Line lock

[Archi]

Hi all,

What is a line lock? Does it differ from a brake proportioning valve and are they street legal?
The only thing I want to do with my brakes is upgrade the compound although I heard about line locks today and was wondering what they are exactly...

I'm guessing a drag set-up like this would have something similar?

[beavis]

Line Lock is generally only for burnouts or drag applications.
It's a means of locking the front wheels, allowing you to do a burnout.

If you're driving a reasonably standard car, and only on the street, you definitely dont need a line lock, and likely don't need a proportioning valve either.

I use Hawk HP+ as a good strong street/spirited driver pad. Probably a bit too much for the everyday commuter car however.

[hks_kansei]

As above, it's basically just a way to have only the front brakes engage.

Some people use a bias adjuster as a cheap alternative, but normally a proper line lock will be a cabin operated switch/handle. Kind of like a handbrake for the front wheels.

Usage wise, they pretty much exist purely for burnouts (ie: drag racing)
For road use, or circuit racing they really dont have any use, since all they're doing is disabling the rear brakes totally, meaning the car wont stop well. (plus on an MX5 normally you'd use a bias adjuster to give the rears a bit more bias)


Regarding street legal, probably not, but in saying that, bias adjusters arent legal either.
TO be honest, very little brake changes are legal without paying extra to go through some kind of testing/certification.