Wilwood BBK for WRX - Fit to BRZ
 

First off, I can't take credit for the idea because I bought them from Scooby South because he wasn't able to use them in the STX class.

They are only the 4-pot calipers and the rotor diameter is only 12" (compared to the stock 11.5"). They shave 16lbs per corner and are about 1mm thinner. However, since they are designed for a 3300lb WRX, I'm not worried on a BRZ.

There was one exception to this kit, the bolts supplied don't work with the bracket, you'd have to order the 08+ specific bolts. The Part# is 230-10425 (they are 7/16-20 x 1.50 hex bolts - you will need 4) for those interested.

Kit part #140-9193 Subaru WRX 03+
http://i271.photobucket.com/albums/j...g?t=1363309031

The kit:
http://i271.photobucket.com/albums/j...g?t=1363311532

http://i271.photobucket.com/albums/j...g?t=1363311542

http://i271.photobucket.com/albums/j...g?t=1363309036

Install - I had Brady up at Pure Automotive install them. It was pretty straight forward. The kit comes with everything including stainless lines.

Review - The car has really come to life. The brake feel and bite is much improved. The car is so much faster on back roads now. I'm very happy with the purchase. I had a little bit of clanking noise (perhaps pad knock back) early but that has seemed to go away. It could have just been breaking the pads in. This is my first aftermarket kit. With BMW and Porsche you have a lot of OEM options.

The kit runs about $1K, which puts it at a price point between a stoptech slotted kit and the 6-pot 13" wilwood kit that runs about $1.7K. So this is a viable option for guys on a budget but want some improved performance.

http://i271.photobucket.com/albums/j...g?t=1364839362

FYI - That strut assembly is not mine
http://i271.photobucket.com/albums/j...g?t=1364839362

http://i271.photobucket.com/albums/j...g?t=1364839369

I'm sure from a roll they look real nice, but parked..almost stealth:
http://i271.photobucket.com/albums/j...g?t=1364859926

http://i271.photobucket.com/albums/j...g?t=1364859917

Driver's Side:
http://i271.photobucket.com/albums/j...g?t=1364859916

Passenger's Side:
http://i271.photobucket.com/albums/j...g?t=1364859921

Thats a great looking option for a realistic brake upgrade. Do you run your car in the snow? My only reservation about a wilwood kit is no dust boots.

And WOW is that a lot of weight savings!

Looks great. Thanks for sharing.

this is really good info thanks!

@PRORICAN

more affordable brake option

Looks like everything went together great. Do you have any plans on track days or autocross? Would love to get your impressions on how these do with proper track pads and hard use. Dropping 32 pounds of rotating unsprung mass is huge man!

I've been waiting to see this - thank you!

I'm in the Northern VA area now so not a lot of snow to worry about.


I'm doing Mid-Ohio June 10th. I'm hoping to make it to an autoX or out to Summit Point (road course) prior. I'm really waiting on my coilovers so I can put those on and my new wheels/tires. I've done some spirited driving with them but nothing heavy as far as track use. I think this will be good for the autocross guys and/or the HPDE/occasional track guys.

I put a little more detail in my build thread but I should mention the reduction of up-sprung weight can be felt immediately. The car feels more direct on turn in and more responsive to the throttle. It doesn't necessary feel faster but it feels more responsive for sure. I'll be dropping another 11lbs off the front axle when I get my FA20Club header in. So with my current upgrades, I'll be running with 50lbs or so off the front axle. I'm sure this is something fantastic for the autocross types.

This looks great and the weight saving is amazing... Will this change the break bias much?


Sent from my iPhone using Tapatalk

I'm still on stock springs/struts and there is a bit more dive. I plan to upgrade the rears to stop tech slotted rotors, some pads, and SS lines when it's time to replace them. They feel a little more front bias but nothing that makes it feel unstable. Just a hint of more bias but the OEM set up used the fronts a lot too.

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. :iono: 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!

