2004 STI brembos to WRX swap [Archive] - TriStateTuners.com

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Khellen

07-08-2009, 10:51 AM

I'm bored so I decided to write a review for my current project of putting the 2004 STI brembos on my 2004 wrx. From all of the reading I've done before this there was a lot of confusion as to what was required....all you need is:

2 x STI rotors (2004 STI 5x100)
2 x Brembo calipers

I also installed:

1 x box of hawk hps pads
2 x Stainless steel brake lines

The project was started by purchasing two 2004 sti brembo calipers from another member. Upon recieveing them I wasnt told that the threads in the mounting holes were deformed. This is apparently a common problem with brembos as they use steel bolts and aluminum threads. The problem is easily solved by purchasing some helicoils and having a machine shop drill and tap them in.

Now that we've fixed that problem, the next problem is that my poor brembos were looking very tired after being used and possibly abused. Next stop was to take them over to bonehead performance located in warminster PA to be powdercoated mirror red. Unfortunately they have to completely dissaemble them to paint them properly.

After coming back from being painted they were taken to ryan at Area1320 who installed the new seal kit from subaru (80 bucks for the seal kit from subaru, ouch).

The install was ridiculously easy and I'm pretty confident anyone can do it. The hardest part is getting those rusty bolts off. Also note you'll need the STI mounting bolts and you cannot reuse your WRX mounting bolts. The STI mounting bolts are a tad bit longer. One problem I ran into during this process is that trying to find 2004 STI 5x100 rotors is retardedly hard if you dont order them online, so do yourself a favor and get that out of the way. I've still got to bleed the brakes but once that is done I'll update this post with a description of my new and improved pedal feel.

http://www.poorformance.com/brakes3.JPG
http://www.poorformance.com/brakes.JPG
http://www.poorformance.com/brakes2.JPG

PoorMan'sR

07-08-2009, 01:10 PM

ugh you sir are lucky, my brakes need to be upgraded real bad, the stock ones are terrible, especially when you start pushing more power, interested to hear about the new feel

ndubz

07-08-2009, 02:52 PM

Slotted rotors= cheese grater for brake pads......NEWB!!!!!!!!!

06WRBScoob

07-09-2009, 05:41 AM

Slotted rotors= cheese grater for brake pads......NEWB!!!!!!!!!

Unless you are using cheese for brake pads i would say your far off. They reduce fade and allow gasses to escape that would otherwise press against the brake pad, also with cooler temps they are resistant to warping. I have had Drilled & slotted rotors on all of my cars they last just as long as OEM

Khellen

07-09-2009, 09:09 AM

ugh you sir are lucky, my brakes need to be upgraded real bad, the stock ones are terrible, especially when you start pushing more power, interested to hear about the new feel

My stock WRX brakes were terrible in stock form. They were fading so much that it was scary. With better pads and SS lines it may have been a little bit better but in the long run they just wouldent have cut it with my goals. I'll have the brakes bled tonight or tomorrow morning and will definitely post an update.

Slotted rotors= cheese grater for brake pads......NEWB!!!!!!!!!

I really hope you arnt serious....

ndubz

07-09-2009, 02:36 PM

Unless you are using cheese for brake pads i would say your far off. They reduce fade and allow gasses to escape that would otherwise press against the brake pad, also with cooler temps they are resistant to warping. I have had Drilled & slotted rotors on all of my cars they last just as long as OEM

You dont see slotted on Lemans cars

Khellen

07-09-2009, 02:59 PM

You dont see slotted on Lemans cars

Really?

http://www.callawaycars.com/las/images/IMG_0820w.jpg

Extreme performance needs extreme braking ability. In keeping with enviable acceleration and top speed, braking ability is enhanced with the same package that the Callaway cars use at Le Mans. Only the brake pad material spec differs for road use.

http://www.callawaycars.com/las/C16components.htm

rodknock02

07-09-2009, 05:06 PM

Alot of lemans cars run slotted rotors.

howielong

07-09-2009, 06:08 PM

Bastard....

That is all I have to say. I'd love to do a Brembo swap on my car, maybe in a year or two.

R22B

07-09-2009, 06:47 PM

Slotted are actually the best kind of rotors to run is slotted. I think you may have it confused with drilled.

Drilled are by far the worst. The amount of surface area you lose is quite a bit. That and they seem to warp/crack very easily. I’d much rather run my stock rotors than drilled. Slotted allows for gases to escape without the loss of surface area.

