Line Lock on Rear Drums

[V6UnderPressure]

Planning on using a line lock on the rear drums to hold boost before launching. Any tips or precautions I need to take? I recently purchased those new shoes that supposedly hold 4-5psi more boost. How much can I hold on the street? I will be running mickey thompson sportsman pros 26x10.5's. And what is the max that you think these drums CAN hold no matter what. Thanks!

Scott

 

[azgn]

not so sure you can hold any more boost with a line lock than just mashing the pedal and holding it....with good brakes (front & rear) you should be able to hold 10 lbs at least

think a line lock would just get in the way of things on the rear brakes....put it on the front brakes where it belongs and keep your rear brakes nice and cool after a burnout.......

 

[V6UnderPressure]

I already have one for the front. so I figured if I had 100% of the pressure to the rear it could hold more easily on the drop and I wont risk breaking calipers, pads etc. No???

Scott

 

[azgn]

so you were planning on using the rear brakes only? Not a good idea since if ya don't spin 'em, you'll just push through

if you want to maximize your launch, get a trans brake

I still say you cannot generate any more brake pressure with a line lock than without.....just set your brakes up to work properly
(I normally use a trans brake, but I can hold 10-15 using the foot brake...a lot of that has to do with matching the converter and turbo also)

 

[TurboDave]

Dont do it Scott. Keep the line lock on the fronts where it belongs. You wont gain an ounce by putting line lock on the rears.

Keeping the line lock on the fronts will keep the rears cool during burnouts. When they're cool, they'll hold all they can on the foot brake.

If they get, even a little warm, you loose efficiency big time on them (rears).

 

[tom h]

I've occasionally wondered whether a line lock on all 4 wheels would make for a faster, or more precise, brake release on the last yellow light ... a "poor mans" transbrake without the perceived hassle and breakage risk of a transbrake.

it would seem releasing your finger off a microswitch is faster than lifting your leg off the brake pedal ...

 

[Joe 1320]

What he is trying to do is use the front line lock for the burnout and engage the rear for launch. In theory, this takes any slack out of the driveline and is a little more forgiving on the driveline parts. You won't be able to build any more boost than what would be done by the footbrake. If you were able to lock BOTH the fronts and rears and get them to release at the same time at launch, that would be the ticket. The fronts would provide extra roll control should you start to overpower the rears.

 

[DCVING 6]

Originally posted by Scott4DMny
I recently purchased those new shoes that supposedly hold 4-5psi more boost.

Hey Scott, can you give me some details on these brakes? I need to do mine this winter.

 

[tim87tr]

Re: Re: Line Lock on Rear Drums

Originally posted by DCVING 6
Hey Scott, can you give me some details on these brakes? I need to do mine this winter.

I bought my upgraded wheel cylinders, soft rear shoes, and line lock (Morosso) from Jack Cotton. See the website. Instructions for install are on the tech section of gnttype.org. The car will hold 10 lb of boost, although my stock suspension can not handle that type of launch without rebounding and unloading. I need to figure something out there.

One other thing is the new pads take about 20 or 30 miles to break in before they will hold that boost. I did not have my drums turned. Also even with the rear shoe adjusters all the way in, the drum is a tight fit. I used a rubber mallet to tap.

 

[J Banning]

If you're having problems holding boost on the line and don't want to go with a trans brake, do a search on Jumper Valve.

Although a little time consuming to put in, I'm VERY happy with the opperation of mine. It'll hold 15psi+ where the brakes would only hold approx. 5psi alone.

-Banning.

 

[V6UnderPressure]

Where did you get this jumper valve??? And secondly, look at the previous post on the tires I will be using. what is the highest psi you think I can launch at without breaking them loose. This is for the street encounters.


Scott

 

[J Banning]

Wait a second... your sig says you have a StageRight. Why not just use that?

Don't see anything about your tires. What are they? With a trans brake & PT54 turbo they better be something meaty (no drag radials).

-Banning.

 

[V6UnderPressure]

My Trans brake is removed, never used it. My sig is outdated. sorry about that. I am running mickey thompson sportsman pros 26x10.5 on the rear. If I were to just run regular brakes for the launch, what is the most psi it will hold?

Scott

 

[gnturbo]

so a traditional line lock works like this-mash the brake-push and hold the button-do your burn out and let off the button to unlock the front brakes.what about this put the line lock on the rear line to block juice going to the rear-push the button to activate the solinoid blocking fluid to the rear and then you can use your foot brake to hold the front and modulate out of your burn out with your foot instead of the button.Any difference or is this just personal preference?I am about to put a line lock on my car but am undecided which method .I ahev tried both and I like the line lock to block the rear juice better,just wanted to know of any drawbacks I am not thinking of.Thanks

 

[azgn]

well, with a traditional line lock, you mash the brake, push and hold the button and then release the brake pedal.....this will hold brake pressure on the fronts and no brake pressure on the rears....do your burnout and release the button

 

[gnturbo]

did I miss something?

 

[wiked87gn]

Proportioning valve for the rear.

what you need to do is use an adjustable proportioning valve for the rear brakes, it allows you to move more pressure to the rear brakes when you want to hold more boost, the only downside is that in a panic stop you can lock up your rear brakes and it will come around on you, you just have to know the settings on it that's all..

 

[J Banning]

The components for a jumper valve can be purchased from a place like Grainger (www.grainger.com). The main parts you'd need are: the solenoid, distribution block for the solenoid to attach to, and t-fittings (preferably double flared).

For more info you can also do a search on this site for "jumper valve" and my name "J Banning"

Hope this helps.
-Banning.

 

[azgn]

didn't see where you released the brake pedal...........when the line lock was on.....

 

[gnturbo]

with having the line lock on the rears and holding the button before you press the brake you would actually keep pressure from going to the rear while you held the brake and did your burn out then you could ease up to the second stage light push brakes lock rear build all the boost you want then push the button to release the rear brakes at the third amber light and let her fly,interesting concept huh,almost sounds crazy enough to work.....