GaryK

Anyone tried a different brake proportioning valve on their car? I understand the common upgrade is to the 928 valve, which channels more pressure to the rear brakes. What impact will this have on the rears tendency to lock up and the ABS?

My car is a '89 and, though I haven't pulled the fender liner to check the p/n yet, I found this on the 944 FAQ (posted to <a href="http://www.connact.com/~kgross/FAQ/944faq13.html" target="_blank">http://www.connact.com/~kgross/FAQ/944faq13.html</a> and many other places):

"With the 944S, Porsche introduced a 33/5 proportioning valve. For the 944 Turbo and 944S2, Porsche originally used an 18/5 proportioning valve, then later superseded it to the same 33/5 valve used on the 944S and some 928-series models."

So should a Turbo S have the 33/5 valve?

mumzer

i have used the 964 turbo piece to great effect.

5/55 slope i believe

ninefiveone

I use the 33 valve. I don't have ABS and do notice that it's easier to lock up the rears but only under extreme situations. Overall it's an effective improvement in braking. If you ever had to get on the brakes hard in a wet corner, the rear would likely step out on you. Know what you're doing.

GrantG

Gary - I installed the valve that Paragon Products sells. I haven't had any lock-up problems (or ABS pumping) and the fronts seem to run a tad cooler. We'll see tomorrow at the track how it's working.

Looking forward to meeting you - hope it doesn't rain too much...

-Grant

Robby

I did it (5/33) for my Turbo S- I really liked it at first- I think I'm just used to it now though- it didn't help shorten distances though like it should have (a foot or two at least) but I think MY prob is shi**y brake pads... As for 5/44 and 5/55 valves- I wouldn't recommend this w/out ABS or at LEAST, a larger caliper (than stock) up front- maybe BR's- I could feel the rears wanting to lock (ABS pulsing and rear twitching for just an INSTANT) when I first got mine on, but haven't niticed it much lately- the 5/55 would DEFINATELY do it though, but w/ABS, MAY be controllable- I wouldn't try it though- w/BR's I MIGHT go w/a 5/44... The stock BTW is 5/18...

GaryK

Thanks for the feedback; I've ordered the 33/5 valve from the 928S4. Btw, my favorite source - Paragon Products - was out of the stock, so I went to the dealer.
I've had good luck and decent prices ordering Porsche (and Audi) parts from Carlsen Motors Cars in Palo Alto, CA -- ask for Mike in Porsche parts. In my experience, it's easier to deal with a knowledgeable parts guy at a dealership 1500mi away than with the morons at the local dealers' parts counters.