If I ever upgrade my rotors, I’m picking up DBA rotors. I dig their kangaroo paw ventilation.

malloyboy1

07-09-2009, 07:12 PM

Khellen

07-09-2009, 07:42 PM

i found a full front and rear set of 04 brembos with rotors for 800 bucks i was gonna swap onto my 05 wrx but backed out cuz id rather a stoptec bbk

also what size are the wheels our running and what offset?

18x7.5 rota tarmac 2's. No idea what the offset is, bought them used but I'd imagine they are a pretty common stock offset.

JB'sLGT

07-09-2009, 08:42 PM

Brembos in just the front?

Isn't your brake bias all screwed up?

Khellen

07-10-2009, 12:40 AM

Brembos in just the front?

Isn't your brake bias all screwed up?

The WRX break bias is 80 / 20 so it's already very front biased. I hardly doubt the 2 piston brembos in the rear are much stronger then the stock wrx 2 pistons. If anything it might barely make a difference but not enough that I'll notice off of a track. I fully plan on doing the rears but they are a little more involving. Custom brackets that are like 400 dollars must be bought to use the rear brembos on the WRX.

Honest_Bob

07-10-2009, 07:09 AM

Yeah, its almost worth it to just buy a complete sti rear subframe. There is always the h6 rear upgrade...

Khellen

07-10-2009, 05:01 PM

Took the car out for a drive today. The brakes arnt as bitey as I thought they'd be, they definitely are stopping the car much faster at higher speeds but it's very linear....which is probably a good thing. I may just need to do a better brake bleed but I thought I got everything out of the lines. They arnt WORLDS better then my wrx brakes but it definitely takes a lot less effort as well as less brake fade. I'd definitely say its worth it. Two thumbs up! :)

Oh also, they look AMAZING in mirror red under my bronze wheels. I <3 my new brakes.

TROLL

07-10-2009, 05:17 PM

The front STi Brembos are an easy bolt on install, the rears arent. I believe there's an adapter bracket you can buy now to install the rears as well though but I'm not positive.

The stopping potential of your car is rarely determined by your brake setup, but rather your tires. Most crappy brakes can still manage to lock up the wheels (or engage ABS) and that tells you that the brakes are overpowering the amount of grip that the tires have with the pavement meaning the tires are the weak link, not the brakes.

Where the advantage comes in with an opposed piston caliper as well as a larger caliper/rotor is with things like pedal feel and heat dissipation which really only comes into play in road racing, and pretty much never on the street. There are a lot of reasons that these things are improved but if you want to really get into it check out the brake bible sticky in the brakes/suspension forum because it gets way too deep for me to brush over here.

Going back to pedal feel, you wouldn't 'feel' like the brakes are any better, for reasons mentioned above. However you may notice better pedal feel which is really important in precision braking and modulating the brake pedal very carefully. If you want to further improve that initial bite then pads are the way to go, and if you want to go further then stainless lines and upgraded fluid will improve the high heat situations.

Lastly, bedding in brake pads has a MAJOR effect on their performance and wear. If the pads and rotors aren't bedded in properly the brake performance can really suffer so look into that as well.

Honest_Bob

07-10-2009, 08:03 PM

Did you do ss lines too? They make a big difference pedal feel wise.

Khellen

07-11-2009, 09:12 PM

Did you do ss lines too? They make a big difference pedal feel wise.

I sure did! I'm not saying I don't feel a difference, it's just not as huge as I thought it would be. I need to stop riding in joe's GTR and M5, it's screwing up my guaging of performance haha.

TROLL

07-11-2009, 09:16 PM

The Brembos on my car feel sick... I have a feeling its either the fact that you're on stock pads (if you are), or that you didnt resurface the pads/rotors and bed them in properly.

DaveSTi

07-11-2009, 09:34 PM

Alright, guys..please..stop running HPS pads as "upgrades". I don't know where that idea originated from (possibly WRX brake pads?) but they are a downgrade from the stock STi brake pad. I've seen so many people run HPS pads on their car thinking they're an upgraded pad that its silly. Look into the MOT of the pad, coefficient of friction and you'll see its lower than the stock STi pad and not as rotor friendly as the STi ceramic pad. If you want an upgrade and want to stay with Hawk, you need to run HP+.

/soapbox.

Honest_Bob

07-11-2009, 11:18 PM

Good to know Dave.

