What size brake rotors do I need?

[Kramerica]

The front pads wore down on my 2004 WRX, so I decided to take the opportunity to change all the pads and rotors. Seemed like a good idea...

I already had a spare set of Hawk HPS front pads, so I bought rear HPS pads and DBA 4000 series slotted/drilled rotors for front and back. The previous owner had put on TVR Racing big calipers on the front (they're red with silver lettering, and apparently are Brembo knockoffs if that helps). The rear ones are still stock. The front pads I had in my garage say they are designed for big Brembo calipers, so that makes a lot of sense.

Anyways, I had my neighbor (a mechanic of 30+ years) do the work for me. He put the pads on without any problem, but said the front and rear rotors are too small in diameter. So I tried to call back Fred Beans Parts (where I bought the stuff) for an exchange. The rotors they sent me are the correct stock size.

So, I'm assuming that the previous owner put larger rotors on there too and that's what threw off my neighbor. He said it looked like I had rotors designed for 15 inch wheels instead of 16 inchers. I'm assuming the ones that are on there are actually for 17s rather than 16s.

They are plenty willing to exchange the rotors for me, but neither them nor I know what size would be the proper replacement. I guess I could just put the smaller ones on there, but I'd hate to downgrade (plus, that's probably not going to work with the bigger front calipers).

Please correct me if I'm wrong on any of this stuff. I took some pics of my wheels/brakes. I don't have time to take the wheels off right now, but if you can't tell with them on, I understand and I'll try to get pics of them off later.

What size rotors do I have/need? Are these just STI sized rotors/calipers or what? Thanks in advance for your help, and please excuse me if I'm way off base on something. I'll try to provide more details if you need them.

Here's the rotors I bought: Link



FRONT:









REAR:





Again, I know it's probably hard to tell with the wheels on. If need be, I will try and get shots with them off.

[SeattleJeremy]

What does it say on the Red Calipers? We'll need to know who made the calipers in order to find out what big brake kit you have on the front.
The stock front calipers on 02-05's only have two pistons. Looks like you have a four piston setup.

The rear brakes look like the stock style. If you are doing the rear and the disks didn't fit then you likely have the H6 rear disk upgrade.
H-6 brake upgrade for dummies - NASIOC

[Kramerica]

The calipers say TWR Racing on them. I just talked to my neighbor, and he's saying that they line up perfectly on the rotors that are on there now.

I've been searching, and it's really hard to find these or any TWR stuff for that matter. I never heard of them before I got this car. I did find this though:

TWR rotors

I don't know if those are the ones or not. Thoughts?

[Kramerica]

So, if I have this H-6 upgrade thing, would these be right:

DBAs

or these

Cheaper DBAs

I'm looking specifically at the DBAs, because I need to exchange at the place I bought from, and I know they carry their stuff obviously. I've also heard good things about them.

Alternatively, they also carry Stop Tech and Racing Brake manufactured rotors along with stockies.

Any ideas on the front? Thank you.

Edit: Found the previous owner's e-mail address. I'll give him a shot, dunno if he'll remember though. I've had the car for two years now, so who knows how long ago it was he put the brakes on.

[Kramerica]

If it helps, the box for the front pads reads: HB193 HPS Hawk7266-2-EF 747-1ac31E

The pads themselves say: HB193f.670

I used the stock sized Hawk HPS pads on the rear.

[SeattleJeremy]

For the H6 rears, yes, DBA657X or DBA4657XS will work.

I'm having trouble finding much about the "TWR Racing" brake kit, other than some group buys from a 6 year ago.

[Kramerica]

Ok, thanks dude. Yeah, that's the same thing I'm finding on TWRs. I e-mailed the guy I bought the car from. Real shot in the dark chance that he'll remember this crap though.

Edit: Does the brake pad part # help out any in determining what the deal with the front calipers/rotors are?

Edit: Aha! This appears to be the kit - TWR 4 piston

Or maybe it's this one - TWR 2 piston

You think they're four piston though? I'll be honest, I don't know what I'm looking for to figure out the difference. The four piston setup says 310 x 28 will work. From what I can tell, DBA only makes 310 x 22 or 310 x 30.

[SeattleJeremy]

The you've got the 4-piston front set.
The 2-piston set you posted is the matching ones for the rear.

It's a shot in the dark, but, maybe Visionary Racing can get-a-hold of the disks for you.

[Kramerica]

Yeah, I could try that. Do you think the fronts would have to be 310 x 28? Would larger diameter probably not fit behind 16" wheels, and larger width be too much for the calipers/pads?

I don't know if the place I bought from will give a refund, or just an exchange. They seemed pretty reasonable on the phone though. I'll see what sizes/brands they stock.

[Kramerica]

Guy I bought the car from got back to me and confirmed what we had discovered. It's the H-6 290mm TWR rotors on the back and two piece 310 x 28 mm TWR rotors on the front.

Would 310 x 30 work, or would the calipers not fit properly over that? And 328 mm diameter would be too large for 16s, right?

It'd be a lot easier if I could just exchange from the place I originally bought rather than return and buy someplace else. DBA does not make 310 x 28 from what I can tell (except for throw away $25 rotors) only 310 x 30 or 310 x 22. They only carry DBA, StopTech and RacingBrake brands where I bought from. Not sure if either of the other brands are good, or come in that size.