Clutch-Counterweight Distribution

Discussion in 'PSI Superchargers Tech Questions' started by Tob, May 19, 2005.

  1. Mike Canter

    Mike Canter Top Dragster
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    I really do have to agree with Bob. With that kind of overall first gear ratio it is going to be real hard on the clutch and hard to tune. One car I work on has a total of 8.42 and the other is around 9.0 but that one is a heavy car.
     
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  2. M Tigges

    M Tigges TAFC

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    Bryan you need at least a 1.75 low gear with a 4.30. if you dont run a leaner through low gear a 1.80 to 1.84 first gear.
     
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  3. bryanbrown

    bryanbrown Member

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    Thanks for the help. I think now we can get close and then fine tune from there. I really appreciate the advice.

    bryan brown
     
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  4. Crew

    Crew Volunteer

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    Man this is a good topic! How does this info compare to a PSI/Hemi BAD with a 10" big stand alum hat?

    Crower sent me my clutch with 5 turns of base (i'm guessing the 10.7 clutch has a higher spring rate with on 2-3 turns). I looked at the booklet Malinari sent me and it says 28g of total weight.

    1.64 low x 4.30 rear.

    Im looking to get a bit more aggressive than the "factory setting" since my 60' are down.

    In what steps should I apply more weight or turns of base? Can someone explain what only giving base will do?

    I'm new and trying to sponge all this in!
     
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  5. Tob

    Tob Jr. Dragster

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    Crew, the 'factory' setting on our Crower was 3 turns.

    We're a newer team, so we're not real smart on this stuf yet. Generally, our National event setup is significantly different than our Divisonal setup. If our Divisional baseline is 3 turns and 16 grams, then our National event setup might be closer to 4 turns and 32 grams. (general #'s for reference points, not specific-don't assume these are good tuning #'s) NHRA races, so the track prep and quality of surface is very different between National and Divisional.
     
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  6. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    crew,

    if you're looking to get more aggressive in the first 60', put more static in it. you can get up to about 6 1/2 turns in it, then when you take the washer off the jam nut, you can get about 7 1/4 turns in it.

    static is your intial plate load when you swap feet. contrary to the belief of some, static is with you all the way down track. i've heard some people try to tell me that static was just like the barrel valve setting, just for launch purposes, and had no relevence into the run. had to disagree with them there. also, by loading your motor, it makes the counterweight come in later, and in some cases to a more advantagous part of low gear. if you dont have enough static, the motor runs away, thus it makes the levers come in sooner than if you had grabbed the motor more with static.

    as you can probably tell, i like static. i'm still looking for the static screws on the converter in the funny car.. :rolleyes:

    uncle bob: this is a serious question...so don't take it as me arguing your point. i worked with mike kosky in atlanta, and he doesn't change/grind the discs every run like you say. since you have experience with this, at what point do change them out? if clutch wear becomes uneven? do you compensate with minor adjustments per run and/or when you put a fresh or new pack in it?

    i'm just curious. mike's car ran fairly consistent that weekend doing that. i'm used to the complete opposite. on cannon's car, the discs came out and we ground the same discs until they got too thin, then replaced them with a new one, and compensated by treating it like 2 grams extra on the clutch with a new disc. the theory is to have the same discs in as much as possible, and go into the run with a fresh ground surface.

    just looking for some insight..
     
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  7. d johnson

    d johnson Top Alcohol

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    we have a crower small stand 10" clutch in the dragster and was wondering were to start and be as safe as possable on the set up 451" BAE 3 speed lenco psi 4.30 gears first gear i think is a 1.58 or 1.62 will knows the gear in it, i was thinking about 3 turns of static in at a base of .708 and counter weight of 12 gms per lever thats my thought, share yours thanks
     
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  8. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    nowhere near enough static for a dragster. put more static in it. you have a 1.60 trans. put 5 turns in it to start..
     
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  9. Tob

    Tob Jr. Dragster

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    Now my curiosity is really peaking-6-1/2 to 7-1/4 turns in a TAD(assumption)!!

    As I mentioned earlier, we've just begun to really throw clutch at our TAFC after 10-12 races in our backpocket. So far, she won't hold much more than 4 turns on a really, really good track. On a poor Div. track with so-so air, we really have to back down the static turns and counterweight to get it off the line. We've run .970'ish 60 ft. times and qualified in the top 1/2 in the past 4-5 races. So far, our general clutch setup looks to be really light, though, compared to what I am seeing in this discussion. I hope we're not missing something obvious.

    Question for clarification: 1.) Is there any relevant comparison between TAD and TAFC for static and counterweight? I apologize if this is a stupid question, but we have no TAD experience and it seems to me that there isn't much relevant comparison, the TAD handles a much more 'aggressive' setup from what I can see. 2.) What are acceptable setup tolerances for most teams, regarding clutch install?

    Great discussion, thanks to all involved.
     