^ The stopping distance is improved. I don't have any data but from a couple 30/60-0 tests they certainly stop quicker. As for the other questions, I'm not certain. The kit obviously wasn't designed for the BRZ, but being bigger and lighter is a plus for me. A lot of cars use the same rotors/calipers. My logic is if it can stop a 3300lb WRX faster, it should stop a 2700lb BRZ faster. However, specific to actual performance, I just have a feel, no data or extensive testing. The car still feels balanced, a slight bias to the front with the improved bite. It's light years ahead of stock, not sure how it stacks up to other aftermarket kits for the BRZ.

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?

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.

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. :)

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).

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.

Whoa nice

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

Not true... I have the proof.. 16.75 lbs per Corner.. Stock brakes are about 31lbs per corner..
https://sphotos-a.xx.fbcdn.net/hphot...65904651_n.jpg

https://sphotos-b.xx.fbcdn.net/hphot...19465975_n.jpg

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

Bill

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.

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.

But if the front brake calipers themselves are identical stock, it follows that an aftermarket replacement should work identically as well, to keep the same bias in the original vehicle would keep the same bias in the new vehicle regardless of the actual pressures involved. If the BR-Z is pumping x % less psi to the fronts, then if the calipers apply the same torque per psi then it should be fine.

Now, if the Wilwood kit is designed to be in a 4 wheel kit, then running without the rears could be an issue, or, if the rears are different on the WRX. But I'm not sure about that.

Nathan

^^^^ exactly

Bill

First, we have different rears from the early Impreza WRX so bias is already off. I believe we have 10+ Legacy rears or something similar. Second, piston diameter (or area) was not stated by the OP. I'm sure they're on Wilwood's site, but I'm too lazy to check. Third, related to second, we would need stock piston diameter/area of our brakes...which SHOULD be the same as the Impreza, but I'm not certain.

Note: it's possible the rear piston diameter/area hasn't changed from 2003 to 2012, but I wouldn't be sure about that.

How about you do the math and show me facts rather than speculate? I hate just because its brakes people lose their minds about basic facts. The factory setup is terrible so convince me this is worse and thus unsafe for street use.

Basically what I'm saying is that bias isn't just a matter of piston size/swept area. It's determined by the proportioning valve in the braking system as well. If the rear setup is different, who cares? If the front puts out the same torque as stock but increases the thermal capacity, it will improve the performance without affecting the bias.

So as long as the front setup retains the same torque output per psi, (Same balance of piston area, swept area, effective diameter etc) it doesn't matter that it's a different car. If our car has the same brake caliper as the WRX, and the same swept area and the same effective diameter, and the Wilwood caliper is designed to retain those things on the WRX, it will retain it on our car as well.

I'm not saying that's the case, but if the OE hardware is exactly the same then there's no reason to believe the Wilwood won't work if Wilwood did their homework the first time.

From NASIOCs brake math spreadsheet, you ignoramus: the 2002-2005 Impreza WRX has 2x 42.8mm front pistons and 4.460"^2 piston area across 2 pistons. The linked Wilwood kit has 4.12"^2 piston area across 4 pistons (4x 1.62" piston diameter). Likely the '10 LGT just has a different caliper bracket in the front and ahs the same 42.8mm pistons out front and 38.1mm pistons out back.

Way to not quote the facts and now my post is edited too while I added MORE math for your consumption, ingrate.

And the Wilwood caliper has 4x 1.62" piston diameter.




Choke on a rock.

In what way is the factory set up terrible?

Yeah that was poor wording, mainly I hated the stock pads, it was very easy to fade them.

The older WRX kit is 12"x0.81" rotor, the new BRZ kit is 12.88"x1.1" rotors. It's a pretty big difference in rotor thickness.

I've raced a 2750lb car with 12x.81" rotors, they are not going to have the heat capacity to hold up to real abuse. They would warp after a hard days use and I would change out rotors to complete the weekend.

Now if you were at a track that was easy on brakes and I can see using these to help acceleration. There are not that many people that change brake packages for different tracks other than pro race teams.

I don't understand how he's saying the diameter is larger... The diameter that is important is the outer diameter of the tire. That is the same (or nearly so) as every WRX that has ever been made in the states.

Nathan