Wilwood BBK for WRX - Fit to BRZ

[JRitt]

Originally Posted by WilwoodDiscBrakes

Here is our 6 piston 12.88" rotor kit specifically designed for the FRS/BRZ/86 that fits inside the OEM 17" rims.

So what is Wilwood's official position on the use of this '08+ WRX brake kit on the FT86 chassis (the subject of this thread)? Is it safe? Has it been tested? How does it impact bias? Is it recommended?

[D1cker]

I'm not seeing the giant benefit to these. I understand they look good and the weight savings are there, but if the rotor is barely bigger and actually thinner then you're not really increasing thermal capacity?

If the bias is preserved or put more towards the rear then you're in good shape, but I see this as not being worth doing until that is figured out.

[SubieNate]

The aluminum hat has the potential to increase thermal capacity and efficiency but that depends on the amount of material there. Also, if the disc is floating it will be subjected to less stress as it heat cycles.

[WilwoodDiscBrakes]

A WRX kit that has a 5 x 100mm bolt pattern will fit but it’s not the best option for the FT86. Although the car is lighter than the WRX, the wheels and tires on the FT86 are larger in diameter. If the WRX kit 140-9193 was used for the street only and some autocross, it would survive; however, if you tracked this kit on this car, it would fail…. We want customers to use the 12.88” kit engineered specifically for the BRZ/FR-S and coincidentally don’t show kit 140-9193 as an option for the FRS/BRZ even though it can be bolted on.

[SubieNate]

Out of curiosity, how does a larger wheel diameter affect the brakes? AFAIK most WRX's run 225/45-17 or 205/55-16 which have practically the same outer diameter as our car's 215/45-17's (actually, ours are slightly smaller than the 225/45's). So if someone upgraded the wheels on the older WRX's to 17's (Extremely common) these brakes would fail? That doesn't seem right.

I'm not questioning that the bias etc isn't correct for this car, but a mechanical failure seems odd.

Nathan

[swift996]

Originally Posted by SubieNate

Out of curiosity, how does a larger wheel diameter affect the brakes? AFAIK most WRX's run 225/45-17 or 205/55-16 which have practically the same outer diameter as our car's 215/45-17's (actually, ours are slightly smaller than the 225/45's). So if someone upgraded the wheels on the older WRX's to 17's (Extremely common) these brakes would fail? That doesn't seem right.

I'm not questioning that the bias etc isn't correct for this car, but a mechanical failure seems odd.

Nathan

My thoughts too (but I think they are designed for the 16" wheels). All valid points but these guys sell brake kits after all. I'm not trying to push this as a kit, it's just what I took a risk on and fitted. I will update as time goes on. From my initial testing it seems like a great option for the street/autocross/occasional track guy. If I tracked my car often, I'd obviously opt for a more robust kit. These things crap on the stock brakes hands down. I'm just an enthusiast and have been modifying cars for more than 13 years now. I'm not the one that takes any liability or offers any warranty. I just enjoy sharing my insights. I've done brake swaps in the past (typically one OEM application to another).

[Anorexic 86]

I think it's closer to 11.5 lbs. weight savings per corner... not 16 lbs.

Complete OEM front: rotors, pads and calipers weigh 60 lbs. all together.

Complete Wilwood WRX front kit weighs around 37 lbs.

And the new front 6 pot FRS/BRZ Wilwood kit weighs 48 lbs. all together... saving 6 lbs. per corner.

[kanundrum]

Whoa nice

[Scooby South]

You guys realize...that the FT86 Stock front brakes ARE 08 plus WRX Brakes ..don't you??? Same calipers...and same MC... and Same Rotors.. after 13 years of experience in Subaru's...WRX/STi and now the FT86... I can say without one Shadow of a doubt..the the Wilwood kit will work on FT86's chassis.. Just like an 08 plus WRX/STi Rear Sway bar will work also.. You guys can criticize dynamics all you want.. and you can make all the assumptions that you want.. manufacturer or otherwise.. Of course they want you to buy Specific FRS/BRZ fitment... but fact of the matter is there's alot more options out there than people Realize. Just like the Factory 86 Rotors... you can interchange them with 02-07 WRX Rotors... that are 2.6lbs lighter per corner than the stock 86 rotor.. Same exact diminsions...

Marketing is a wonderful thing...

Bill

[Scooby South]

Originally Posted by Anorexic 86

I think it's closer to 11.5 lbs. weight savings per corner... not 16 lbs.

Complete OEM front: rotors, pads and calipers weigh 60 lbs. all together.

Complete Wilwood WRX front kit weighs around 37 lbs.

And the new front 6 pot FRS/BRZ Wilwood kit weighs 48 lbs. all together... saving 6 lbs. per corner.

Not true... I have the proof.. 16.75 lbs per Corner.. Stock brakes are about 31lbs per corner..

[Scooby South]

Originally Posted by JRitt

Are the pistons sizes and disc diameter combination on this kit sized to ensure proper brake bias on the FT86? Do the discs actually have any additional thermal mass vs. the stock discs?

Slapping on parts designed for a different platform may actually hurt performance more than help. Obviously, the weight savings is great, but your stopping distances may actually increase instead of decrease vs. stock. That's not something you can easily determine through seat-of-the-pants testing. You need data acquisition or a radar gun to do so.

We are talking about one of the most critical safety items on your car folks, and I don't see a shred of evidence that any scientific design or actual testing went into this kit with regards to being used on the FT86. I've seen this sort of thing on other forums over the years, and threads like this make me nervous as h*ll. Please guys, be careful!

YOU ...need to relax... not my first rodeo....

Bill

[swift996]

I unfortunately didn't get any performance data points from the OEM brakes but will try to find another OEM BRZ/FRS local to do a comparison.

The brakes are feeling great. They just renew my confidence in the car. It gives it a very inspired feeling. I wish this is how the OEM brakes were.

Also the noise that I spoke of has gone away, I'm guessing it was just the pads bedding.

[ABQautoxer]

Interesting about the diameter since most BRZs are using the same diameter we use on WRXs for autocross AND street use, 255/40/17. I find it interesting the concern of using a brake package designed for a heavier, more nose biased car with more power inappropriate. I'd love to see the math that could back up the claim so we could all understand.

[OrbitalEllipses]

Originally Posted by ABQautoxer

Interesting about the diameter since most BRZs are using the same diameter we use on WRXs for autocross AND street use, 255/40/17. I find it interesting the concern of using a brake package designed for a heavier, more nose biased car with more power inappropriate. I'd love to see the math that could back up the claim so we could all understand.

That right there is the concern; the brakes may not have ideal biasing since they were setup for a car with a ~70/30 brake split and closer to 60/40 weight distribution. I'm sure JRitt is giving the disclaimer as brake parts ARE among the more critical components where "following the rules" should be a priority.