Anyone ever had an aftermarket one apart?? Are they simple barrel balves, or do they have sprung ball valves or similar for pressure regulation???

 

The reason I ask is, I can get hold of a range of hydraulic valves but need to know how complex the ones in Demon Tweeks etc are!!

 

Rich

Just found this on here http://dsr.racer.net/brake_bias.htm

 

Brake Proportioning Valve

 

Brake proportioning valves on tandem master cylinder systems act much like a balancing bar on dual master cylinder systems. The proportioning valve is usually used in the rear brake line. It can reduce the pressure by 0 to 50% (typically). Proportioning valves only reduce the pressure in one system unlike balance bars that take from one side and give to the other

 

HTH

 

CheerZ,

 

Andy

Just found this on here http://dsr.racer.net/brake_bias.htm

 

 

 

HTH

 

CheerZ,

 

Andy

 

Thanks for looking... seein as it's my mate's track car, reckon we'll just have a go!! Can't see that it's too complicated!

 

Rich

Just found this on here http://dsr.racer.net/brake_bias.htm

 

 

 

HTH

 

CheerZ,

 

Andy

 

Andy correct me if i'm wrong. After installing my 6pot endless brake kit i was thinking of installing the 4pot stock system on the back of my car put couldnt do it cause i wasnt able to contrrol the pressure on the back system. Now with the bias i would be able to do this right?

 

Pambos

Yeah this should be fine :) Since the valve is reducing the rear braking force then I don't see why you couldn't fit a larger setup on the back. I think if you are doing that though, its probably an idea to remove the ABS system as this won't be able to cope properly with the bigger setup. Even with just R33/34 brakes on it doesn't work particularly well - oh well, less weight! :D

Yeah this should be fine :) Since the valve is reducing the rear braking force then I don't see why you couldn't fit a larger setup on the back. I think if you are doing that though, its probably an idea to remove the ABS system as this won't be able to cope properly with the bigger setup. Even with just R33/34 brakes on it doesn't work particularly well - oh well, less weight! :D

 

Yes that's right my brakes lock up very very easily but they are impressive

I've seriously considered removing the ABS on my car - it doesn't exactly work very well anyway now with the larger front calipers. Presumably something to do the increased volume of the fluid chambers...

I've seriously considered removing the ABS on my car - it doesn't exactly work very well anyway now with the larger front calipers. Presumably something to do the increased volume of the fluid chambers...

 

JUN director told me that with bigger calipers and wheels the abs sensors dont work properly their advise was to remove it but they told me it's a lot of trouble to do that

Sounds like a plan then ;) I'll do some looking into it :)

Sounds like a plan then ;) I'll do some looking into it :)

 

 

Could i suggest a nice faq???

 

Andy if u stuck on something and need any help on doing this let me know and'll ask someone in JUN to guideline us

Yeah I'll see what I can do :) No engine in mine at the moment so ideal time to check out the routes of the pipework etc.

 

Cheers for the offer of help too :)

 

Had a quick look around on the net but can't find anything Z32 related so looks like starting from scratch....

Yeah I'll see what I can do :) No engine in mine at the moment so ideal time to check out the routes of the pipework etc.

 

Cheers for the offer of help too :)

 

Had a quick look around on the net but can't find anything Z32 related so looks like starting from scratch....

 

If it wasnt for helping each other forums like this wouldnt exist.

It's not too hard to remove.

Just put a tee on the outlet on the matster cyl then feed one line to each front caliper.

Use one of the original lines back to the ABS and tee that to the 2 rear brakes. Remove the other line, the job done.

Not that I'm planning to do this soon or anything ...

It's not too hard to remove.

Just put a tee on the outlet on the matster cyl then feed one line to each front caliper.

Use one of the original lines back to the ABS and tee that to the 2 rear brakes. Remove the other line, the job done.

Not that I'm planning to do this soon or anything ...

 

I think the difficult part has to do something with the lectrical stuff like removing the abs computer and the hard lines inside the car

Just unplug it the computer, actuator and pull the bulb out of the dash.

May be worth looking into the circuit to short the healthy signal from the ABS ECU so that low fluid would still activate the light. I'll look into it when I do mine.

If you put the T's in consider running one pipe from each port on the master cylinder to a front brake and the other to the opposite rear brake (i.e. front left and rear right on the same circuit). This is a legal requirement for passenger cars in Europe and a safety thing. If a circuit goes down because of a leak then you always have brake force at both ends of the car and both sides. The legal aspect applies to new car designs, not sure about modifications, don't know what the MOT bloke would make of it (if he notices ;) )

 

The ABS can't cope with different callipers because it is not a purely reactive system, the software has a certain amount of 'knowledge' in that it knows the relationship between line pressure and brake force so it knows how to modulate. A larger calliper will alter this relationship and cause the ABS to control the wheel poorly (although a well tuned system will always find the limit of tyre / road adhesion it is what it does after this point that is affected by a calliper swap).

Dont think Mr. Insurance will be too happy if you huy's remove your ABS and have an accident without telling them though. :nono: He will no doubt levy your insurance massively the *******.

 

Ivan

You can't do a diagonal split if you want a bias valve though. Unless you can get a dual one, but never seen one before.

Or you use two.

Yeah, could get some really bizarre brake setups then!!

"What does this knob do?" crash, burn. :x:

 

You might find that some vans without ABS use a twin valve which adjusts from the rear suspension height. Adapting one of these might be a posibility, then both circuits will adjust at once.