Is this ever done?

 

does not work that way

 

I was looking to do 4 wheel line locs with a 2 step so that i can leave off of a button. Do the line locs have to be before or after the proportioning valve?

 

It is effective enough that NHRA specifically banned four-wheel line-locs in Stock Eliminator (see page 118 of 2009 Rule Book). The General Regulations make no mention of it, however. I would guess that, if you have really good brakes, you could hold a car on the starting line up to about 3000 RPM. It will torque load the chassis unlike a trans brake but I'd think some experimentation would prove or disprove the effectiveness of the theory.

c

 

He speaks the truth. I tried it. It was a waste of $125.

 

NHRA Sect 19 3:1 also specifies that if the vehicle has a differential pressure switch for the brakes, the solenoid must be located after the switch. I know the LT1 ABS setup uses a combination pressure differential switch/proportioning block. Not sure if the LS1 ABS unit is similar.

 

The only way I could spool up my torque converter was to pump the brakes as hard as I could then hold the park brake, and the tires still spun over 2400rpm.

 

A two step should allow you to brake stall higher then without since your not making as much torque. The only reason i want line locs is so i can leave off of a button. The button would activate the line loc and two step, mash the brakes .... hit the button....... remove foot from brake...... pin the throttle.... release the button.

What was your experiance malice?

 

i wouldnt do it if it were me...

 

im just using a line lock on the front brakes and have the 2 step set at 2000 it works quite well actually

 

this is an old timer trick from the super stock days. with the rear wheels locked down and use a 2 step set the 2 step 500 to 1000 rpms below your stall speed . great idea to use same button . if you have your frame tied together it will make the car 60 ft better. in a car with a trans break it is always good to 2 step it about 1000 rpms less so when you leave it will flash your tc.

 

You cannot say it will make the car 60' quicker.....

every car is different, with a good converter it will make it worse if the chassis is not loaded. some converters like to be flashed, some like to be loaded or stalled.

The only advantage I see is if your a button racer vs. a footbrake racer.... but even if you are a button racer I don't see this as a good way of going about it..... so much of this stuff is trial and error, some thing work for some cars or drivers and some don't. I am a biased footbrake racer

 

If you are planning on doing this in a points type race and you are running in the footbrake class, check you track rules. At Maple Grove in the class they call Pro Eliminator "rear wheel line locs" are prohibited and a "two step is allowed as a high side rev limiter only."

 

IMO It ain't going to work. You can only footbreak (linelock, emergency brake, stand on the break pedel) so much before the car will spin the tires an or roll forward. A trans brake puts the car in first gear and reverse at the same time. Press the button and the trans brake engages (first and reverse) then you can mash the gas to the floor. The car will stay in place and rev to the max stall of the converter. In my case that's 4000 RPM. If you wire a 2 step you can set your launch rmp to something lower than the max converter stall. Example in my case say 3000 RMP. The max rpm that I can footbrake the car is 2200 RMP. When you let go of the button the car launches like a clutch dump. If you want to launch off a button get a trans brake. Side note is that the trans builds a tremendous amount of heat when the trans brake is engaged.