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Line lock- on rear brakes?

daytona kid

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A bud told me he was putting his line-lock on his rear brakes. I said that's not going to work but he explained that it actually works better. You hit the switch without brakes applied and then you will only have front brakes which you can pedal on an off if/as needed during burn-out. Finish burnout, switch back off and rear brakes now working. Makes since to me, I will be trying this out soon and will report my test results. Anyone else tried this? Anyone see any reason not to do it this way?
 
The reason for locking the front brakes is so you don't have to hold the brake pedal.
 
So tell us what line lock you are going to use.
 
That makes sense. I’ve wanted to pedal a bit heating the tires.
 
Add an annoying indicator light so you do not forget it on
 
A bud told me he was putting his line-lock on his rear brakes. I said that's not going to work but he explained that it actually works better. You hit the switch without brakes applied and then you will only have front brakes which you can pedal on an off if/as needed during burn-out. Finish burnout, switch back off and rear brakes now working. Makes since to me, I will be trying this out soon and will report my test results. Anyone else tried this? Anyone see any reason not to do it this way?

If he installs it that way then he will also have his foot on the brake at the starting line. This is fine for an automatic car but if you have three pedals then you want the line loc in the front brake line so you can have your foot on the clutch.
 
A line lock is designed to lock in pressure on either the front or rear line. For what the poster is claiming to do is he would have to lock out pressure form the rear system.
 
Actually it does make sense, when used as a roll control.... It will help with launch if you use it right. But you still need a roll control for the front, and a switch so you can use front only, or both, at the proper time. The method you describe tho, i dunno....
 
I don't believe doing a line loc like this is actually for real drag racing. Sounds more like it is for doing "show off" burnouts.
 
You would have to route the lines reversed into the unit. Swapping the inlet for the outlet. It's not designed to be in the rear system. If it stuck you would have no rear brakes. Yes, I've seen them stick. Bad idea. Fluid flows thru the line lock ports in either direction when it's not activated. when it's activated it blocks the fluid flow from the outlet towards the inlet. When mounted in the front line this causes the front brakes to stay applied. If the line lock is in the rear sytem and its sticks the brakes will not apply due to the fact it's plumbed with the flow path reversed. No need to install it in the rear. The front brake location works just fine.
Doug
 
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Gee, maybe I was doing it all wrong for all those years and thousands of runs?? Don't think so.
 
My line lock is installed in the rear brake line. It was installed that way when I purchased the car. Works excellent, no plans to change it.
 
Pumbing to the rear line is how the "Road Kill" crowd do their " Burn outs for distance" by locking out the rear brakes from being applied and lightly holding brake pressure with the brake pedal on the front brakes allowing the car to move foward at a controlled speed.
 
It works great. It’s the way mine has been plumbed for over a decade. before you laugh, explain to me why you WOULDN'T want control over the front brakes while doing your burnout.
Since a line lock is actually a one-way valve, You simply have to plumb it backwards in the line to make it work properly.
 
I've never had mine stick. But seen it enough times to know it happens. I don't know about you guys. But I'd hate to make 150 mph pass and find out I had no rear brakes at the stripe. Lots of stuff that works. But until you've been in that Oh S - - t moment it goes on thought about. I've had those. And fortunately they've turned out OK. Afterwards I thought about what could be changed if it happened again. Sometimes it's out of your control. Like running through 7 qts of the previous guys trans fluid at the stripe at 148. T his year I broke a trans cooler. It dumped most all the fluid. But when building the car my thought was keep the trans fluid way from the tires. The cooler sets under the drivers seat inside the subframe connectors. Not a drop went outside the connectors. Years ago I left with my hand on the line lock button. One front tire was roling, the other was not. Had no idea at the time why the car was pulling to the left. Decided to lift and moved my right hand (which had been resting on the button) to the steering wheel. It made a left NOW! at 117. Nearly put it on the right side tires only. The button now has a fail safe and can only activate once w/o being reset. Be safe guys. Just cause it works doesn't mean it can't be improved.
Doug
 
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I’m fine with mine in the rear, I can tell on the brake pedal when my line lock is on or off, pedal is rock solid and at the top with the lock on. My pedal drops an inch as soon as I release the switch after the burnout, I feel it in the pedal as the red LED light on the dash goes out. If it wasn’t allowed due to safety yeah I’d change it.
 
Technically , they're not allowed to be on the rear in competition. But if tech never looks, and you have no enemies, you are free to do as you wish.
The reason for the rule is, if the rear locks up for any reason, you're toast.
Screenshot_20230112_095415_Chrome.jpg
 
Why do you need control of the front brakes during a burnout? Set the line lock. Hit the throttle. When it's spinning release the button. As it rolls out of the water lift off the throttle (your converter will thank you). My burnouts are recorded on the playback tach. Usually 3.4-3.6 seconds.
Doug
 
I have seen a car leave with the front wheels up and when it lands the front wheels were still locked. I've seen this a couple of times in the past. Driver error or mechanical failure?
 
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