How do you install an adjustable proportioning valve?

[PorscheGuy79]

I am going to install an adjustable proportioning valve in my SC with Carrera brakes and I was curious about how you guys plumb it in. I would like it to be near the drivers seat so I can set it up on the fly. Any tips?

[gestalt1]

i'm planning on running flexable an-3 teflon/stainless clad brake hose for the complete brake system in my car - no hard lines. i have not done this yet but i got the idea from rally cars where tis is more typical. i would put the valve in-line with the ling going to the rear brakes. to add a prop. valve into the stock system you would need to pull out the hard line in the tunnel and cut/flare the ends to add the valve.

[PorscheGuy79]

Here is my 5min rough paint sketch of this idea...

(please note im not exactly sure how the brake like runs though the tunnel, do 2 lines run through the tunnel or just one?)

[gestalt1]

in my 73 it was only 1 line with a "T" fitting going to each rear wheel.

[gestalt1]

also, there is the battery cable, wiring harness, throttle cable, tach drive, shifter rod and 2 fuel lines that look like brake lines in there - its a little tight. i think you would need to cut a decent sized hole to get to the brake line and cut it, flare the ends etc.. it might be better to dissconnect the rear lines, pull out the line from where it enters the tunnel and re-route the line outside the tunnel.

[PorscheGuy79]

So, I have thought for a while about how to install this bad boy and I have come down with this idea. Since the tunnel might not be the easiest way to do things I think I may use the hardlines that are in the front trunk.

My idea is to cut into the rear brake line where the stock Carrera p/v would go but instead intall in line some flexable hose and run that through the wall to the adjustable p/v within reach of the driver. Then run another flex hose back to the same spot where I cut the line before and have it continue on its way. Does this sound like a good idea?

[Vipergrün]

Couldn't you do it in-line right at the MC??

[PorscheGuy79]

Originally posted by bb80sc
Couldn't you do it in-line right at the MC??

What would be the benefits to doing it like you suggest? Wouldnt it be more work to remove all the blower motors and such?

[Craig 930 RS]

How about this?

[Craig 930 RS]

[Bill Verburg]

I would put it where you have the arrow in the above pic. The factory did mount them where the driver could adjust them under way but that's not usually necessary. Craig's suggestion makes it more convenient.

[Craig 930 RS]

Yep. Since it is essentially a 'set and leave it ' proposition, mounting in the trunk works just fine.

[PorscheGuy79]

Originally posted by gestalt1
i'm planning on running flexable an-3 teflon/stainless clad brake hose for the complete brake system in my car - no hard lines. i have not done this yet but i got the idea from rally cars where tis is more typical. i would put the valve in-line with the ling going to the rear brakes. to add a prop. valve into the stock system you would need to pull out the hard line in the tunnel and cut/flare the ends to add the valve.

where do you buy that stuff?

[gestalt1]

summit racing, hrp, pegasus, many other race catalogs. the hard part is figuring out all the different fittings/adaptors needed.

[efhughes3]

Maybe a dumb question, but why do you need this with Carrera brakes? I'd think their stopping power is mild enough with an SC to not bother. With my 993 brakes that I put on my Carrera, simply removing the PV worked well for me.

[PorscheGuy79]

Stock Carrera brakes have less pressure on the rears due to a factory P/v, an SC doesnt have a P/v. So when I uprated my brakes to Carrera brakes the bias isnt right for the car since the rears are too big.

[Jeff Alton]

Craig, is yours plumbed into the line to the fronts? Hard to tell from the pic. What is the brake set up on that car?

Cheers

[Craig 930 RS]

1842 big reds up front, 1203 944T rear

[PorscheGuy79]

Okay guys, I am having some trouble with this project. I few questions.

Can I bend the tubes in the line in the trunk up a bit to attach and thread on the flairings?

What size hose ends would be needed for that size of line?

Does it matter what flix line size I use, as long as the end is 1/8ths to fit the P/v and is rated for this type of use?




So basically, for your review guys, I need the following...

Flairing kit
Flex brake line hose
Fittings from the old lines to the flex hose
Fittings from the flex hose to and from the P/v
P/v

[Craig 930 RS]

Man, I wish I knew more to help ya'll......but I didn't install it and it is really hard to see where the lines actually go.....