Join Date: May 2007
Location: Bellingham, WA
'02 Impreza WRX
'85 Toyota Corolla
How To: Affordable ebrake solution for rear Brembos on WRX
As you may or may not know, STI's use a 190mm sized rear brake rotor hat / parking brake, whereas the WRX uses a 170mm. This poses an issue if you're installing STI rotors and Brembo calipers on your WRX, as your ebrake will have nothing to grab onto an thus cease to function. The front STI rotors and calipers will bolt on no problem (use 04 STI rotors as they are 5x100, or if you have dual drilled rotors, use those) so this post is only focusing on the rear.
I researched all my available solutions, and I came up with (what I feel) is the best, in terms of strength and reliability, and it happens to be the most affordable option.
First off, regardless of the route you choose to take, you're going to need to remove the rear dust shields from your backing plates. (I won't cover that, so go here for instructions: http://forums.nasioc.com/forums/show...74&postcount=2)
Now... as far are what options are currently available:
Option 1: DBA STI adapter rotors $375 + Kartboy Brackets $225
This option is by far the easiest, but convenience comes at a cost, as this is the most expensive option. These rotors are expensive and special order (can't pick them up from just anywhere). My only other concern is, I'd rather not use adapter brackets if I don't have to. I'd much rather choose a solid, one piece, OEM steel backing plate, which is why I didn't use caliper adapter brackets. Plus, I don't want to spend $225 and then have to modify them to make them fit Brembos.
Option 2: Godspeed Ring Inserts $350 + Kartboy Brackets $225
This option is still what I would consider an easy option, but it's still an expensive one for what you're really getting (plus, Godspeed is in the UK, you're paying about $50 in shipping). Godspeed makes these ring inserts for stock STI rear rotors that take up the dead space and allow you to use your stock WRX ebrake parts. The issue is, you're stuck to using stock type STI rotors (can't use lightweight 2 piece rotors) and any time you need new rotors, you have to get the new rotors drilled and transfer the ring... but you can pick those rotors up just about anywhere for cheap.
Option 3: Godspeed Thick Ebrake Shoes $250 + Kartboy Brackets $225
This is option is a bit more involved than the previous, as you're replacing the ebrake pads, but still what I would consider an easy option. Godspeed is the only company I know of that specifically makes thicker ebrake shoes for this exact application, but it's expensive with UK shipping. These ebrake shoes allow you to use any type of STI rotors, and since you shouldn't be using your ebrake for handbrake turns anyways they should last you the life of the car.
*Edit* It looks like KNS Brakes (US based store) offer pre-made thick ebrake shoes for $200. So for those that can't find a shop to do it nearby them, or don't feel like going through the effort, this is a good option. *Edit*
Option 4: Custom thick ebrake shoes $140 + OEM 06/07 WRX backing plates $130
This is the option I came up with after some research. This setup is the most difficult to accomplish, but it's still an easy task. Turns out, relining drum brake shoes is a thing, and since our ebrakes are nothing more than a drum brake inside our disc brake, I figured this should work.
I took my stock shoes to a local business (Unlimited Service in Bellingham, WA) and explained what I was doing. Jim told me they have 12.7mm (1/2") pad material that was flexible enough to adhere to my shoes, and he could arc them to match the new rotor. 2 days and $140 later, I had a set of thicker ebrake shoes. The new pad material is about 12.6mm thick, so that gave me about 2.6mm working material (1.4mm thinner than the Godspeed shoes). There was plenty of adjustment left in the ebrake mechanism, that this was plenty of material. I didn't shop around either, so you might even be able to get a set made for even cheaper.
Since I have an 2002 WRX, I decided to use OEM 06/07 WRX rear backing plates. They are the correct bolt spacing to bolt on the Brembo calipers and keep your ebrake/abs. At only $65 a piece from the dealer, these were even cheaper than using adapter brackets. If you are performing this work on a 2006 or 2007 WRX, this is an unneeded step, and you're finished at $140 ebrake pads. However, if you own a 2002-2005 WRX, you need to remove your hub in order to get to the backing plates. I currently have 170k miles on my chassis (hard miles, as this is my track day / autocross car) and since the rear bearings have never been replaced to my knowledge, and I was installing longer wheel studs, I went ahead and did them during this install. You don't have to replace them, but if they're old or worn, you probably should (there are plenty of threads that have people saying it's fine not to). Since they are a maintenance item on their own, I didn't include them in the cost of this project... but if you did, figure $100 in extra parts to do both sides.
Hope this thread helps some of you guys out!
Custom shoes sitting inside Girodisc 2-piece rotor:
Taken after installing the new shoes:
With the rotor install:
Last edited by BeBop86; 04-24-2013 at 02:58 PM.
Reason: Updated with more current info