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TRANSBRAKE?

Discussion in 'The Garage' started by CHEVY 4WD, May 22, 2003.

  1. CHEVY 4WD

    CHEVY 4WD 1/2 ton status

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    I know this isent a very popular thing in the 4x4 world but Im still very intrested.
    But I want to know how they work, if they are horibly bad on trannys and if you can even get them for a 700R4
     
  2. HarryH3

    HarryH3 1 ton status Author

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    They work by locking the tranny into 2 gears at once, so the output shaft can't turn. /forums/images/graemlins/eek.gif They're only useful for launching off the starting line in drag racing. The racer typically hits the transbrake switch after setting the staging light, the switch may also activate a rev limiter. Then they push the throttle to the floor, with the engine bouncing off the rev limiter, usually just below the stall point of the torque converter. When the green light comes on, they just hit the switch and it instantly releases the transbrake and goes to the 2nd stage of the rev limiter (the true redline now). The engine revs like mad, the torque converter fully engages, and all hell breaks loose as the car launches violently !

    I don't know if they even make a transbrake for a 700R4, but it would be pretty useless anyway unless you intend to build a full-on race engine, with something wild like a 4,000 RPM stall torque converter, and go racing. /forums/images/graemlins/eek.gif
     
  3. CHEVY 4WD

    CHEVY 4WD 1/2 ton status

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    Do they use them in sand drags? What 2 gears does it put it in to?
     
  4. Lonnie

    Lonnie 1/2 ton status

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    Generally the engine is loaded against the converter when on the brake.... not the rev limiter. This way the full stall speed of the converter is being utilized. It locks the trans in 1st & reverse at the same time. They are very hard on driveline components & trans life is reduced as well. The design requires a full manual valve body & usually does not have any compression braking features... meaning that the engine returns to idle during coast & the engine will not slow the vehicle in 1st or 2nd gear. They are not intended for street use (due to high fluid line pressure), but do have their place in drag racing. As for sand drags, it is possible, but not sure it is an advantage with the already limited traction of sand. I'll save that one for someone with sand drag experience.
     
  5. 83ZZ502_Jimmy

    83ZZ502_Jimmy 1/2 ton status

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    Yes they do use them in sand drags. But to use them you cant run a street class normally. It is reserved for the modifed classes.

    When you run a Transbrake you must also install a scattersheild or tranny blanket. I have seen a couple explode, its not pretty /forums/images/graemlins/eek.gif

    I personnally would not run one on a 700R4. A built T-400 or powerglide is the only ones that I've seen them on that last.

    I have raced a buddy's truck with a transbrake and it has a CO2 shifter and RPM limits for each gear. For sand racing you have to have an air shifter in a fast truck b/c there is not much time to shift while your driving /forums/images/graemlins/smirk.gif in a fast truck

    John
     

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