transbrake buttons?

Discussion in 'The Comp Buzz' started by racerxo69, Oct 25, 2007.

  1. racerxo69

    racerxo69 New Member

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    did NHRA make a decision on which transbrake buttons will be deemed legal? I hate to open up THAT can of worms but id just like to know a lil in advance

    Jeff Simoneaux
     
  2. Len Imbrogno

    Len Imbrogno New Member

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    buttons

    Jeff,

    There will be a meeting during the week of the world finals in Pomona and one of the issues will be to "finalize". the button issue for both S/S and Comp.

    Len
     
  3. Pat Byron

    Pat Byron Member

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    I thought the idea of a spec button was to require a NON adjustable button. Or did I miss the point?
     
  4. Rob Harrison

    Rob Harrison Well-Known Member

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    Pat, that is precisely the point. The adjustable button thing is gone.
     
  5. Arnie

    Arnie New Member

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    Along with non-adjustable clutch linkage?
     
  6. Rob Harrison

    Rob Harrison Well-Known Member

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    Am I getting this, Arnie, adjustable clutch linkage makes the adjustable trans brake switch......even.
     
  7. DanLynch

    DanLynch New Member

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    It is called a practice tree... Hit it for an hour each night like the great ones do...
     
  8. Baltered5266

    Baltered5266 Member

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    Peter Biondo is impressive on a button, and Tim Nicholson is on a clutch....Look at Nicholson at the Denver Points meet, won the race with his WORST light being .008 I think.....I'm still having some consistancy problems with my lights, but ever since I started hitting the practice tree everynight, my lights have really come around. More practice + no more rule changes = much better comp racing. I think in the first two rounds at Vegas 50% of the races were decided by red light.....The rules don't need to be changed, drivers just need to practice, and the one's that do should have a major advantage.
     
  9. Steve Polhill

    Steve Polhill Well-Known Member

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    Tanksley, Please tell me you aren't serious...
     
  10. Baltered5266

    Baltered5266 Member

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    As for the adjustable clutch linkage, someone must know something that I don't(very likely), because I have moved mine all around, shortend, lengthend, twisted, bent, etc etc etc and have never noticed any change. I have also ran much more air gap than needed, and never once noticed anything. Maybe a clutch guru can get on here and tell everyone how to slow the reaction of the car by adjusting the linkage....I'm dying to know....
     
  11. Shane Heckel

    Shane Heckel Active Member

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    Me also.................
     
  12. Ray Vierheller

    Ray Vierheller New Member

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    I agree with Danny. We ran 20-60 air gap and I saw nothing different. Now I think that if clutch linkage is set-up wrong, it will affect reaction time, but once it's right and not bound up, you can adjust it and it won't matter. We adjusted linkage and saw nothing in RT also.

    Now, when the driver works hard to find out where the car and self needs to leave on the tree and focuses, then outside of mechnical failure, lights tend to be consistent and good.

    You have to realize that regardless of what you do, good drivers will be good drivers and bad drivers will be bad drivers. You'll see it with adjustable buttons, delay boxes, or whatever. The key to good driving is concentration. A tool is only as good as the person using the tool.

    All of the stick people griping about it, I challenge you to put any button in your car and see how easy it is. In fact, I know stick people that put a trans brake button under their clutch pedal when they've tried automatics.

    I've jumped back and forth and see little difference in reaction time with auto or stick. Until you've actually done the same, it's all speculation.

    Ray Vierheller
     
  13. Rob Harrison

    Rob Harrison Well-Known Member

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    Leverage and Gap

    .050 gap to .100 gap is definetly a change that would affect RT. Move the pivot all the way down or all the way up, is a huge change. If you hook your car up to a tree, you'll see. This being said, a button is easier .
     
  14. Ray Vierheller

    Ray Vierheller New Member

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    Rob,

    So you're saying that the increments of moving airgap 50 is more difficult than adjusting a button?

    You just hurt your own argument by showing us how adjustable a clutch car can really be. If you can adjust your airgap and we can turn some screws to get more or less button, what is the difference?

    Ray
     
  15. Rob Harrison

    Rob Harrison Well-Known Member

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    As you said...with a good driver....nothing. I was answering the clutch linkage question as to adjustability and when I drove with a button, I still maintain it was easier and there was no adjustment on the button. As far as adjustable buttons go, if you can't let go on the top bulb, by all means, leave them adjustable. If the only adjustment is your RT to the last bulb, then there is absolutely no difference. As I have never so much as pushed one, How adjustable are they?
     
