will the sti brembos fit fr-s/brz?

[Turbowned]

I find it rather silly that Porsche and others still use cross-drilled rotors these days. A drilled/slotted rotor may weigh less, but there is also less rotor surface for the pad to bite down on. Since most pad compounds don't produce the gases they used to, it is my understanding that drilled/slotted rotors are functioning strictly for looks because the holes aren't needed to dissipate gases. The worst part is that when you replace pads, you can't machine the rotors on a lathe so they usually have to be replaced, too.

[Dave-ROR]

Originally Posted by Turbowned

JRitt, I understand where you're coming from for the most part, but couldn't some of those potential issues be remedied with a larger bore brake master cylinder (from an STi perhaps) and an adjustable proportioning valve? I still see the potential for ABS issues with this, I know.

Yes, but how many people will do that? JRitt comes from a similar car background (not in terms of work, but we've owned the same car and have seem some of the same stuff) as I do so we've both see what some people have done in the name of "brake upgrades". Even companies don't always do this stuff correctly, I remember when AEM released their BBK for Hondas and increased stopping distances due to the very things being discussed in this and previous brake discussions so expecting your "average joe" with no track/race experience to understand enough to diagnose and come up with a solution for these problems isn't something I'd bet on. JRitt and I talked about brakes on this car months ago and the MC and brake bias were some of the first things discussed but I wouldn't expect most people to go there. For minor bias differences just pads can fix it too, but that's a band aid IMO (not that I haven't used that bandaid..).

Apparently GReddy did this "upgrade" on their FR-S, with separate rear calipers for hydraulic e-brake. How would they bleed the calipers if the bleeder screws were at the bottom of the caliper - pressure bleeder? Considering they're running these brakes on their 600hp drift FR-S, I'm inclined to believe they work - at least somewhat! I sent them a Facebook message asking if they could shed some light on the subject.

Even with 600HP the amount of braking that car does isn't all that high. It's not seeing 45 minute hot sessions on the track, or more. We also don't know exactly what they've done, have they replaced the MC, prop, retapped the caliper to put a bleeder up top, etc.

From a cost perspective, IMO, the STI "upgrade" is simply NOT worth it. I priced it all out in threads months ago, and it just wasn't worth it to do it as correctly as possible.. and 04 STI blanks are expensive so consumables would be high.

As for bleeding, they could just have the calipers on the opposite sides, differential bore problems, but they'd bleed correctly. If you have the patience you can unmount them, flip them, and maybe get them sitting back on the rotor enough to bleed. I wouldn't deal with it myself, I'd rather just get something that's proper.

Again, I still find the '06-07 WRX calipers to be a more attractive option, but no doubt a lot of people will want to try the Brembos, and it would be nice to get all the facts straight for them.

If you want 4 pots, I'd agree. Again though, if everything else is equal including the functionality of the 4 pot WRX caliper, you won't change anything but looks, modulation/brake feel and a slight difference in pad wear.

In the end, it all depends on what your needs/reasons for replacing the brake components are. If you just care about looks, then the STI brembos work. If you care about street use mostly, the WRX 4 pots and STI brembos would "work", with the caveat that braking performance is likely to suffer so that drunk driver that was avoidable with the stock brakes may result in a crash. For track use, stock with cooling, good pads and lines, and if your needs exceed that setup, a properly engineered system would do the trick.

[Godzpeed]

I'm sure STI engineers would put stuff that "doesn't work" on their cars.....



seriously, how much on hand experience did you have with aftermarket and retro fitting braking systems??

[OrbitalEllipses]

There's no evidence that the brakes on the STI concept aren't from the Impreza WRX STI. It's a show car meant to showcase possible product development, not a full-blown race car or a street car that needs to function 100%. Read what Dave-ROR and JRitt have been saying; I expect people asking about the STI Brembo swap in the future to be banned as this information has been discussed to death.

@Turbowned: Was it necessary to come into another thread, spew more propaganda about magazines (saying the wrong things), more about GReddy, and continue to ask the same questions which were previously answered in other threads (WRX 4pots)?

