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2x 2000 2.5RS (AW and SRP)
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92 Posts
Discussion Starter · #1 ·
WRX Brake Upgrade

Hello! Today, you will read about how to go from 2.5RS stock 10" brakes to the 11" WRX brakes!

The 02+ WRX and the 2.5RS share the same brake mounting brackets, and these are the parts that you'll need:








2 - WRX brake rotors
2 - WRX caliper brackets
17mm Wrench and Socket
14mm wrench and socket
Lubing Spray
Rust remover
Grease
Very ornate swear words
Possibly 4 new bolts: 17mm head with a thread pitch and length of 12mmx1.5

Here is a before shot of the wheel with the stock RS brakes.



First thing you'll want to do is to break loose your lugnuts and then lift your vehicle up in the air and remove your wheels.

You'll see here what the stock components look like.





The first thing you'll want to do is remove the caliper. There are two 14mm bolts holding the caliper onto the stock caliper bracket at the sliding pins. I couldn't get a good shot of it but they're very easily seen. Once you've done that, your car should look like this without the brackets and the brake pads. Don't lose the brake pad shims! You can reuse them!



After you've removed the caliper, set it aside, DO NOT LET IT HANG. SET IT AGAINST SOME OF THE SUSPENSION BITS. YOU DO NOT WANT THE BRAKE LINE TO STRETCH. The next part is probably the most annoying. Next remove the stock caliper bracket. There are two 17mm bolts holding the bracket in at the top and the bottom of the bracket behind the brakes. Here's a really crappy picture of the top bolt.



This is the part where the lube and the swear words are really handy. It's not common knowledge, but swearing at things is actually a lubricant. All of my power and strength and several hydraulic tools is what I needed to remove these bolts, only because these bolts had never seen the light of day and in its 8 year life span never removed.

Next is to remove the stock rotor. This will be tricky and will require even more swear words and anger should your rotors have been conjoined onto your hubs. If they are, you're going to have to use a hammer and tap away at the rotor until it loosens itself. Eventually, I had to use a floor jack pressed against the frame and the back of the rotor and tapped it with a hammer until it came loose.

Anyway, once removed, you've reached the halfway point! Hooray! Now's the time to take a quick break and clean your wounds, because you probably will have some by now.

This is the stock rotor sitting next to the WRX rotor:



And this is the stock bracket sitting next to the WRX bracket:



After you're done breaking, fit the WRX rotor over the stock hubs. If you buy your rotors from the dealership, they'll be covered in a grease. This grease is to prevent rusting. It should also have high temp paint on it. If you buy it from someone off the internet, get them turned and scrub the center and the vents free of rust and spray them with high temp black paint. 500 degrees high-temp paint should be good enough.



Then, remove the slide pins from the old bracket and give them a little grease and slide them into the new bracket and give them a few slides into the new bracket.



Set the new bracket onto the hub and bolt those 17mm back into place. Becareful not to crossthread!



As you can see, it's now night time, the problem was I didn't know I would have to replace the 17mm bolts, so I had to run around town looking for them as Subaru was closed. :(

Now you're ALMOST finished!

The RS brake pads can be reused, I still had a lot of meat left on mine, so I decided to reuse them. The WRX rotor will be thicker than the stock ones so you'll have to push your calber's pistons back into the caliper to fit the caliper back onto the assembly. Once that's done, it should look like this:



Go back and make sure everything is good and kosher and you haven't forgotten anything. Tighten the 14mm caliper bolts back on and that's it! Look how much of a difference the brakes have with the clearance of the RS wheels!



Look at how much of a difference in clearance there is!



Aaaannnnnnnnnnnnnnnnnnnnnnnnnd you're done.

Some good stuff if you ask me. If you have any questions just let me know!
 

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Dude, this is great. I have to do this as soon as my RS rotors go out. I got all the stuff, just waiting at this point. What 17mm bolts did you have to replace and why?
 

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2x 2000 2.5RS (AW and SRP)
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92 Posts
Discussion Starter · #3 ·
The bolts holding the caliper bracket to the hub. The ones I showed in the picture.

I had to replace them because they were so rusted. I broke them loose by using a floor jack against a 17mm wrench. I lift the car up off the jackstands. That is how stuck they were. Eventually after a lot of swearing and hammering, they broke loose. They were stripped and almost just solid pieces of metal.
 

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2x 2000 2.5RS (AW and SRP)
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92 Posts
Discussion Starter · #5 ·
Yes.

It brakes much better now than it did before. My stopping zones are about 20 feet further than Before.

