Juergen

Hi,
i´ve installed in front a PORSCHE brake system and at rear the stock one.
I´ve the problem that the meassured brakepower at the rear brakes is to low. Does anybody knows if there is a brake force regulator for the rear brakes which is dependent from the weight in the car trunk? Where is it placed?

Or is there another way to can regulate the rear brake pressure?

Thank you guys!

BR Juergen

87 vette 81 big girl

Install an adjustable proportioning valve.

Like from Wilwood Brakes.

Or similar.

Keep a small journal of actual measured stopping distances from 70mph to 0 mph.

BR

Churchkey

If you have retained the stock master cylinder DRM has a prop valve spring for the master cyl that will increase the hydraulic pressure to the rear calipers.

I run a Wilwood adjustable prop valve for the rear however it only adjusts to lessen hydraulic pressure not increase it.

Additional info would be helpful.

What year vehicle?
ABS still operational?
Did you just change front calipers or?
Stock master cylinder? If not stock what is the master cylinder bore size?
Soft (stock) rear brake pads will provide better initial bite.

c4cruiser

The DRM springs are designed for C4's (separate versions for ABS and non-ABS) and 1997-2000 C5's. Whether or not their spring would work for Porsche front calipers may be something that DRM would have to answer.

DRM offers both a Wildwood 6-piston caliper front brake upgrade for C4's and C5's but there is nothing mentioned about a proportioning spring or a replacement master cylinder.

The OP can contact DRM here on their "Contact us" page.

l98tpi

OMG, Sorry I cannot help myself. Why don't you install a Volkswagen transmission and a BMW rear axle?"

On a serious note, if your rear brakes do work and you just want more brake bias at the rear, just install some more agressive brake pad in the rear.

Juergen

it´s a 1992 LT1.

yes, i´ve already installed the stock master clinder. i never touched it or changed anything on it (except the brake fluid ;-D)
In front is a whole set from Porsche (brembo) calipers, rotors and pads.
At rear i´ve complete stock brakes. Also the pads are the stock one from 1992. (i´ve only 23000 miles on the car, till this day it was not necessary to change it).

If i move stronger the brake pad i get an error from ASR and ABS
on the control center and the bulbs light up constant. But i cleaned the ABS sensors at back side and i´ll hope it would be ok now. But i still didnt tested it.

BR Juergen

Black89Z51

As Churchkey stated, install the DRM brake proportioning spring. That will help add more pressure to the rear brakes. It's only $12.95, so it shouldn't break the bank.

http://dougrippie.com/?p=404

Select from the dropdown menu below the description to pick ABS or non-ABS.

jaa1992

When I rebuilt my brakes last year I put the DRM spring in. Even with the stock j55 setup it helps a lot. I run carbotech xp12 pads on the front and xp10 pads in the rear and do not have ABS/ASR issues. These are fairly aggressive race pads.