When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've recently upgraded to big reds with cayenne 330mm rotors on the front of my 86 951, and left the stock brakes in the rear.
I run relatively hard suspension, and 255 semi slicks all round. At the moment I still have the stock 5/18 proportioning valve, and I'm trying to decide which one I should get to provide some more rear braking happening.
5/33
5/45
or an adjustable unit.
Ideally I'd like to get an adjustable unit, but I'd prefer the simpler install of the factory replacements.
Those fixed proportioning valves are fine for street/occational DE cars but when I raced I found that an adjustable valve was invaluable. One of the advantages is that you can adjust bias on the fly for changing conditions, such as a wet track, which you cannot do with a fixed bias. This isn’t my car but it’s how mine was plumbed in, it was simply taped into the rear line and extended though the floor.
Those fixed proportioning valves are fine for street/occational DE cars but when I raced I found that an adjustable valve was invaluable. One of the advantages is that you can adjust bias on the fly for changing conditions, such as a wet track, which you cannot do with a fixed bias. This isn’t my car but it’s how mine was plumbed in, it was simply taped into the rear line and extended though the floor.
Cool, the more I think about, the more I think this is what I should do. I reckon I'll get some brake line tubing and a flare tool and see what I can do.
Do you have to open the valve all the way every time you bleed the brakes?
...Do you have to open the valve all the way every time you bleed the brakes?
You know, I can’t remember and looking back at the instructions it doesn’t say. Maybe someone else can confirm the bleeding as I’ve moved to a different set-up (right). It’s a shame you are not stateside as I’d send you my old Wilwood valve for the cost of shipping.
I run 993TT front brakes and stock rears on my 951, and after some testing I found that the 5/33 valve works best for my car (@2750 lbs, with driver). The stock valve 5/18 was too front biased and the 5/45 was too rear.
12-14-2017, 02:40 AM
Which brake proportioning valve for big red?
