Factory Calipers....what fits and doesnt.
 

So have been reading different things on what factory calipers and rotors will fit and what wont.

Can we get a list going of what does and does not work. I was looking for new BBKs and would really prefer to stick with some oem setup just so there are more/cheaper options on rotors and pads available.

I was looking at the willwood kit, but does that mean i am then stuck with willwood pads and rotors only?

I found these....
2006-2007 WRX 4pot/2pot
Will they work? Anyone have experience or know?

Thanks!

What is your actual goal in replacing your brakes with something else?

Looking for just a bit more stopping power. Plus now that i am ironing out my tune, would like to start doing at least 1 track day per month.

The stock system seems to fade now under hard driving. I have only noticed it once, doing some datalogging. Basically 3rd gear wot pulls then braking to pretty much stop. This after 10 minutes or so and the brakes felt bad, like scary bad. This was at about 280hp.

Just thinking of getting something a bit beefier. Now i am at about 350hp, so can only imagine it will be worse? Wan to fix it now, rather than have some break fade/failure on the track.


Was looking at some remanufactured brembos, or just do the willwood kit. I really like how easy it is to swap brake pads on the willwood.

Get some decent pads + upgrade your fluid, and you should be good to go for most track events.

-alex

This!

Bigger rotors and more pistons won't add stopping power or fade resistance, you need pads meant for track use and a higher temperature rated fluid.

HP doesn't heat up brakes, traction does. If you've got more grip than stock you need to beef up the brakes regardless of how much power you're making.

On stock pads I couldn't get ABS to engage with 225 width Dunlop ZII's unless it was COLD out, with just new fluid (ATE Super Blue) and pads (Ferodo DS2500's) it'll engage ABS even on a hot and sticky day.

Or look at it differently:

If you upgrade to a BBK and use factory Subaru fluid, your brakes are just as bad as before.

Since upgrading to a better fluid gives you fade resistance (one aspect of it, the other are pads and, to a lesser extent, rotors), then why not go for the cheapest upgrade first with the least hassle?

Brake lines also help immensely.

-alex

Why not AP Sprint?

Why the interest in the WRX 4-Pots? I know on the 05-09 Legacy GT they were actually a downgrade despite "looking" better. Might want to make sure they are even marginally better than stock...

-Pierce

Tires. /thread until....

Are you a track novice?

If so, pads, fluid and better tires (not R comps though).

If you are still having issues then think about increasing thermal mass. Which choice suits you best then depends on what you want. Everyone here probably knows where I stand on this one.. Once you have some experience and know that you really need more thermal mass then come back.

BTW, the calipers by themselves will increase feel a little and modulation a little, all else being equal nothing will change. No increase in thermal mass, etc. Bias may change a little so performance could improve or get worse. IIRC those calipers are less effective than our stock ones so Bias would move rearward, not ideal.

Bigger rotors = increase in thermal mass, which means more heat removal from the calipers/pads, which will decrease the duration that the calipers, pads and fluid have to deal with the heat generated from the friction of the pads against the rotor. So yeah, "larger" (quotes because diameter isn't the only form of larger) rotors will help prevent fade by being able to remove more heat, and more importantly, ABSORB more heat from the system, which is one of the primary jobs of the rotor.

Of course, bigger isn't always better and one can screw up a brake system pretty nicely with poorly designed or chosen "upgrades".

Well, sounds like just pad and fluid upgrade will work. Do i need to upgrade the lines to stainless as well? Maybe run that, and then later upgrade the rotors?

Will try that for a bit and see how it feels.

Track Novice. Never been on a track with a car. Use to race bikes alot, but i know, totally different.

Larger discs are not just about heat capacity. It increases the effective lever-arm of the brake system to give you a different pedal feel. I'm putting 330's on mine purely for this.

Doesn't matter how much heat the rotors can absorb unless they can keep the pad temps in a range the pads are happy with, and I can't imagine there's a rotor big enough to do that with stock pads :D

If you're overheating race pads with stock diameter rotors and aren't driving wrong, then sure there's a case for bigger rotors, but for 90% of the people out there they just need better pads and fluid.

Horsepower absolutely DOES heat up brakes! Braking from 80mph to 40mph requires 21.5% more energy than braking from 75mph to 40mph. BIG difference! More power requires more capacity to dissipate heat energy from the brakes, it's a fact.