potential hazards by holding brake while gassing?, talking about an automatic Options

[daazndood]

hey guys. i was wondering if it would be bad for a car if i were to hold down the brake and gas at the same time , sorta like to launch the car by releasing the brake.

i noticed that i can go 0-60 in 10.2 seconds if i just step on the gas alone, but if i hold down the brake and rev the engine to about 2k(thats highest i can keep it before it starts moving) and release the brake i can hit 60 in 9.4. i was just wondering if i am hurting my car. i really dont do this that much and i dont try to race or speed anyways. thanks guys

[Daftboy]

I don't belive so...your brakes might go faster but I don't see any harm in this .....then again i could be dumb...:lol:

[Kadett]

Auto or Manual.

In both cases I wouldn't do it to often if I were you. To many wear&tear on brake en drivetrain parts.

[DSRT-FX]

with the technique you've mentioned im pressuming your car is auto. i wouldnt do this to the car. its puts too much stress on your brake and drivetrain parts. you'll slowly and surely end up with problems. -R

[chandy1986]

i've done that a few times with my 5spd but i got a whole nother reason for doing that. trying to smoke my tires not even sure im doing it right but i can smell the auroma of burnt rubber. i know its bad and not good for the car so i rarely do it

This post has been edited by chandy1986: Sep 14, 2006 - 7:45 AM

[neKronos]

I believe this is referred to as break torquing?

"In general, automatic transmissions are known as being more useful for lazy commuters than for hardcore racers. But it may be surprising for some to know that many 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. Instead of a sudden massive load, the drivetrain has the torque applied slower instead of one huge jolt.

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."
- http://www.modernracer.com/tips/dragracing...techniques.html

[Shocker]

i do somthing like this somtimes...i hold the e brake..press in the clutch and give it gas and when they say go release the cluth and drop the brake at the same time.

[daazndood]

I believe this is referred to as break torquing?

"...This is because the automatic transmission absorbs the shock by design, and brake-torquing actually reduces stress on the rest of the drivetrain. Instead of a sudden massive load, the drivetrain has the torque applied slower instead of one huge jolt.

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."
- http://www.modernracer.com/tips/dragracing...techniques.html

my tires actually did spin like crazy, but probably cuz i need new tires. lol.

so this article is saying that it actually wont hurt the car? im confused. and whats power brakes?

[lagos]

its REALLY bad on your automatic tranny. if u do it, expect to have to replace the trans not too long after.

[devilsden97]

I did that at the track at the DWG meet. Held the brake pedal to the floor, with the gas pushed to the floor. The car reved to 2.5k and stayed there. Green light, droped the brake, and took off.

no problems since....::knocks on wood::

[Bitter]

ive done it many of times with no damage, just dont hold against the tq converter for more than 5 seconds. as a matter of fact, what you do is a diagnostic procedure in the service manual, just minus the launching part.

worst case, you break a weak axle, cv joint, or sheer a pressure plate bolt. but at stock power levels thats VERY remote. just dont nuetral drop it!

heres a little how-to from another site that i wrote

1. Find your stall speed.
a. In an empty parking lot, or somewhere desolate, put one foot down HARD on the brake pedal and then slowly apply the gas pedal until the rpms come up and stop rising. that is the stall speed that I will refer to later.
b. write this number down, mark it on your guage face with a non permanent marker, or memorize the needles position. you will need this later.

2. Practice.
a. Using the 2 foot technique (one on gas and one on brake) determine the amount of brake pedal pressure needed to hold the car in place with the engine at the stall RPM.
b. Now with your foot on the brake with the needed amount of pressure slowly raise the engine RPM to the stall, then drop back from the stall by 200 RPM.
c. Finally, this is the tricky part where you need cordination. Release the brake pedal WHILE mashing the gas. the 2 actions have to happen at the same time, if you bounce off the stall your launch is ruined.

3. Experiment
a. Find at what engine rpm you feel like you get the best launch from. different cars with different mods have different power bands. some may launch the best right at stall while others may do better several hundred rpm below stall.


there, now you know how to launch an automatic, or atleast how i was (self) taught. will you get the tire smoking burnouts that a 5spd will? nope. will you get slightly better 60ft times? maybe

This post has been edited by Bitter: Sep 14, 2006 - 11:37 PM

[94celicadude]

not an expert and not trying to be one, but i do know that it will cause your torque convertor to heat up very quickly, and if you do this repeatedly as others have said, bye bye torque convertor. So try to stay on the low down witht hat move , unless you dont like ur drivetrain.

[Bitter]

yea, dont do it repeatedly all the time on a hot day lol. its ok to do at the track with cooldown periods, or from a street stop if you're just playing around. having a trans cooler is very beneficial when you're doing these things as well.

[sinner96ST]

it's just generally a bad idea.

a lot of strip racers who want good staging practice usually get this thing called a 'line lock' which basically locks the brakes on the front, while they do burnouts with the rear wheels. this allows them to heat up the tires, giving better grip off the line. or just to do a nice burnout.

you're trying to lock your brakes with the same wheels that are providing the power - not a great idea. don't do it, if you want a faster car, sell your 6th gen.

[coldbluesteel]

My celica's 5 speed so I dont do it, But my 4runner is auto and I do it all the time. We call em brake stands, hold the brake give it some gas, and the truck growls and hops up a few inches. It's the same way I do burnouts in it, hold the brake and give it more gas! I don't do alot of burn outs anymore cause Nitto 305/40/22's aren't cheap!