Real STI BREMBO package upgrade - DIY

[eastendraceshop]

Great write up!! Thank you for this!

[Sam86]

Sorry for the big bump.

I’m currently doing this swap and am in the process of restoring my 08+ (black) sti calipers.

I’ve bought an OEM seal replacement kit as the dust boot was torn.

I’ve removed the pistons and want some reassurance or warning of whether they as safe to reuse (as I can’t source a placement locally and the cost including shipping is ridiculously high).
The outer surface of all the pistons are completely smooth and unscuffed, there is some slight scuffing on the bottom of the piston where it curves inwards (I don’t mean the base of the piston where it’s flat)I don’t believe this part makes contact with the outer wall. The scuffing is very minimal and I didn’t even notice it until closely examining each piston under a light. I don’t know how they would have even been caused either as they were already there when I removed the piston.

Will it fine as it isn’t the surface that touches the walls? Should I/ can I sand it slightly for peace of mind? It’s not sharp of rough but I can feel it slightly with my fingernail

Whilst I’m here is there any process people do to clean the insides of where the pistons sit outside of just a cloth and brake cleaner? After wiping the inside thoroughly it still looks dirty although it feels smooth and there’s nothing on my finger if I rub around the inside.

I’ll post a picture when I’m home

[Sam86]

Also a warning to people buying STI brembos (especially now for those looking to put them on the GEN 2)- there are Ali baba manufactures who make almost identical replica calipers that people paint and sell as refurbished OEM calipers. I had no idea this was a thing and fell victim to it.

I picked up on it a few days later and since I bought it from the guys house I was able to go there and confront him about it. But yea be cautious of people selling them rebuilt

[gen3v8]

Not trying to burst your bubble. The STI front calipers have a 40mm leading piston and a 42mm trailing piston. This is for more even pad pressure and wear. The calipers mount on the rear of the wheel stub axle on a WRX Sti.
When you fit these calipers to a BRZ/86 they mount on the front of the stub axle. So you have to put the left caliper on the right side to invert the bleeder valves to point upwards.
THIS IS EXTREMELY WRONG THEY DO NOT FIT BOLT UP PROPERLY THE LARGER PISTON NOW LEADS. See your picture. Not hear to argue or tell you about brake physics. Although it will work but not as designed.

[Sam86]

Originally Posted by gen3v8

Not trying to burst your bubble. The STI front calipers have a 40mm leading piston and a 42mm trailing piston. This is for more even pad pressure and wear. The calipers mount on the rear of the wheel stub axle on a WRX Sti.
When you fit these calipers to a BRZ/86 they mount on the front of the stub axle. So you have to put the left caliper on the right side to invert the bleeder valves to point upwards.
THIS IS EXTREMELY WRONG THEY DO NOT FIT BOLT UP PROPERLY THE LARGER PISTON NOW LEADS. See your picture. Not hear to argue or tell you about brake physics. Although it will work but not as designed.

Is that not the reason why people flip the bleeders? I don’t mean inverting the left caliper to the right as you described, I mean removing the bleeder, and the block off bolt and swapping them

[Trap63]

Originally Posted by Sam86

Is that not the reason why people flip the bleeders? I don’t mean inverting the left caliper to the right as you described, I mean removing the bleeder, and the block off bolt and swapping them

That's right!
It was sentenced
!! YOU NEED ONLY TO SWITCH BLEEDERS ON FRONT CALIPER FROM DOWN TO UP !!!!

only reading as well as...

[Sam86]

whilst looking on a thread I saw this (what looks to be) official Subaru document that detailed the changes made for the updated 2017 model. I found the paragraph about the brembo interesting as it doesn’t really seem to distinguish the performance package brembos as seperate to the WRX sti brembos.

Saw a lot of comments regarding the safety of sti calipers and how they’re dangerous to run as they’re completely redeveloped specifically for the BRZ/86 - and are completely different from using flipped STI calipers, when this document doesn’t entirely support that…

Note the second last sentence where they essentially say they are the wrx sti calipers painted red. Again I know they’re not the EXACT same but my point is I don’t see why they would even mention the STI calipers if these were developed from the ground up and were specific to the twins outside of the necessary rotor/ piston order changes to run them.

