STI Master Cyl. and Brake Booster SWAP SUMMARY for LGT

Fen, not to beat a dead horse on this topic but just thought of something. I think the rest of us are looking for a more sporting and athletic brake feel. We get that along with an abnormally stiff pedal comparatively to OEM brakeing system. If you have ever driven aftermarket BBK/track setup, a stiffer pedal with higher precision potential is preferred. NOT saying the Sti booster/mc is perfect, but it comes way closer to achieving that feel then any magic combination of stiffeners and braces on the OEM booster and master.

Still waiting on an answer from John Mueller. He's been busy. But according to him, and when we talked in person, he was wondering what was wrong with the brakes. He's the successful racing son of a racing legend. In fact, he was joked about trying to buy a Subaru. Twice. "I never made it past the test drive," he said. Great cars, he said, but flawed.

 

Anyway, as for the BB and MC, to me, it's the equivalent of cutting your stock springs so the car will be lower and bouncier. I'm still wondering if I've got a bad install, or wrong parts because there's nothing sporty or athletic in my setup.

 

- Jason

The only thing that could really be off on your install is the booster rod length.

 

Make no mistake, if your pedal is immediately firm and pad engagement is quick but the pedals requires more pressure to create the same braking force as previous, the install is very much probably right.

 

Im not a writer, but myself, my family, and my extended friend group have been consumers of tuneable/fast/fun cars for over a decade. I would hate to count up all of the stock, modified, and/or other cars that i have driven both on the street and on the track. Always with the intent of being critical of car, trying to learn and consume what is right, wrong, good, and bad. This may just be a flat difference of opinion. Its simple for me, between driving the OEM and STI master and booster, i know which brake pedal i would prefer to be behind.

Just did this install along with new SS lines and Super Blue fluid. The brake feel is vastly improved. The combination of moving away from the SS lines and adding the larger bore master cylinder seem to have mostly cancelled out any change in braking effort.

 

The only part I had trouble with was the check valve. On my first attempt at shoving it in I damaged it and it would no longer hold boost. I ended up going with the S13/S14 Inline Valve. Slightly more than the vacuum hose but overall a more elegant solution in my opinion.

so will this work with a 5eat? all of you posting seem to have a mt

I don't see why it wouldn't,be the first to try and then tell us haha.

My 2006 Legacy GT is a 5EAT. No issues at all w/ fitment.

so will this work with a 5eat? all of you posting seem to have a mt

 

5eat has VDC correct?

 

Seen it mentioned several times in this thread that for VDC cars the tube and fitting sizes are different and do not mate up to the sti master cylinder.

 

Has anyone done this swap on a LGT 5eat? Mushy brakes have to be my biggest complaint with this car.

Some 2008 (don't recall the actual VIN # change-over) and all newer 5EATs are VDC.

Some 2008 (don't recall the actual VIN # change-over) and all newer 5EATs are VDC.

 

 

Anything else out there to improve the pedal? Have heard alot of mixed results with the ss lines and mc brace.

I have the sti master and booster and it improves the feel vastly. I also went from stock blank rotors and akebono pads to power slot rotors and stop tech pads and with the stop tech pads the feel is much better.

My current set up is powerslot rotors front and rear,stop tech street performance pads front and rear,sti master and booster with ate super blue. I can honestly say that it was a substantial difference with the sti parts. Not like it helps you stop any faster but the pedal feel is so much better. Soon ill be switching to wilwood calipers up front,SS lines (front) wilwood bp 10 pads (will get track pads later) and te same rear set up and will post if its any different.

 

Whether its worth it is your call,I paid under 100 for the sti master and booster off eBay and would say it was money well spent.

I wanna know people found these for 70 bucks. cheapest I can really find is 125 with shipping.

 

lol I'll sell you mine for 70. I'm in NYC tho

Is this an STI booster? http://www.ebay.com/itm/261187594827?item=261187594827&viewitem=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr

Looks like it. Sti masters are stamped with the 1 1/16.

Hehe. I bought mine from him. He sent me a wrx brake booster. I emailed him the difference in wrx and sti and so he sent me an sti specific one and told me to keep the wrx one. Good customer service, but I think he's a one man show.

He said part # on the booster 864-06319 MW

3828

is this the right part?

Look at my post earlier in the thread

Has anyone tried this with a 2008+ STi booster?

 

Has anyone tried this on a 5th Gen LGT?

 

Our M/C is different than earlier LGT's, both of our hydraulic lines come in from the right instead of top front and left side. Is it possible to retain the 5th Gen MC and just utilize the STI booster. I realize that part of what is making the difference in pedal feel is the 1-1/16" MC on the STI, but I am working on getting specs on the 5th Gen MC bore size to see what it is stock.

Is it written on the MC like it is on the STI one?

I looked around a little, but need a mirror and better light. Will work on verifying 5th Gen MC bore size tonight.

 

It looks like the 2008+ STi uses the a very similar booster to the 5th gen, a Tokico ZG versus the ZD or EK, and a 15/16" MC. Can anyone confirm?

just installed it on our 05LGT. Brake feel is more consistent, no more "dead spot" at the top of pedal. Definitely improved feel. I can imagine it would be even better with some slotted rotors and decent brake pads.