Truth about using STI Brembos on the twins

[CSG Mike]

Originally Posted by calispec

I had the same pad compound for the oem calipers and the Brembo's. I don't have any hard data or temperatures to show but i did experience fade with the oem calipers and didn't have it with the Brembo's (Same pad compound).

That being said I don't remember the temperature of the day for the runs but the sti rotors are heavier and larger so they must have a better thermal capacitance. I also like the feel of an opposed piston caliper vs a floating.

Changing the pads on the Brembo's are 1000 times easier and there is a wider range of compounds made for that pad size. There is also a pretty wide rage of aftermarket rotors for the STI so that opens some options up as well.

You will destroy rotors and with a 2 piece rotor you can replace the ring for relatively cheap. (Coleman)

Are the sti brembos the best brakes out there.. NO.. they are heavy compared to others. but for the price its a very good choice. JUST DON"T DO THE REAR.

on an aside..
be careful using different pad compounds for front and rear. each pad compound will have a different coefficient of friction as temperature raises. Cold you could have a rear bias.. as temperatures raises that bias could change to the front.. and then it could change back to the rear as you get them really hot..

you can also glaze the rear brakes first on a front biased car. There is more to it than just bias.

I'd dispute that... one 14mm bolt and pushing exposed pistons in, vs punching out pins and pushing opposed pistons in....

[gramicci101]

Originally Posted by CSG Mike

I'd dispute that... one 14mm bolt and pushing exposed pistons in, vs punching out pins and pushing opposed pistons in....

I've learned that with a sliding caliper, you can use a wood clamp to push the caliper against the rotor before you unbolt it, guaranteeing that the pistons go in straight. This is probably common sense, but I certainly felt accomplished when I figured it out.

[dejxx]

Originally Posted by protpibe

So you were running STI calipers?

Also, what pads and fluid were you running in your STI calipers that caused you to form this first hand account of life with STI calipers on the track?

I've never said anything about the STI swap because i never used them. I simply stated that (for me) i rather have a kit designed to work for this car than doing a swap, EVEN if its effective and very good for that matter.
No problems with the swap, just think that many people (like myself) would rather go on the BBK route for the confidence that the kit provides.

[CSG Mike]

Originally Posted by gramicci101

I've learned that with a sliding caliper, you can use a wood clamp to push the caliper against the rotor before you unbolt it, guaranteeing that the pistons go in straight. This is probably common sense, but I certainly felt accomplished when I figured it out.

I have a best practice of pushing in the pistons by hand. Once they "break" past the initial resistance, it should be smooth, and doing it by hand lets me know if there's anything fighting/resisting.

Obviously, you gotta wait till the brakes are cool, but yeah.

[cdrazic93]

Originally Posted by CSG Mike

Obviously, you gotta wait till the brakes are cool, but yeah.

Nope!! Get em while they're hot! Fresh off the track, nice and warm at 500* F!

[mav1178]

Not exactly STi Brembos, but I swapped a set of Endless Mini 6-pot calipers off a '02+ WRX onto the BRZ. My research was primarily focused on the equivalent systems between the GD WRX and comparible upgrades available for our cars.

Both Endless + Wilwood lists the same size caliper/caliper piston/rotor upgrades for the two cars, different part numbers but otherwise the same overall kit.

8 months and 10k street/track miles later, they still work well. Current tally is 8x track, 2x autocross, 1x drift events.

I'm about at the end of life on the current set of pads and have Winmax W5 on order.

http://www.ft86club.com/forums/showthread.php?t=49454

-alex

[goalbangee]

Originally Posted by CSG Mike

It is indeed car specific, per the Brembo engineers I spoke with. Brembo is very capable of making small runs of calipers sized specific to an application. They're very similar *looking*.

I would like to hear opinions from those of you who oppose getting STI Brembos on our BRZ, especially CSG.

From a simple search on AP Racing Website, BRZ and WRX have VERY VERY VERY similar parts numbers for Caliper Type, Brake Disc, Disc Mounting Kit and Brake Pads(Pads are exactly the same part numbers). Fronts have little different parts number, I'm assuming that because of the brackets. But please explain why these calipers are so similar but yet installing STI brakes on BRZ is dangerous.