Khellen

07-12-2009, 11:09 AM

The Brembos on my car feel sick... I have a feeling its either the fact that you're on stock pads (if you are), or that you didnt resurface the pads/rotors and bed them in properly.

I bought hawk HPS pads, and bought brand new STI stoptech slotted rotors. Maybe I didn't bed them in properly? Maybe I need to rebleed them, who knows.

Alright, guys..please..stop running HPS pads as "upgrades". I don't know where that idea originated from (possibly WRX brake pads?) but they are a downgrade from the stock STi brake pad. I've seen so many people run HPS pads on their car thinking they're an upgraded pad that its silly. Look into the MOT of the pad, coefficient of friction and you'll see its lower than the stock STi pad and not as rotor friendly as the STi ceramic pad. If you want an upgrade and want to stay with Hawk, you need to run HP+.

/soapbox.

This is pretty interesting, ah well, already in the hawk hps boat. :(

TROLL

07-12-2009, 11:34 AM

Well did you bed them at all? You haven't mentioned that.

And I have HPS pads on all 4 corners just for street use... I believe what you're saying Dave but I've been really happy with them for daily use. But wait, nobody brought up any type of pads before you did, are you psychic?

DaveSTi

07-12-2009, 12:57 PM

Khellen

07-13-2009, 09:35 AM

Well did you bed them at all? You haven't mentioned that.

Not yet, I'll do it tonight or tomorrow and see if that makes a difference.

TROLL

07-13-2009, 11:29 AM

I saw them listed in his first post and the talking about braking performance led to that soapbox vent. haha, my bad.

oh no its fine, it was good info and i actually didnt know it, thanks for the contribution :)

and khellen... dear god man. no wonder you hadnt responded to any of my bedding questions previously. did you resurface the rotors? you're judging a system that hasn't been set up properly... if you dont have 2 clean surfaces (resurfaced rotors and a new pad or cleaned pad surface, and they're not properly bedded in), then i would expect crappy performance from them.

Khellen

07-13-2009, 12:55 PM

oh no its fine, it was good info and i actually didnt know it, thanks for the contribution :)

and khellen... dear god man. no wonder you hadnt responded to any of my bedding questions previously. did you resurface the rotors? you're judging a system that hasn't been set up properly... if you dont have 2 clean surfaces (resurfaced rotors and a new pad or cleaned pad surface, and they're not properly bedded in), then i would expect crappy performance from them.

Calm down. How did I ignore you? I responded to your "did you bed the pads/rotors properly post. I've never even heard of bedding rotors before, but then again I've never owned a performance break setup. The rotors are brand new, so, no I did not resurface the rotors.

On top of that, how many new STI owners "bed" their brakes? I'm guessing not many.

DaveSTi

07-13-2009, 01:24 PM

hehe i did, but i'm prob. not the norm.

TROLL

07-13-2009, 01:30 PM

just saying... try it, you'll like it :)

i looooove the way my subaru stops, once i get some necessities squared away with the supra i'm going to be working on trying to get it to feel the same way. stock pads on there with plenty of life left but i'm going to have to upgrade to see what kind of difference that makes. already did the lines and the fluid when i had the system apart, and had the rotors resurfaced so the pads are def the weak link at this point.

Khellen

07-13-2009, 01:33 PM

TROLL

07-13-2009, 01:45 PM

No problem... if you havent already check out the brake sticky in the suspension and brakes forum... I'm sure there are links to some bedding recommendations there, and Hawk probably has some suggestions as well. The one thing I can add to that is just do it somewhere that you have a lot of space, highway preferably, and make sure to take a solid 15-20 minutes of just cruising after you've gotten them up to temp to allow them to cool down before you bring the car to a complete stop... they will be getting much much hotter than during normal driving.

Khellen

07-13-2009, 02:44 PM

Lots of interesting information from the stoptech portion of the brake sticky, good find! I especially liked the section on brake biasing. Explained a lot of things I didn't think about before.

Also found this pretty interesting, maybe I'll try some different pads....

Pad "bite" and release characteristics: For efficient modulation the pads must "bite" immediately on brake application and must release immediately when the pedal is released. This is purely a matter of pad selection. It is seldom a good idea to use different compound pads front and rear and never a good idea to use a pad with more bite or a higher coefficient of friction at the rear.

And this one is for Ndubz.

DRILLED VS SLOTTED ROTORS
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".

Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.

Khellen

07-13-2009, 02:49 PM

Brembos in just the front?

Isn't your brake bias all screwed up?

Found the answer to this as well....

