brake uprgrade question

[mesoslow6969]

i will be upgrading my brakes soon. i have the touring wagon with abs, so i already got the "better brake" system on my car.
By next year i should be pushing about 300hp to the wheels. i was wondering if you recommend a bigger brake set up like the 06+ wrx 4 pot calipers, brackets, pads, rotors? or do you think just slapping some better pads on my oem calipers should be good enough for the amount of power for my purposes?

this will be my daily, but will be having fun at auto cross events every so often.

i understand about wheel fitment and making sure that the rotors i get should be 5x100.
Also, i know if i do rear calipers i "should" get the rear hubs for the whole parking brake "problem". Besides, i need a new e brake/cables anyway because mine doesnt work. so if i did the swap, i would have to get new lines anyways.

i just don't want to get bigger brakes if pads, rotors, ss brake lines will be just as good. let me know what you guys think.

[Legacy777]

Honestly, it depends on what you want to do. Auto-x doesn't really require massive big brake kits like say track racing does. You don't get up to high speeds and the run is over pretty quick. Some good performance high friction pads should do similar in an auto-x event as a bigger brake setup with normal performance pads.

There are some benefits to going to the larger setup, but you should also consider any changes to your brake bias. The 4-pots with the 2-pot rears are a pretty nice setup, and you can use kartboy's adapter plates to use the 2-pots without replacing the rear hub. Check out my brake math spreadsheet to look at what changes to brake torque occur with different brake setups.

http://bbs.legacycentral.org/viewtopic.php?f=8&t=25054

[mike-tracy]

There's a set of Legacy Spec-B brakes for sale in the parts shed. They're larger than the 4/2pots, and cheaper by a big margin.

[mesoslow6969]

will those legacy spec b brakes bolt right up all the way around? or do i need to get adapters for the rears? by the way thanks guys for the input. trying to budget my money without overdoing something that is not necessary.

[mike-tracy]

They're sold. The fronts fit for sure, and the rears you'd have to bend back or break off the dust shields since they're too big.

[mesoslow6969]

yeah i just got a pm that they were sold.

i may just buy reman ones from an auto parts store. if they all bolt up without needing extra brackets or what not then, i'll just go that route.

do i need to get the rotors made for the spec b then? or do i need to do those hybrid rotors? the newer legacies are still 5x100 so i'm guessing just use the spec b rotors up front, but the rear rotors is where i'm not sure due to the parking brake.

[Legacy777]

Other thing to keep in mind is that with bigger brakes, you need larger wheels to clear the brakes.

Regarding the rotors, I'm guessing the spec b has the same size rotors as the legacy GT. If so, you can go to the brake data tab in my spredsheet and it lists the rotor sizes. You can use that to see what other models may come with that size rotor.

[mesoslow6969]

ya i got some 17x75 rims +44 offset. hopefully they clear the brakes. thanks again josh for being so helpful.

[05LGTLtd]

Legacy GT brakes and Spec B LGT have the same brakes, 05-09. They should fit under 17x7.5's.

Fronts and rears should bolt right up. It's a lot of brake in the set up. I've toyed with going to brembos on my LGT, but the performance gain is minimal. Mainly, if your having fade it's time to go to brembos on a LGT. Stop tech has a newish pad out for the LGT if you burning them up, might save you some over hawks.

[05LGTLtd]

Oh, one more note: LGT's have a known "soft brake pedal" feel. Some folks are really bothered by it. You can bleed them, upgrade fluid, SS lines, performance pads and it gets a bit better. It turns out we were cheated on the MC diameter. Our big heavy cars with big brakes got the smallest MC subaru puts on a legacy/impreza. Some folks have had good results going to a 04-06 STi mc/bb. ( you have to change both, and add a check valve, on the lgt at least)

[mesoslow6969]

thats good to know. thanks. I'm still putting the brembos on though, since i got them with the swap. lol might as well take advantage of everything. =)

[05LGTLtd]

You'll need spacers or different wheels to clear brembos most likely.... They won't fit under the stock 05-06 LGT wheel without spacers. Some 17x8's will work, there's a list on nasioc.

[Legacy777]

Oh, one more note: LGT's have a known "soft brake pedal" feel. Some folks are really bothered by it. You can bleed them, upgrade fluid, SS lines, performance pads and it gets a bit better. It turns out we were cheated on the MC diameter. Our big heavy cars with big brakes got the smallest MC subaru puts on a legacy/impreza. Some folks have had good results going to a 04-06 STi mc/bb. ( you have to change both, and add a check valve, on the lgt at least)

Supposedly, Subaru indicated that the 05 Legacy brake booster was the stiffiest out of all the brake boosters. However I agree, the MC diameter size is seems a little small for the volume requirements. The size of the MC also depends on the flex of the calipers, and I seem to recall that the flex was reduced, but probably not to level a "performence-minded" individual would like.

Where does the check valve need to be installed and why does it need to be installed?

[05LGTLtd]

There is a check valve in the vac line from the bb to the intake manifold on the sti. The legacy gt booster has the valve in the bb. If you just swap the bb from a sti into a lgt you have no way to keep boost in the manifold from bleeding vacuum out of the bb. ie boost to brake is oh $&@! moment!

[05LGTLtd]

Should have said this earlier, but the STi MC won't bolt up to the LGT BB, that's why you change both on the LGT. On a earlier legacy you can probably just switch the MC out and avoid the check valve deletion problem.

[mesoslow6969]

i got the brake booster and master cylinder from the sti. hopefully it bolts right up. if not, i'll take your advice and swap out the mc. i still haven't ripped my car apart yet so, i'm still going to be testing things out.

[Legacy777]

On the earlier Subarus, including the first gen Legacy & mid 90's Impreza & Legacy, the vacuum check valve is in the hose coming from the intake manifold.

[mesoslow6969]

but if i'm using everything from the sti, will that matter? i'm kind of becoming confused. I still have to go to the dealership to get vacuum hoses and hopefully theyll have exploded diagrams of all the hoses. I'll keep an eye out if the stis have check valves in their hoses. if I end up having to do a brake booster/master cylinder hybrid, i'll make sure to get the hose meant for my car with the check valve. I hope I don't make a mess of things.. lol