Brake torque
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Brake torque
I am planning on goin to the track to get some baselines before the turbo and I remember reading on here someone saying that if you hit the gas and brake at the same time while in gear the car sort of goes in limp mode. Is this for all z's or just automatics? I have a mt6 and I dont want to try and do one before staging and look like an idiot. If this is in fact the case I guess I'll just have to drop the the clutch a little bit just to get them to spin a warm up just a little bit.
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Originally Posted by 1 2 NV
I am planning on goin to the track to get some baselines before the turbo and I remember reading on here someone saying that if you hit the gas and brake at the same time while in gear the car sort of goes in limp mode. Is this for all z's or just automatics? I have a mt6 and I dont want to try and do one before staging and look like an idiot. If this is in fact the case I guess I'll just have to drop the the clutch a little bit just to get them to spin a warm up just a little bit.
... pro drag-racing cars have heavy-duty auto gearboxes. That's because the brake-torque launch is an automatic specialty. This launch involves keeping the car stationary by flooring the brakes with the left foot, while using the right foot to rev up the engine against the torque converter. In technical terms, this preloads the entire drivetrain with the stress of a launch, allowing the engine to rev closer to its power and torque peaks at the starting line. Brake-torquing is also beneficial for turbocharged engines as it allows boost to build up before the launch, reducing turbo lag. The only problem is that there is a lot of stress on the transmission, and the consequent heat build-up can destroy your automatic gearbox. Unless your car has too much power for the tires to handle, a brake-torque launch usually will not spin the wheels. This is because the automatic transmission absorbs the shock by design, and brake-torquing actually reduces stress on the rest of the drivetrain. Proper brake-torquing will have a catapult effect, immediate torque multiplication gradually traded for velocity until it couples or the next shift occurs.
If your car has power brakes, you could apply the brake-torquing technique even better. At the starting line, shift your auto gearbox into neutral and floor the brake pedal with your left foot. Rev the engine once and quickly get off the throttle. You will feel the brake pedal sink further to the floor. This greatly increases the braking force. Now shift back into gear. You will now be able to rev up the engine even higher against the torque converter.
If your car has power brakes, you could apply the brake-torquing technique even better. At the starting line, shift your auto gearbox into neutral and floor the brake pedal with your left foot. Rev the engine once and quickly get off the throttle. You will feel the brake pedal sink further to the floor. This greatly increases the braking force. Now shift back into gear. You will now be able to rev up the engine even higher against the torque converter.
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Originally Posted by r34 racer
I'm not aware of any limp mode, but be aware that the ECU will cut throttle response to 20% of its power (or some obscure figure which i have forgotten) while the brake and gas are applied simultaneously. Supposedly this helps with heel-toe downshifting.
Heel-toe downshifting isn't necessary on most modern ATs because they have computer-controlled clutches and/or a torque converter. The Z 5AT has both.
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Originally Posted by 1 2 NV
I am planning on goin to the track to get some baselines before the turbo and I remember reading on here someone saying that if you hit the gas and brake at the same time while in gear the car sort of goes in limp mode. Is this for all z's or just automatics? I have a mt6 and I dont want to try and do one before staging and look like an idiot. If this is in fact the case I guess I'll just have to drop the the clutch a little bit just to get them to spin a warm up just a little bit.
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