CLASS RACER FORUM - Brake Pressure Switch for launch control ???

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Re: Brake Pressure Switch for launch control ???

Quote:

Originally Posted by Rich Biebel (Post 701585)

The problem with that on a reverse pattern is the shifter or lever is moving toward the switch as you upshift. The switch would also be in the way going back to N-R-P

I've made switches like that on other cars but the shift pattern was forward.

I'm sure it can be done but it takes some thought and fabrication

The built in neutral start switch posted above is a good solution

With the switches I posted a picture of, I was thinking of mounting it between the pan & shifter lever, letting the inside face of the arm touch the roller on the switch lever. In this arrangement, it would only contact in low gear & wouldn't affect the lever's range of motion either direction.

I just have a push button on the back of my Cheetah shifter & the shifter contacts it in low gear (forward pattern), activating the brake pressure switch.

Re: Brake Pressure Switch for launch control ???

Slightly off topic here, but is it legal to use a momentary switch that's not mounted directly to the brake pedal that you hit with your foot? Like a WOT switch on the back side of the pedal that makes contact when the pedal is depressed a certain amount? I could go through the rule book and check myself but I'm lazy and I don't want to. TIA

Re: Brake Pressure Switch for launch control ???

Quote:

Originally Posted by JP1738 (Post 701651)

I believe something like that would be legal. That?s how a lot of clutch guys activate the 2 step, with a momentary switch, sometimes mounted to the pedal, other times activated by the Z bar, or back of the pedal. What I don?t think is legal, is having a button to activate your circuit for your 2 step. Not that tech is really a thing anymore, but NHRA didn?t like that in theory, you could also deactivate the 2 step with the same button, and in Stock you aren?t allowed to launch off of a switch or button activated by hand.
Now, I?m not sure if I?m just ignorant, oblivious, etc, but I don?t understand the issue of having a brake pressure switch active during the run. My 2 step is activated at 600psi. More than likely, if you?re using more than 5-600psi on a run, you are probably not going to be under power, and probably close to locking up the front brakes. To the best of my knowledge, if engine rpm is above the 2 step rpm, ignition will be cut completely.

Re: Brake Pressure Switch for launch control ???

Makes sense about the brake pressure switch being active down track and not triggering the 2 step because you're not applying enough pressure to trigger it....

The info I've gathered here has helped Thanks...

Re: Brake Pressure Switch for launch control ???

If you don't have some way to deactivate the brake pressure switch down track in theory it could activate the 2 step when you do any hard braking.( dumping, hard backing into, ect) Depending on when, where, and how you hit the brakes that activated the 2 step it could be said you were activating a down track stutter device. I would hate to have that discussion with NHRA Tech. Some sort of deactivation switch is the route that might be all around the best and safest.
.02 for free