how does linelock work?

[cougarracing]

can someone explain to me the use of linelock and how you lauch the vehicle off the line. i know what it is and that it brakes the front wheels and on an automatic gearbox vehicle i assume you just press the linelock button, bring up the revs and then release the button when the light goes green....what is the process on a manual gearbox vehicle? how do you use the clutch on the startline etc? any help is appreciated, its something ive never understood!

[NitroWars]

Both can work with a solenoid although I am not certain that a solenoid operated linelock is legal. Holding the button in on a transbrake can create disadvantages - if your opponent is aware that you have a linelock he could play staging games so that either your thumb goes "dead" or the button gets very hot resulting in an early release. One reason for the time out feature on trees...

[Time Machine]

NitroWars said:

Holding the button in on a transbrake can create disadvantages - if your opponent is aware that you have a linelock he could play staging games so that either your thumb goes "dead" or the button gets very hot resulting in an early release.

That and it'll boil/burn the trans fluid unless you have a good cooler fitted.

[leecb05]

I used to have line locks on my street cars basically i only used it to do burn outs with but it is a device that holds your front brakes on while allowing the rear brakes to be released. the basics are that when you press your foot brake after going through the bleach box you then press down your brake pedal, then you press the line lock button and relese the foot brake and that activetes a valve thet will stop the brake fluid returning back to the master cylinder and keeps the front wheels locked while you do your burn out. to release it you either press the button again or press the foot brake which ever system you have, but i would never use it as a system to launch from the line thats what god gave us clutches for

[herb andrews]

cougarracing said:

what is the process on a manual gearbox vehicle? how do you use the clutch on the startline etc?

Even with the correct .120” air gap in the clutch, a problem we used to have with a Lenco/Liberty and a slider clutch, in an altered, was once in stage and the R’s (9000+) were up, the car would creep forward and red light.
There was no way we could get good launches, decent reaction times and consistent 60’ times.
Some of this was down to driver concentration, as there’s a lot going on in a short amount of time and balancing staging on the clutch, holding the brakes and manually pressing the throttle to try and keep a steady rpm is a tough act.

The way we fixed it was to use a line lock on the rear brakes, wired to a micro switch mounted on the clutch pedal. Once the car was staged, the brakes were applied and a switch on the steering wheel pressed. This applied power to the micro switch, which in turn powered the line lock, which stopped the car moving forward. At the same time the throttle was fully depressed, the launch chip in the MSD ignition holding the rpm to a pre determined figure (typically 6000).
When the clutch was released the micro switch turned off the power to the line lock, whilst the MSD went to the ‘high side’ 9500 rpm chip, and the car launched.

Reaction times improved, because there was less to think about, along with consistent and improved 60’ times, due to good launches.

It worked for us. Hope that helps

Herb

Edited by herb andrews on Sunday 3rd February 23:35

[anonymous-user]

We use a line-lock to stage too. As Herb mentions, even with the correct air gap in the clutch, when the RPM is raised the centrifugal levers apply more pressure and the car will creep through the lights. When Dad lights up the pre-stage bulbs he builds up around 500psi (on the brake pressure gauge) and places his thumb on the line-lock button which is located on top of the shifter tower, before releasing the brake pedal again. By letting the clutch out very slowly and upping the RPM to around 2000 the car drives “through” the front brakes very slowly but as soon as the clutch is pressed again the car stops dead. Using this method he “bumps” the car in to stage before flooring the clutch and throttle and waiting for the tree. When he launches he naturally releases the line-lock as he gets ready to punch 2nd gear.