[Turbowned]

Originally Posted by OrbitalEllipses

@Turbowned: Was it necessary to come into another thread, spew more propaganda about magazines (saying the wrong things), more about GReddy, and continue to ask the same questions which were previously answered in other threads (WRX 4pots)?

*shakes head* Yes, it was, as I am trying to get to the truth. Is it necessary for you to get your panties in a bunch every time someone asks a question or makes a small error? Probably not. Please don't make this like the "Do a search n00b WTF amirite" Honduh forums. Moto-IQ is one of the few sources out there that takes the time to look into all the gritty technical details of cars, and includes the best and brightest in the industry, so I tend to trust them; You just let me know when you know more about cars then they do.

Dave-ROR and JRitt, thanks for the insight! I agree that the average enthusiast isn't going to think about upgrading the BMC or adding a prop valve, and you're definitely right about the cost vs. benefit with these brakes. You're also right about the drift car not needing serious braking effort out there on the track; that had occurred to me as well - I think the e-brake is the only thing on that car taking serious abuse It looks like as far as the bleeding was concerned, they may have drilled and tapped the opposite end of the caliper for a bleeder screw, and put a pipe plug where the original screw was. Definitely not something Joe enthusiast would do, either. I would still like to hear from GReddy as to what their exact process for installing the brakes was, and what results they've had from using them. No doubt it's not a good swap for the average enthusiast to attempt, but there's a difference between "it's not the best idea" and "it can't be done".

[Dave-ROR]

Originally Posted by Turbowned

but there's a difference between "it's not the best idea" and "it can't be done".

Absolutely. I never actually intended to say that it couldn't be done so I apologize if I did state that. We've had so many of these STI brake discussions that I can't recall the details of them all now but I never believed it was impossible, just not really ideal

[Dave-ROR]

Originally Posted by Godzpeed

I'm sure STI engineers would put stuff that "doesn't work" on their cars.....

seriously, how much on hand experience did you have with aftermarket and retro fitting braking systems??

I've seen concept cars with calipers that didn't even have pads, lines, etc hooked up so I'm not sure how that's evidence of it being the best idea ever.

Again, doesn't work PROPERLY and it not being IDEAL compared to thought out upgrades (assuming it's even needed, I highly doubt I'll find a need for a BBK for the car under track use).

You could do the opposite and get rear calipers from a base 1988 Civic to work also, but just like current STI brakes that wouldn't be ideal either.

If you just want them for looks then by all means install them. No one here really cares but let's keep factual information alive and not just say "they are so much better than stock" when the evidence doesn't support that.

You could make them work correctly, retap them like Greddy may have done (assuming those are even STI calipers, I'm not convinced of that myself) and get 04 STi rotors for the front, the rear is a little more complicated and you'd want to address the rear if you want properly functioning brakes.

[Turbowned]

I'll wait to see if GReddy has anything to say - Still not gonna put 'em on my car. Next discussion: Porsche Cayenne brakes - will they fit the BRZ?



I actually have a set of these in my garage. Absolutely ridiculously huge! I'm hoping to find someone with an Audi who wants to try bolting them up under 19" wheels. Have fun with that!

[nibor33]

Originally Posted by Turbowned

I find it rather silly that Porsche and others still use cross-drilled rotors these days. A drilled/slotted rotor may weigh less, but there is also less rotor surface for the pad to bite down on. Since most pad compounds don't produce the gases they used to, it is my understanding that drilled/slotted rotors are functioning strictly for looks because the holes aren't needed to dissipate gases. The worst part is that when you replace pads, you can't machine the rotors on a lathe so they usually have to be replaced, too.

I was under the impression that Porsche was still supplying rotors cast with the holes in place, i.e. not cross-drilling. This would negate many of the drawbacks of cross-drilling. There is a minimal decrease in swept area, and the theory goes that it aids in dissipating the layer of gas that can get trapped between pad and rotor.

Anyway, surprised that an Audi salesman would criticize Porsche and claim that their rotors are crap... you can call Porsche overpriced, but they certainly are well engineered. Call me a fanboy if you wish.

Am I wrong about the Porsche rotors?