When upgrading your front brakes, it is possible to size the caliper pistons and rotor effective radius to maintain the original brake system's pressure-torque relationship. Yea, it takes more engineering know-how and you can't sell the same part to everyone anymore, but you are not altering the base brake balance from what the OEM intended. This design philosophy stands behind every brake upgrade kit STOPTECH manufactures. Now, if you sized the front brakes correctly, why would you need to change the rear brakes? Good question. If there are no thermal concerns with the rear brakes (and on a front-engine street car there rarely are) then by installing a rear big-brake kit all you are doing is (a) spending money and (b) adding unsprung weight. This is not usually viewed as favorable, unless you like driving a heavy, expensive car.

Also pretty interesting....

Oh Yea - One More Thing…
Finally, under an OEM bias condition, the rear brakes only contribute about 15-20% of all the braking force the vehicle generates, and when you install sticky tires you actually DECREASE the amount of work they need to do. Why? Because at the higher deceleration levels afforded by race tires, there is more weight transfer taking place, reducing the normal force on the rear tires and increasing it on the front (remember F=µN from above?). If anything, we now want to decrease the rear effectiveness. Ironic once again.
Of course, if you decide to upsize your rear brake system components you can also impact the front-rear torque relationship, and consequently you can "bias" the "balance" more toward the rear. Go too far, and the rear brakes could lock before the fronts. Again, not the end result you were expecting, right?
It has been said that "The folks at STOPTECH should consider developing a rear kit to match their front setup. They'll be very happy with the performance improvement if done properly." Well, since our FRONT systems are designed properly, we save you the need to spend your money on the back axle.

Let's reword that quote to reflect the STOPTECH philosophy: "Our competitors should consider developing a FRONT kit to match their stock bias condition. They'll be very happy with the performance improvement if done properly, AND will save their customers the cost of a rear brake upgrade in the process."

PoorMan'sR

08-17-2009, 01:12 PM

doing this tonight, hope everything turns out right, heres a preview, i tested it to make sure it would fit yesterday before i made any commitments.

http://i277.photobucket.com/albums/kk55/PoorMansR/Brembo.jpg
http://i277.photobucket.com/albums/kk55/PoorMansR/Brembo1.jpg

Khellen

08-17-2009, 04:12 PM

Looks good! You'll really enjoy it, say goodbye to break fade!

PoorMan'sR

08-18-2009, 03:43 PM

front brembos are on, bedded them in last night, car feels amazing, the difference is incredible, i'm leaving for school thrusday so it looks like the rear brembos won't be going on till winter, but definitely a great upgrade,

TROLL

08-18-2009, 07:10 PM

Nice... did you get brackets for the rears, or what are you doing to fit them?

PoorMan'sR

08-19-2009, 02:09 AM

Nice... did you get brackets for the rears, or what are you doing to fit them?

im going to be getting the kit that fastwrx provides, so the adapter bracket and the custom dba rotors

Khellen

08-19-2009, 07:13 AM

PoorMan'sR

08-19-2009, 11:21 AM

What pads did you end up using?

im not sure, i'll have to ask my friend who gave me the brembos, the pads still had a ton of life left in them, put them on i think a month or 2 before the car was wrecked

IMPREZvWRX

08-20-2009, 04:43 PM

Are the master cylinders or brake boosters different between the STI and other Imprezas?

Khellen

08-20-2009, 10:06 PM

Are the master cylinders or brake boosters different between the STI and other Imprezas?

From my research before I did the swap....no. Unless you have 05-07 WRX, then you COULD go with a superior 04 WRX one. 05 WRX's got a better interior at the expense of the MC I guess hahaha.

Ahhhh the beauty of google.

02-04 WRX MT has the 26.99mm MC
05-07 WRX MT has the 25.4mm MC
04-07 STi has the 26.99mm MC

http://forums.nasioc.com/forums/showthread.php?t=1456630

http://forums.nasioc.com/forums/showthread.php?t=1256594&highlight=brembos

sherwood

08-20-2009, 10:23 PM

so wait ndubz finally shut up after he got played out? awesome...

nice pick up dude. looks real nice.

phate1229

08-20-2009, 11:59 PM

they were ferodo 2500 pads I believe, I've got the box at home somewhere but I'm pretty sure that's what I had on there.

Khellen

08-21-2009, 09:01 AM

they were ferodo 2500 pads I believe, I've got the box at home somewhere but I'm pretty sure that's what I had on there.

Nice, thanks!