fst951

Hi Guys.

I used to have the part numbers for the different pressure regulators for the rear braking circuit of the brake system.

I have a 1985 Euro 928 with ABS and need to get a different bias valve.

Any help appreicated. I just can't find it in PET. I think that the last time I saw it was in the 951 section of PET. I just can't track it down.

Thanks to all in advance.

Mark

Call any of the Big 3 - I am sure they can take care of this!

fst951

I would have though so as well.

Any help appreciated.

Thanks.

Jim bailey - 928 International

The 33 Bar is 928 355 305 02, 18 Bar is 951 355 305 01 , 55 Bar is 964 355 305 10 ..... we sometimes get busy helping customers with their orders.

T_MaX

What would give the car more pressure to the rear brakes?

Is it the greater the bar, more pressure is applied or visa versa?

18 bar - 951 355 305 01
33 bar - 928 355 305 02
55 bar - 964 355 305 10

fst951

Thanks Jim.

That was helpful.

slate blue

Hi Jim how much are your 55 bar bias valves? Here new, they go for $100, my wrecker can't find one as yet. I'm experimenting at the moment, with a 33 bar I lock the fronts too easy, with none I lock the rears, so it is guess work and don't wont at the moment to throw too much money at it as I may have to buy an adjustable one to solve the problem.

Jim M.

I have the 55 Bar valve in my GTS and love it. Before I installed it, I could get the front anti-lock to engage with high G stops that weren't panic stops. With the 55 Bar unit I have never engaged the anti-lock with the same type high G stops. The GTS has the big black (in my case Red) front calipers and bigger rotors. If you have the S4 calipers (don't know what the Euro 85 has) you may want to stay with the 33 Bar for awhile or get info from someone who's BTDT.

Jim Mayzurk
93 GTS

Mark

Jim M - I have upgraded my '85 EURO to the "Big Black's"...do you think the 55 bar will work that well for me, too?

slate blue

QUOTE] have the 55 Bar valve in my GTS and love it. Before I installed it, I could get the front anti-lock to engage with high G stops that weren't panic stops. With the 55 Bar unit I have never engaged the anti-lock with the same type high G stops. The GTS has the big black (in my case Red) front calipers and bigger rotors. If you have the S4 calipers (don't know what the Euro 85 has) you may want to stay with the 33 Bar for awhile or get info from someone who's BTDT.

My car has 993 twin turbo brakes, as such my rear pistons are bigger and need to have more pressure supplied than s4. As I mentioned I have a 33 bar and that is with a master cylinder change to 23 mm all the way through it still locks the fronts too easily. So I want to try a 55 bar.

Jim bailey - 928 International

New 55 Bar for $66. no used.

slate blue

Sounds very fair Jim, I'm going to my local wrecker today, if no luck I will call tommorow morning.

Cheers Greg

Jim bailey - 928 International

It is worth noting that the adjustable brake bias valves do not function the same as Porsche valves. The Porsche valve initially gives the same pressure front and rear then at the preset 33 or 55 bar at that point reduces the incremental pressure to the rear brakes. The racing adjustable decreases the pressure to the rear ALL the time but in racing braking tends to be hard and harder. Porsche and nearly all manufacturers want the front brakes to lock up well before the rears. Far better that you plow off the road rather than spin off the road from a stand point of manufacturers liability. The adjustable racing valve does allow you to trim the bias based on fuel weight changes and tire changes.

slate blue

Thanks Jim for that info, I fortunatly was aware of that, but decided to go the factory route for street legality and ease of fitment, was a lot cheaper too, I managed to get one today. I dont know what it was off but I screwed it out of an ABS control unit. The brakes are great now, mash them hard no lock up, you really need to give them a good shove to lock. The fronts now go first, so perfect as far as I'm concerned.

We did some very crude timing and got 3 seconds 100 to 0 KPH. As I said very crude, with a stop watch. Seat of the pants feel is good, driver control is excellent so I'm