  16. Baltered5266

    Baltered5266 Member

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    I must be extremely inconsistant because I have run .035 air gap, gone up to .125 and saw almost no difference. Tried this several times with the same result. I'm not understanding how "leverage" has an immediate effect on reaction time. The throwout bearing is sliding along a horizontal path being guided by the candlestick in the bellhousing. That will never change, adjusting the linkage and changing the leverage will not change the length the throwout bearing needs to travel given it always slides along a guided path. Lets say the facing of the throwout bearing is positioned .250" from the levers on the clutch. It must travel that .250" plus another (lets just say .100") for airgap. You can adjust the leverage all you want but the throwout bearing still needs to travel exactly the same every single time given the air gap and gap between bearing/levers is the same. Reaction of the clutch is determined by the amount of force applied and the immediate response in the opposite direction. Whether its easier or harder to push the clutch based on leverage wont have any effect due to the fact your not changing the static weight on the clutch and/or the distance the bearing needs to travel.....Someone correct me if I'm wrong, but that is how I see it.
     
  17. comp 670

    comp 670 Active Member

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    On a .400 pro tree,adjusting the clutch linkage made a big difference in my car...On a .500 full tree it makes no difference for me.Air gap didn't seem to make as big a change as adjusting the lever raito.But it did change my reaction time a little bit.

    Adjusting the lever raito of the linkage makes it so you can release the clutch faster because the pedal moves a shorter distance.When I tried prostock my lights went from .460 to .410 just by messing with the linkage.

    In comp with a full tree I don't think it helps much to work with the linkage,you just have to pick a spot on the tree and let it out at the same time everytime..

    Here...I'll open a can of worms..I wish comp was a pro tree...:eek:;)
     
    #17 comp 670, Oct 30, 2007
    Last edited: Oct 30, 2007
  18. Rob Harrison

    Rob Harrison Well-Known Member

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    In an exaggerated example, if the total travel of the pedal was 6" in one setting and 12" in another setting, the increase in travel would slow the initial hit of the disc, simply because your pedal has further to travel. The one part of the leverage discussion that has been left out , is the length of the clutch fork from the pivot to the linkage hole. That change would directly affect "the distance the bearing needs to travel". I am by no means the most qualified to answer this question and if what I have explained, makes no mechanical sense, then let's hear from someo who can explain it better. We have experimented extensively over the years and most of it was done without the driver knowing about it. The results were then viewed by the crew and the felt there was relevant data gained.
     
  19. Baltered5266

    Baltered5266 Member

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    By adjusting the pivot point, all your doing is creating a smaller or larger gap between the levers and the throwout bearing. It's a given you need around .250" between the two so the levers won't engage the bearing when the clutch is released. If you had 10 inches between the levers and bearing, and you had to press the pedal down 2 feet before it contacted the levers will this change your reaction? I would say absolutely not because the clutch is still being compressed the same amount depending on the amount of air gap. The reaction of the clutch is determined by the amount of force being applied(the static pressure aka base) and the distance the plates need to travel in order to lock up. I just don't see how the clutch knows what leverage point is being used to compress it. For example, when you change a valve spring, some guys use a handle that is 2 feet long, others using one that is 8 inches long. The one 2 ft is much easier to compress the spring, but the spring doesn't know what is being used. Put a handle on your spring tester that is 3 ft long and you should still get the same reading in regards to seat pressure.

    Rob, on another topic....Would adding air gap to the clutch slow down the reaction or speed it up???? It allows more distance between the plates but on the other hand as the air gap increases, the energy stored in the springs increase as well because each spring is being compressed more. I would believe the more air gap you run(which compresses the springs more) would build more energy and the spring would "rebound" much faster at the release of the pedal. I hope you can understand what I'm saying, maybe an engineer needs to get on here and set us all straight......Anyone?
     
  20. comp 670

    comp 670 Active Member

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    If you change the linkage raito so you have to move the pedal farther to work the clutch your reaction time will be different.

    In my car,moving the linkage between different holes can change the pedal travel by allmost half...So if I set it up to move only half the distance it was before my reaction time will be quicker.

    I've done this many times when racing heads up on a pro tree..I have 5 adjustment holes in each arm,one set of holes off the clutch pedal,and one set of holes off the arm on the cross shaft(my car has a cross shaft,not a fork)and by useing different combinations of holes I can usually get my light down to consistent .410's with no fear of redlighting.

    I am talking about moving the linkage points...Not moving the pivot on the fork..
     

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