I'm building a V8 car LS1/G-50/996
and not having anti-lock brakes I am looking for the best balance I can get. My first V8 car tended to lock up the front tires and that's just not good. With so much weight in the rear/middle and little up front I was thinking about installing 2 Adjustable Proportioning Valves. Obviously one for the front adjustment and one at the rear. I really being honest here, I need some input.
Thoughts ?

Check out the wilwood site.

http://www.wilwood.com/MasterCylinders/Mas...nderValves.aspx

There are many different types of "proportioning valves" with varying levels of sophistication.

Two valves just doesn't make sense. You only need one, to limit the pressure going to the rear.

Note that you do want the front to lock before the rear does, because if the rear locks up first it will want to pass the front. But for maximum slowing, you want the fronts to lock just before the rears do.

--DD

I have "S" calipers in the front and 914 6 calipers on the back and I threw away my proportioning valve a long time ago. My anti-lock system is in the muscles of my right leg. It's best if your brakes don't lock up at all but if they do, its much better and safer if the fronts lock up first.

On my 914/LS1 with '89 Carrera brakes, front and rear, I used the Wilwood proportioning valve (for the rear circuit only) like the one in the link above.

Andys

I'd be more worried about SS braided Teflon brake hose failure myself ...............

The Cap'n

I installed the Wilwood valve on a 1953 Chevy PU I built. I had the rears locking up prior to the fronts. I placed it inline to the rear brakes and the problem was solved with a few simple turns.

Though it's somewhat controversial, I also removed the pro portioning valve on my car and replaced it with a simple T fitting. With Carrera calipers on the front! and the stock 914 rear calipers, I stop well and haven't experienced rear lockup under hard braking. Any rear proportioning valve should work if you install it properly.

JWID ( just what I did)

The Cap'n

I'm missing something here ( no jokes please ) ? My little brain thought
Teflon SS lines were the way to go ?

When teflon lines fail, they fail catastrophically. Meaning you got no brakes like right now! Stock rubber lines have a more graceful degradation.

"The way to go"? I'm guessing you aren't aware of my rather strong bias against them. They require frequent careful inspection, and there are well informed experts that recommend replacement every 2 years. The failure mode of the OE style runner hoses is a gradual softening of the pedal feel, or internal swelling that prevents the fluid (and therefore the pistons) from retracting. This happens in a reasonably maintained system after maybe 20-25 years. The failure mode of the SS braided Teflon flex lines is generally absolute and total loss of fluid and braking function. I've seen it personally, and I've heard horror stories from a number of other techs, racers, and enthusiasts. One guy on the Audi 20v Quattro forum had his fail during a track event. He was VERY fortunate there was a substantial gravel run-off area right next to the track when it happened. A little research will show you that even the DOT approved lines carry NO warranty, the excuse being they're race parts ........... Think about this: Well under 5% of my customers over the last 25 years had SS brake hoses installed on their cars, but well over 95 % of the flexible brake line failures I repaired were from that group.

That's it for now, I gotta go try to get a life!

The Cap'n

I can see from the picture that the first stainless hose installation mistake made is the hose has a twist. Stainless steel hose doesn’t have a printed lay line like other hoses.

A lay line is all the printing and stripes on hoses so that you can spot any twists when you install them.

I got myself a set of factory lines, funny building a 500 HP, 2400 lb. car a bit of a oxymoron.