Front

BRZ Front 6 Piston AP Racing BBK
https://www.apracing.com/product_det...32mm_disc.aspx

STI Front 6 Piston AP Racing BBK
https://www.apracing.com/product_det...9040y1003.aspx

Rear

BRZ Rear 4 Piston AP Racing BBK
https://www.apracing.com/product_det...35_x_24mm.aspx


STI Rear 4 Piston AP Racing BBK
https://www.apracing.com/product_det...24mm_disc.aspx

[mav1178]

Originally Posted by goalbangee

From a simple search on AP Racing Website, BRZ and WRX have VERY VERY VERY similar parts numbers for Caliper Type, Brake Disc, Disc Mounting Kit and Brake Pads(Pads are exactly the same part numbers). Fronts have little different parts number, I'm assuming that because of the brackets. But please explain why these calipers are so similar but yet installing STI brakes on BRZ is dangerous.

Similar part number is not the SAME part number.

Even the caliper physical shape is different:

WRX/STi:
https://www.apracing.com/drawings/P16.341.pdf

BRZ:
https://www.apracing.com/drawings/P16.318.pdf

Edit: no one cares about caliper size or shape. We care about rotor size, pad size, caliper piston size, and how this impacts brake bias.

-alex

[mrha]

After reading the posts it just seems like some people think that putting brakes that are perfectly safe on a WRX STI on to a BRZ would cause the car to crash instantly.

I think there's nothing wrong with people who want to install STI calipers onto their twin. I do think its wrong to create fear mongering when you don't have all the facts. Facts not opinions.

[lead82]

Originally Posted by calispec

I had the same pad compound for the oem calipers and the Brembo's. I don't have any hard data or temperatures to show but i did experience fade with the oem calipers and didn't have it with the Brembo's (Same pad compound).

That being said I don't remember the temperature of the day for the runs but the sti rotors are heavier and larger so they must have a better thermal capacitance. I also like the feel of an opposed piston caliper vs a floating.

Changing the pads on the Brembo's are 1000 times easier and there is a wider range of compounds made for that pad size. There is also a pretty wide rage of aftermarket rotors for the STI so that opens some options up as well.

You will destroy rotors and with a 2 piece rotor you can replace the ring for relatively cheap. (Coleman)

Are the sti brembos the best brakes out there.. NO.. they are heavy compared to others. but for the price its a very good choice. JUST DON"T DO THE REAR.

Were your OEM rotors drilled or slotted? I would not track my car very much, so a less costly alternative to combat brake fade would simply be to get slotted rotors and better fluid. Better for me to do that than to spend money for the swap and add mass just for the single benefit of better brake wear.

[lead82]

Originally Posted by mrha

After reading the posts it just seems like some people think that putting brakes that are perfectly safe on a WRX STI on to a BRZ would cause the car to crash instantly.

I think there's nothing wrong with people who want to install STI calipers onto their twin. I do think its wrong to create fear mongering when you don't have all the facts. Facts not opinions.

Same can be said for those currently running it without hard facts of its performance. I'd rather shy people away from potentially unsafe swaps until there are more hard data than for them to get a false impression of what works and what doesn't. All of these cautions are worse case of what could happen. When it comes to brakes, I'd much rather err on the side of safety.

[gramicci101]

Drilling and slotting remove mass from the heat sink (rotor) which makes it less effective at absorbing heat from the pads. You could make more effective change with fluid, titanium pad shims (debatable), and cooling ducts. Make sure you point the ducts towards the inside of rotor so you're directing air over the vanes, as opposed to pointing straight at the surface of the rotor.

[lead82]

Originally Posted by gramicci101

Drilling and slotting remove mass from the heat sink (rotor) which makes it less effective at absorbing heat from the pads. You could make more effective change with fluid, titanium pad shims (debatable), and cooling ducts. Make sure you point the ducts towards the inside of rotor so you're directing air over the vanes, as opposed to pointing straight at the surface of the rotor.

True, drilling and slotting will remove mass and thus thermal capacity of the rotor itself, but the small amount of mass removed with slots is IMO a small sacrifice to pay during dust build-up situations.

[protpibe]

Someone needs to rename this thread to "the speculation about using STI brembos on the twins"