[Dave-ROR]

Originally Posted by nibor33

I was under the impression that Porsche was still supplying rotors cast with the holes in place, i.e. not cross-drilling. This would negate many of the drawbacks of cross-drilling. There is a minimal decrease in swept area, and the theory goes that it aids in dissipating the layer of gas that can get trapped between pad and rotor.

Anyway, surprised that an Audi salesman would criticize Porsche and claim that their rotors are crap... you can call Porsche overpriced, but they certainly are well engineered. Call me a fanboy if you wish.

Am I wrong about the Porsche rotors?

Porsche Rotors are cast with holes in them. For many years however they uses blanks on race cars, not swiss cheese rotors. Now they are using dimpled ones and some with cast holes but unless it's changed recently the endurance racing P-cars use blanks. I haven't checked for a few years though, JRitt and some others probably know.

Rotors cast with holes do avoid some negatives, but the holes are still stress risers and they still remove mass.

The gas thing is true, if you find some new old stock race pads from the 50s. Modern pads simply don't outgas like the old pads do.

Generally speaking rotors with holes are for looks. For street use they will function the same, but many have had 911 GT3 and similar rotors crack to hell from the holes after one DE weekend. A lot of the Porsches I see at events are using j-hook slotted or blanks. Very few are running OEM/OEM style rotors, at least around here.

[Dimman]

With regards to concept/demo cars having stuff. The early 'glass' BRZ concepts had the calipers on opposite sides, so take what you see with a grain of salt...

[OrbitalEllipses]

Originally Posted by Turbowned

*shakes head* Yes, it was, as I am trying to get to the truth. Is it necessary for you to get your panties in a bunch every time someone asks a question or makes a small error? Probably not. Please don't make this like the "Do a search n00b WTF amirite" Honduh forums. Moto-IQ is one of the few sources out there that takes the time to look into all the gritty technical details of cars, and includes the best and brightest in the industry, so I tend to trust them; You just let me know when you know more about cars then they do.

I know more about the car where the brakes came from than they do and I've repeated why it won't work properly a hundred times. If you could fucking visualize this differential bored caliper in three-dimensional space you'd have understood that ages ago rather than spamming your nonsense over and over about STI brakes, motoIQ this, Import Tuner that, GReddy this.

[Dave-ROR]

Relax.. step back from the ledge..

[Turbowned]

[OrbitalEllipses]

Originally Posted by Dave-ROR

Relax.. step back from the ledge..

Where's the :crazy: smiley? I think exams might break me.

Originally Posted by Turbowned

If you could see your ignorance the way I do, you'd be mad too.

[Godzpeed]

We've put on a 996 C4S front 4pot caliper on a Toyota Echo before...

Nothing can't be done!

and AFAIK, only the ceramic rotors crack after a few track days. I've taken my old 997 GT3 RS a few times to the track with the ceramic, and never had a crack. I've yet to take my RS 4.0 to the track. Most owners are recommending me to switch to steel rotors before I track my RS 4.0. But I don't drive as hard as some of the drivers, so I guess I couldn't have gotten it to crack yet.

[Turbowned]

Well then OrbitalEllipses, I think it might be in your best interest to create a sticky for all future inquiries, so that you don't have to give out 1,000 enraged replies when people inevitably ask if it can be done. It will benefit the community and keep your blood pressure lower! Perhaps include a cut-away diagram of a differential-bored caliper so us less-geometrically-inclined can visualize it, and stop calling us all ignorant. Win-win? I think so.

[Turbowned]

Well, this might be all the proof we need that they don't work right; WTF is up with those rotors?

[Racecomp Engineering]

Holy carp! THAT is not a good look.

- drew

[Dave-ROR]

Originally Posted by Turbowned

Well, this might be all the proof we need that they don't work right; WTF is up with those rotors?

Backing plates of the pads grinding through the rotors.

Those don't appear to be differential bore calipers.. ie not STI calipers.

[OrbitalEllipses]

Originally Posted by Dave-ROR

Backing plates of the pads grinding through the rotors.

Those don't appear to be differential bore calipers.. ie not STI calipers.

They probably are; the outer bore shapes are not different, only the interior piston bore is different. I just packaged my calipers up so I can't take a look at them, but I'm pretty sure the outer shape isn't different from forward to trailing piston.

[Dave-ROR]

Good call