Subaru Master cylinder Sizing

Is this car a FWD or AWD car??? Those m/c's are perfect for an AWD car, if its FWD then its obvious a but too much.

Also there could be a possibility that there is too much rear timing, make sure that the front master cylinder has at least 5mm more rod length than the rear when the balance bar is at rest. That alone will fix some of the lock up. Don't turn the balance bar "all the way" that is going to create a lot of hysteresis and make the brakes act funny and bias migration and kill all the spectators.

As for the master cylinder reservoirs inside the car being the potential end of the world, well its a typical RA stupid and ignorant rule. I have yet to see any other sanctioning body bitch about it. Typical of idiots trying to be puritans. I would like to know where that expertise came from and what's the basis for it.

Car is awd, 2480 lbs without spare in the back. I made sure the rear is all the way in and the front rod is at least 5mm out.

Could it be pad contamination since the car sat for about 14 months?

I wasn't looking for lock up at the same time but even on pavement the rear will lock up and the front doesn't feel like its doing much of anything. I am going to bleed them again but the pedal feels rock solid and only travels 1" at the top, barely come off the brake light switch at the bottom.

There's something not right then, that setup is not too rear aggressive at all. What pads do you have in the front and rear? What type of center diff is on that car? You sure the pads are full bedded already? That's a very light car with 2480 so there should be even less weight transfer. Put the spare tyre is and everything as if you were about to start a stage when you test. How about the rake, maybe too much?

Don't go buying another master cyl, what you have HAS to work

Tyler, you abso-tootlely pos-a-twiwely 100 per cent certain you have the front/rear thing right..
MOST of the time guys get it backwards first time out.

You could just try the engagement and balance bar opposite of what you have and see/
Guys far smrater-er than me have done it backwards and been insistant that its "Logical", and din't even say thanks when I brow-beat 'em into trying the opposite..
It seems to be a odd thing but many people think 180^o off about brakes and hydraulics..

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Pads were bedded in as I used them for 4months on the factory setup.

Exactly there is no weight transfer! I can't brake and have it feel like the front dives.

Suspension up front is JVAB with 250lb spring. group n mount and group n front bushing. Sti control arms, waiting on funds for TSS. Ride height is 1.5 inches taller front and rear. Center diff is factory, front is Modena and rear is open until I find a clutch type subaru.

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john vanlandingham
It seems to be a odd thing but many people think 180^o off about brakes and hydraulics..

Lol people think bigger master for more powah.

He did say that it locks up except when the ballance bar is all the way one direction.

The master with the shorter distance between the pivot and master gets more mechanical effort correct?

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phlat65
He did say that it locks up except when the ballance bar is all the way one direction.

The master with the shorter distance between the pivot and master gets more mechanical effort correct?

I wanted to make sure of that too.

My cylinders from left to right: clutch .7" front .7" rear .813" it's better when the bearing in the balance bar is most of the way toward the left

I think I'm loosing touch, doesn't make sense. The setup the way it is should not lock up the rears like that. Especially with a center diff equalizing the torque split. What kind of pads are on there?

It's eBC yellows because it is what I had. Have a suggestion?

Well if its the same front and rear then its still not the answer to your problem. I will have to check your dimensions and do the math again, something's not adding up. Either that or you have other issues going on. Are the rears dragging by any chance?

As for pads, I don't know who makes better pads for those calipers but, carbotech might and XP12 or XP16 will do you well. Cobalt might also and they're even better, XR1 or XR2. Hawk as last resort DTC-60.

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FunctionAuto
Center diff is factory, front is Modena and rear is open until I find a clutch type subaru.

That's a really screwy diff setup. You went about it completely backwards. That thing's gotta understeer like a motherfucker. With a Subaru you should upgrade the center diff first, then rear diff, and save the front LSD for last and it's really kind of optional even then.

Absolutely upgrade the center diff before you do the rear diff. It will make the biggest difference in handling of the car, even more so than the front and rear diffs combined.

Just saw ACP post up piccies of the XD on FB - now with the brake res in the cabin. Assuming if a higher profile car is doing it, the rest of us should be ok as well.



Edit: can't see the pic for whatever reason...but there are three of 'em in the center of the "dash."



Edited 2 time(s). Last edit at 12/31/2012 01:42PM by DaveK.

Deriks M3 has the res's in the cabin. It has passed tech at RA and in Canada

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Doivi Clarkinen

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FunctionAuto
Center diff is factory, front is Modena and rear is open until I find a clutch type subaru.

That's a really screwy diff setup. You went about it completely backwards. That thing's gotta understeer like a motherfucker. With a Subaru you should upgrade the center diff first, then rear diff, and save the front LSD for last and it's really kind of optional even then.

Absolutely upgrade the center diff before you do the rear diff. It will make the biggest difference in handling of the car, even more so than the front and rear diffs combined.

I hadn't noticed a great deal of understeer but I will pay a bit more attention. It seemed once you had pointed the steering wheel and squeezed the throttle it would just pull you around the turn, and transitioning from a turn to the next the rear likes to really come out. But that may be because of the brake issue.

What would you recommend for a center diff for the 5 speed?