T fitting instead of prop. valve, what is the rational? Options

[DanT]

Ok, I know this has probably been discussed in many threads before. But, what is the reasoning for replacement of the Prop. valve with the "T" fitting for the rear brakes. Does the prop. valve cause more line pressure to the fronts or the rears when it is operating properly? I want to understand the engineering aspects of this modification.
I will be running "M" calipers with mythical billet hubs in the front and stock 914-4s in the rear.
thanks (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

[andys]

QUOTE (J P Stein @ Dec 2 2005, 09:22 AM)

QUOTE (andys @ Dec 2 2005, 08:52 AM) What do the garden variety 911's use? I have '89 Carrera brakes, front and rear, ready to install. Did that car have a prop. valve? Do Carrera owners mess with their prop valves? Do they experience spongy pedals? Of the street 911's I've ever driven, I always thought they had excellent brakes. Anyone? Andys The corelation between a Carrera brake set up and a 914 with Carrera brakes wouldn't seem to be straight across. The Carrera has more rear weight bais, bigger tires rear to front, undoubtly transfers less weight to the front during braking...The only thing that does work is a reasonable compromise between braking force caliperwise front to rear......it's close enuff to work out on a 914.....if you have a adjustable valve as less pressure will be required in the rear on a 914 due to the reasons above.

Re-reading my post, I see I mixed a few things together, perhaps confusing the intent.

JP, you're absolutely right. Two different cars with two different sets of dynamic conditions. 911 = more rear weight bias = different brake biasing requirements than the 914. BTW, I will be running 255-17's in the rear.

Teener's generally seem to complaing about the prop valve, yet 911's use them throughout, ergo my comment "Do they experience spongy pedals? Of the street 911's I've ever driven, I always thought they had excellent brakes." So what's the difference?

Andys