherry Member

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    I thought we would try 4,500 launch Rpm first , and we have the single spring only. We have a dial indicator to set the ring height which is about 805 thousands.
     
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  10. Mike Canter

    Mike Canter Top Dragster
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    Unless your track is very bad I think I would launch at a higher rpm maybe 6000 to 6200. You can try the 4500 and see what happens. Somebody out there correct me if I am ring but the ring height should be .702” Hooter the reason I didn’t go up on weight to 34 grams is that I don’t that BBC with a Roots blower is going to make the power of a hemi with a screw blower. So maybe somewhere between 26 and 34 grams.
     
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  11. Bob sherry

    Bob sherry Member

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    We have a 90 over B rotor PSI Mike , I'll measure the dial gauge setting to see what it actually is and let you know . I'll rev it if I have to no problem Mike.
     
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  12. Mike Canter

    Mike Canter Top Dragster
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    Lol, my memory is failing. But still a BBC vice a hemi
     
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  13. Bob Meyer

    Bob Meyer Comp Eliminator

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    G'day Bob; you have recently become famous here in the States, due to your "traction checking" machine :) !!!
    First......it's spelled Meyer ! Second.....the value just went up, it's a 2004 car !
    As those boys know, I will help all I can (forgot to send invoice for front mount).
    Please check clutch lever thickness, what size counterweight bolts (either 1/4" or 5/16"), stud & stand size, and if scalloped or round flywheel.
    Then email to: meyerracecars@sbcglobal.net
     
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  14. Bob sherry

    Bob sherry Member

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    I’ll keep you informed of how we go and see if we can get this puppy down the track , thanks again
     
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  15. Bob sherry

    Bob sherry Member

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    No worries Bob will keep in touch , do that in next couple of days , and if you want to order a Bung Of Fritz traction machine you will have to go through my distributors LOL
     
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