However, the biggest gain I got was less brake fade. The bigger brakes gave me more surface area to dissipate heat and cool. In our last run, my friend with the stock brakes was fading halfway through our drive, while my brakes were still good and fresh until the end of our 4 hour drive through the mountains, THEN I started feeling the fading after having pushed very hard on them.
 

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99 impreza rs 2.5 black
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870 Posts
Looks good.

How about the rears?

Or changing out the calipers too?

I was going to start a thread asking whats the biggest brakes you could fit in the stock 16'' wheel. I just not done searching yet.

Thanks Joe
 

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2x 2000 2.5RS (AW and SRP)
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Discussion Starter · #8 ·
Looks good.

How about the rears?

Or changing out the calipers too?

I was going to start a thread asking whats the biggest brakes you could fit in the stock 16'' wheel. I just not done searching yet.

Thanks Joe
The biggest brakes you can fit under the stock 16" wheel are the MY06+ WRX 4 piston front, 2 piston rear brakes. However if you go with the 2 piston rear brakes, you'll want to switch it up to the Legacy H6 rotors which are bigger and vented or the WRX rotors as they are vented, though the same size.

The rears are the same size as the WRX, it's just that the rotors aren't vented.

I had thought about switching out the calipers because mine seemed a little crusty. I've done the dust boots on calipers on other cars, it's not fun. It is so not worth it in fact that I would rather go and buy a new set of calipers from the junk yard in better condition than actually replace the boots. Yes, I am willing to sacrifice longevity over rebuilding a caliper, that's just how I roll.
 

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07 sti/ 00 RS
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749 Posts
excellent write up, have that setup on my RS and its sick
 

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'97 Emerald Green GF4 5spd
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271 Posts
Awesome write dude!!! YEs, you will notice braking characteristics as going with a bigger rotors provides more braking surface and slightly more heat dissapation.
 

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1999 Subaru Impreza 2.5RS Blac
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113 Posts
I'm a little confused. If the size of the brake pads weren't changed, wouldn't the braking surface (where the pads touch the rotor) be the same? And can you use WRX pads with this setup for better braking?
 

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99 Impreza Outback Sport
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747 Posts
With your DIY all I would need to add are WRX calipers to upgrade my 99OBS 1 pots correct?

Also, are there certain model years which fit on the OBS/RS? I seem to recall there being a restriction of 04 or earlier.

Great write up btw. Thanks.

I'm a little confused. If the size of the brake pads weren't changed, wouldn't the braking surface (where the pads touch the rotor) be the same? And can you use WRX pads with this setup for better braking?

Ever use a crowbar to pry something open? Did you notice that the longer the crow bar, the easier it is to pry?

Or how about a breaker bar? the bigger the breaker bar the easier it is to turn that lug nut?

Well the further out you are from the axis of rotation the more torque you can apply to it.

It's a bit of a leap, but because the rototrs themselves are bigger the pads are farther out from the axis of rotation and are able to apply more torque for the same amount of force (your foot on the brake pedal). I believe this increases friction and allows you to brake harder.
 

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Premium Member
95 L, 96 OUTBACK
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2,918 Posts
This isnt a 10.2" this is 10.7" to begin with. The 10.2" is single pots. I know I upgraded to RS sized two pots from the singles.
 

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Katy Perry
2001 Outback Sport-Turbo
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3,671 Posts
does anyone know if this works on a 97 outback sport?
will these fit under 15" rims?
It will not work because the OBS has smaller, single pot brakes. If you can get 99+ RS calipers or WRX calipers, you can do this. I tried this weekend to do this mod but the 98 RS calipers are different. Luckily, I just picked up a set or WRX calipers cheap!
 

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'07 OBS
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90 Posts
It will not work because the OBS has smaller, single pot brakes. If you can get 99+ RS calipers or WRX calipers, you can do this. I tried this weekend to do this mod but the 98 RS calipers are different. Luckily, I just picked up a set or WRX calipers cheap!
Got it. Thanks!
 

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2000 RS sedan BRP
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345 Posts
Nice write up. Good advice about the cussing and the hammer. They both come in very handy when getting those rotors off. I did the rear Legacy brake upgrade while I was at it, and sprayed everything black to give it a more clean appearance.

 

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MY99 2.5rs rallybluepearl
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105 Posts
I got some wrx calipers/rotors and will be doing this soon! Thanks for the write up!

From what you said, I can use the pads from my RS brakes on the wrx brakes?
 

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'07 OBS
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does anyone know if this works on a 97 outback sport?
will these fit under 15" rims?

Anyone know if these will fit under 15" factory alloys?

I got a set of WRX front calipers, will get the rotors from Autozone (only $30 each!) this weekend.
I love me some brake upgrades.....
 
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