using dual line locks

or your the brother that won rock,paper.scissors and get to drive

LOL...
They are usually not legal, especially the version pictured!

Although I agree with you...does anyone know why Dual LL are not legal?...and not the ones that hold your bumper.

That's awesome.
The pavement in front of my parents house looked like the staging lanes at Northstar dragways from us and our friends.
If your car couldn't do a proper burn out , there was usually a few volunteers who would hoist the back of the car up high enough to get them spinning.
Then , we discovered alternative uses for drain oil.
A six cylinder '70 Mustang looked like the Blue Max heating the hides coming out of that stuff. LOL

My understanding is that they are not legal in Sportsman/Footbrake classes because they are a "poor man's" transbrake, and can also be used with a hidden box....

25 years ago when a guy in the shop said his car would not spin the tires, a local said all you need is HOLESHOT GRAVEL!

I tried it long ago. Released way to slow, worthless.
Doug

Used it from 1985 until 1995. Worked great with a delay box, 2-step, soft touch. Weak link was, and will always be, the driver, me.

I used the two line locks, for the front I had a rectifier out of an alternator so as not to energize the back brakes. Worked great with two step and delay box at 3000. Later on when trans brakes came out I switched. Also tried the throttle air bottle gizmo, it let the pedal go to floor then delay box on release activated the air plunger to snap the throttle on. I liked that system better because the squirters were not used up.

I have often wondered myself and this is about as close as I can get to a reason.

I built a system like you describe, did not use a rectifier, or a delay box. Just locked front and back brakes, my Dodge had drums on all wheels then. Stage the car, hit the button lock the wheels, air cylinder expanded and held at launch RPM, released the button, line locks released, air cylinder closed and launched the car. You could dial it into the tree by changing the air pressure coming out of the bottle with a regulator. Worked very well.

Thank you

Some classes prohibit rear wheel Line Locs - Stock & Super Stock for 2. General regs says - application and release must be a direct action by the driver. No electronics, hydraulics, pneumatics, or other device may affect brake operation. Line-loc can be used to hold the car on the line, but It has to be applied and released with a driver operated switch. Can't be tied into a clutch switch, delay box, etc.

I should of said I separated them just to do a burn out, one button for front (on shifter) the other for both on steering wheel leaving on top light, then adjusted in the box for reaction times. I also had my practice box tied into it all so I could sit in staging lane popping the button about 20 times to get in a groove.