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Discussion Starter #1
My set up:

97 L Wagon. non-ABS:
Front: STi 4 pot calipers, SS lines, Hawk HPS pads, DBA rotors
Rear: STi 2 pot calipers, SS lines, Sti pads, STi stock rotors
Single stage booster - stock
Master cylinder: stock L
Proportioning Valve: stock L

Observation:
firm pedal, no excessive travel
The front brakes will lock up in a hard stop, but the rears never seem to lock up. The rear rotors are clean, so I know the calipers are not stuck. I end up flat spotting the front tires while autox-ing especially in short stop boxes.

What proportioning valve do I need?

The threads here have lots of conflicting info on this. Maybe I need a JDM valve from a type RA with no ABS? According to some info the drum brake valve should delivery MORE pressure to the rear so I should be locking the rears first, but no.
 

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They call me Garrett
98 RBP V4 STi Swapped RS
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4,110 Posts
I would definitely get the proper proportioning value!

The type R or type RA one is the one to get. GC with 4/2 pots and no ABS!

As far as locking up... I don't think I've ever locked up a rear wheel on tarmac (running Hawk DTC-30s front and rear). Our cars are very front heavy so a lot of the braking is done by the front.

I also have a V4 STi prop valve so the proportioning biases the front pretty decently.
 

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Baby❤Daddy
98L Wagon
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27,848 Posts
As far as locking up... I don't think I've ever locked up a rear wheel on tarmac (running Hawk DTC-30s front and rear). Our cars are very front heavy so a lot of the braking is done by the front.
you have ABS. you' shoudlnt be locking up a damn thing.
 

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Baby❤Daddy
98L Wagon
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27,848 Posts
98 L Wagon. non-ABS:
Front: bugeye WRX calipers, SS lines, Stoptec pads, Centric rotors
Rear: 98RS calipers, SS lines, Stoptec pads, Centric rotors
Single stage booster - stock
Master cylinder: stock L
Proportioning Valve: stock L

i have none of the issues you're asking about. my rears lock up with a quickness. well before my fronts. my braking is damn near perfectly flat. almost zero nose dive. (and yes, this can also be attributed to my stupid low suspension setup in addition to the brakes). an SVX master cyl may be needed for your larger 4/2's. i would say keep the single stage booster. pedal feel is sooooo much better with it. my pad wear is nice too in that they wear at the same rate front to rear. most vehicles will go through fronts about 2:1. makes it super easy for me to keep track of.

also, when you're saying STi calipers...you're meaning from our gen STI's right? not Brembo's..?

for shit's and giggles i tested my car VS my wife's (at the time) brand new '15 rogue. i stopped shorter by aobut 4 car lengths. which..comes down to (in my mind) my tires are better, and her shit weighs about 1K more than mine. i really thought with all the brand new bells and whistles stopping items..the results would have been opposite.
 

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Discussion Starter #7
I will order the JDM valve, it's not over the top expensive and get an SVX master cylinder too. Can't hurt to be more like the factory intended for braking. Maybe even a Grimmspeed brace after those.

For clarity I have GC STi calipers, fronts from a V3 and rears from a V5. Also lowered some on coilovers with more spring, bigger sways, more caster, more camber, ALK, STi control arms, 200 extra hp, etc.
 

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266 Posts
If you wander around junkyards in rural areas, look for a 90's postal legacy. They have 4 wheel disc and no ABS. Paid less than 20 for mine.
 

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Discussion Starter #9
No postal legacy in Canada, and the local yards don't even have a 90s Subaru. Japan parts is sending me one for a little over $100USD.
 

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Discussion Starter #10
Update:

I got the JDM proportioning valve 2763FA001 installed. Also went with a new MC from a 2002 TS non-ABS 26401FC010 that I got from Rock Auto on closeout for $23. Got both installed on Friday and went Autox-ing on Sunday. As a bonus it turns out that the original MC was starting to leak, so it was time to go anyway.
The braking is much improved. First off I noticed that the pedal travels less so braking starts higher up on the pedal. Next the pedal effort is harder, so more effort to get braking which was expected given the larger diameter bore size. The feel is much better. I didn't lock up in the finish box like I usually do. Only felt fronts lock up once going into a high speed left-hander and it was easily modulated.
I should have done this years ago and would have saved me a lot of flat spotted R-Compounds.

Thanks for the help all!
 

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99 22B replica
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1,316 Posts
I'm gonna revive this thread, especially since Brian is on it and he seems to know a hell of alot more about brakes than me, Ive got 4/2 pots on my 99RS Chassis with ABS... all new pads and rotors, the rear calipers are doing most of the work, the front rotors still have the cross hatching on them, doing some work but stopping is mostly in the rear. I have bled the brakes well, pedal feel is ok (adequate pressure). I would like a little more firmness but right now I'm just trying to understand why the rears are doing so much more work...
Our BMW has wayyyyyy firmer brakes, but the RS is on par with my 2000 Forester and my daughters 98 Forester..

Any advice? , New Master Cylinder? WRX proportioning valve? are they different than an RS?

Cheers!
 

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Baby❤Daddy
98L Wagon
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27,848 Posts
alright, here we go.

first, i think you still have air in the front system. causing the rear to do more work. i fuond this post here INCREDIBLY helpfull and have linked it every time with good results. used it myself on mattonthewater’s obs when i out on 4/2’s for him.

How to cycle ABS pump for bleed | MNSubaru

as far as the prop valve, most people will tell you to get one from a car designed with the 4/2 system. i personlly like a little more rear ward bias. i have gone from dums to disks in the rear. i get very little if any nose dive under heavy braking. i like it this way. you may want that weight shift. another plus is that all my pads wear at the same rate and not the normal 2:1 pad change ratio.

another thing to get is a master cylinder brace. i noticed a MASSIVE difference in pedal feel in just a simple upgrade. another big pedal feel item is SS brake lines to replace the soft spongey worn out rubber ones (i dont remember off hand if youve done this already).
 

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99 22B replica
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1,316 Posts
Alright B, I’ll read the link and try bleeding them again. Thanks for the input man. I’ve seen some braces for sale too. Might look again at that.
 

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06AW STI, 09 DGM STI, 00RSTI
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Going to rez this thread just to see if anyone's still following it and could help me with mine:


TYIA
 
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