[gen3v8]

WRX STI Brembos are only drilled one end, only the bleeder is fitted. They have no block off cap or a joiner tube on the other end.

[Sam86]

Originally Posted by gen3v8

WRX STI Brembos are only drilled one end, only the bleeder is fitted. They have no block off cap or a joiner tube on the other end.

Are you talking about where the bleeder valves go? Because there is a block off cap at the opposite end that can be removed and swapped to the other end of the caliper. Unless it’s different for the pre-2008 STI calipers

[Sam86]

Finished the install of my reconditioned Black STI Brembos. I kept the original bleeders valves and pistons but replaced the seals and dustboots (was a huge pain to do compared to how people made it look on YouTube). Only real issue I ran into was getting a couple of the dust boots to fit flush, and there was an issue with the bleeder valve leaking brake fluid. Was able to stop the leak but the bolt was torqued down significantly harder than recommended. Not sure if it’s an issue with the caliper or the bleeder bolt itself as it was reused with just a vinegar bath to clean it up abit.

In terms of brake feel, if I’m honest it doesn’t feel that much different to stock. I didn’t have any adjustment period to get used to the brakes like it is when you drive someone else’s car. Felt the same as stock just smoother and slightly more precise/ firm as you come to a complete stock. Not mad about it as I liked the stock brake feel and was worried these would be too harsh. I swapped front and rear rotors, pads and added braided steel lines so I was expecting a more drastic feeling. I’m not running particularly harsh pads though so that could be why. Just standard brembo pads for the STI caliper, and DBA street pads in the rear.

I got the calipers fairly cheap so I don’t regret the swap. But I wouldn’t recommend this particular swap if your primary goal is performance. Probably be better looking at AP racing brakes

[gen3v8]

Originally Posted by Sam86

Are you talking about where the bleeder valves go? Because there is a block off cap at the opposite end that can be removed and swapped to the other end of the caliper. Unless it’s different for the pre-2008 STI calipers

Originally Posted by gen3v8

WRX STI Brembos are only drilled one end, only the bleeder is fitted. They have no block off cap or a joiner tube on the other end.

Genuine WRX STI BREMBO ^^^

[clio]

Originally Posted by Sam86

Finished the install of my reconditioned Black STI Brembos. I kept the original bleeders valves and pistons but replaced the seals and dustboots (was a huge pain to do compared to how people made it look on YouTube). Only real issue I ran into was getting a couple of the dust boots to fit flush, and there was an issue with the bleeder valve leaking brake fluid. Was able to stop the leak but the bolt was torqued down significantly harder than recommended. Not sure if it’s an issue with the caliper or the bleeder bolt itself as it was reused with just a vinegar bath to clean it up abit.

In terms of brake feel, if I’m honest it doesn’t feel that much different to stock. I didn’t have any adjustment period to get used to the brakes like it is when you drive someone else’s car. Felt the same as stock just smoother and slightly more precise/ firm as you come to a complete stock. Not mad about it as I liked the stock brake feel and was worried these would be too harsh. I swapped front and rear rotors, pads and added braided steel lines so I was expecting a more drastic feeling. I’m not running particularly harsh pads though so that could be why. Just standard brembo pads for the STI caliper, and DBA street pads in the rear.

I got the calipers fairly cheap so I don’t regret the swap. But I wouldn’t recommend this particular swap if your primary goal is performance. Probably be better looking at AP racing brakes

I think many people expect that larger calipers will increase the stopping power however there will be no difference to the oem units.
The 'performance' that larger calipers afford is the increased ability to repeatedly brake.

[Sam86]

Originally Posted by clio

I think many people expect that larger calipers will increase the stopping power however there will be no difference to the oem units.
The 'performance' that larger calipers afford is the increased ability to repeatedly brake.

Yea, I did expect a little more from the larger caliper, but was more surprised at the little difference from the braided lines, and new pads (previously my brakes were completely OEM, pads included) as I’ve seen people comment on the difference those should make