    #29
  10. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    to run a lot of static in any car you have to run tall gears. if you dont have alot of static in it and you try to run a taller gear, the motor just runs away from the clutch because there isn't enough clutch. then when the motor runs away, the counterweight comes in sooner. usually when this happens...it doesnt have enough wheelspeed, then the counterweight slams in, then it trys to gain wheelspeed too quickly. had you had good wheelspeed initially, the track would probably handle that 'x' driveshaft rpm at 'y' seconds, but it was too much of an increase in a short amount of time...

    i have very limited experience working with a screw blower fc with a clutch. there's one clutch set up thats right for all cars. but if you put more static in it and it smokes the tires, put a taller gear. you'll be able to get away with more counterweight on the div tracks.

    just gotta do what the car tells ya.
     
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  11. Alkydrag

    Alkydrag Sr. Dragster

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    Just keep in mind, the more power (torque) you're making, the less clutch you'll need.
     
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  12. Gerry Woz

    Gerry Woz Comp Eliminator

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    Alkydrag...

    I think you have half of that statement right..I think you want to give it all the clutch and power the TRACK can take...if the track can't handle the motor going 1:1 sooner, thats when you pull clutch or kill horsepower or both, to get the car down the track...you might as well use that EXTRA power you are making instead of slipping it away by too light a clutch [​IMG]
     
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  13. Alkydrag

    Alkydrag Sr. Dragster

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    Woz, your absolutely right. Let me add a little bit to that. If your only making 2000 horsepower, you need more clutch than if your making 3000 horsepower to get the same reaction. But obviously you'd like to give it as much clutch as the race track can handle. By the way, do you guys need some help, I'm just around the corner.
     
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  14. d johnson

    d johnson Top Alcohol

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    i look at the clutch and what i see if i am right,the more static you run will get you off the line and down the track a ways but you need counter weight, to me you need static for 60' the more you run. the more you run the risk of smokeing the tires counter weight will give you mph and help lock the clutch up. if you run lots of static and the track aint that good you will spin the tires and counter weight will take over and thats not good. thats my thoughts
     
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  15. Crew

    Crew Volunteer

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    This may be for another topic, I have seen a car be running well but they decide abandon that tranny ratio & clutch setup for a complete different deal. If I remember right they went from a 1.64 to a 1.58 and threw less weight at the clutch and improved.

    What would the reason for this be? What would signify that a change like this would improve the car?
     
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  16. Bob Meyer

    Bob Meyer Comp Eliminator

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    uncle bob: this is a serious question...so don't take it as me arguing your point. i worked with mike kosky in atlanta, and he doesn't change/grind the discs every run like you say. since you have experience with this, at what point do change them out? if clutch wear becomes uneven? do you compensate with minor adjustments per run and/or when you put a fresh or new pack in it?

    Will; I've been away playing (old)human on an Alaskan cruise deal for 2 weeks, too cool !

    As you know, I'm pre-computer, so a lot of this was learned the hard way. The computer is certainly a god-send, but, remember I burn metal for a living! I know what color it turns when it gets too hot! If the floaters (which I DO believe in grinding) get real blue down to the center, you are way too light on static. To turn the tips blue with a slight bit of warpage, I'd simply turn them backward and add 2 grams per finger.
    Once you get to this point for a baseline, you can generally run 5-6 runs without pulling the can!
    Of course you have to be able to read what it's telling you, what the track, sun, humidity, National or Divisional rubber, and most important, if you are holding your mouth right! Then you make the changes, per run/day the car or track tells you it needs.

    The numbers I think you want are: .285 thick/88 B for the discs and .325 for the floaters. The old days .250 floaters (new)were easy to learn from, but were a pain in the _$$.
     
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  17. J Shafer

    J Shafer New Member

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    Does anyone here have access to plate load / torque capacity math related to a typical TAD/TAFC clutch?
     
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  18. D. Palmer

    D. Palmer TA/FC

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    Bob, I'm curious are you saying that .285 is the minimum thickness you run discs and .325 min for the floaters? I have always been told .270 was a good minimum number for both discs and floaters as long as there is sufficient hub clearance in the assembled pack. Thanks! Doug
     
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  19. Bob Meyer

    Bob Meyer Comp Eliminator

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    Doug; maybe it's just coincidence, but usually by the time the discs get to .285 they have turned to stone (over 88 B Rockwell).
     
    #39
  20. Bob Meyer

    Bob Meyer Comp Eliminator

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    Will;
    I would just like to throw something out here for all to think about, I also am not trying to be a smartass knowitall, but am enjoying the openness of the conversation.

    At 6.5 to 7.25 turns, do you think the springs are close to coil bind ? Would you run the motor with the springs close to coil bind or go to stouter springs ? This is my question, anybody got thoughts ?

    If I were you with that converter, I think I'd be tickled to not have those knobs to fiddle with!
    Maybe I'll get to find out next year! (if Gary will let me hang out).
     
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