by "uofime-2" (uofime-2)
Published 09/29/2017 at 13:02
by "uofime-2" (uofime-2)
Published 09/29/2017 at 13:02
Tags: 2015 WRX
; brakes
; Track Day
; Subaru
STARS: 3
As is so often the case when you’re playing stupid games and win a stupid prize the only answer to you problems is to throw money at them.
After smearing one set of rear brake pads in one event then destroying a different set in the next clearly something needs to change. First and foremost never use that second compound again, but that sort of leaves me using the compound I had smeared the event before. After adding heat capacity to the front it seems clear the smearing issue is only going to get worse even with those. I do have the option of moving up a heat range in that compound but doing so also comes with an increased friction mu. That would further shift my brake bias rear and rom experience driving with those pads I can tell you that is not something I want. Given the ABS system in my car a portioning valve is not an option so I can’t adjust the bias. That doesn’t leave me a whole lot of options. Thus the solution: throw money at it:
Searching the forums as I sometimes do, I found a great deal on a complete upgraded brake set up. These are Fuji Heavy Industry (Subaru’s parent company) “2 pot” fixed calipers. These were OE on 06 and 07 WRXs in america and standard on many other years of WRX in the rest of the world, I believe some early versions of STI’s in Japan used them as well. The calipers are fixed as opposed to sliding which should give better brake feel and completes the conversion to fixed calipers that began at the front a couple months ago. More important than that is the rotors, which while they are only marginaly larger in diameter (292mm vs 278mm stock) the new rotors are vented and thus can shed heat much more quickly!
The person who originally bought this set-up of which I only bought the rear half was originally was planning to rallyX his car (rallyists like the FHI 4/2 set up because it lets you run 15" wheels that fit gravel rally tires), but realized they didn’t want to trash their new-ish WRX after like one event. As a result they came with 3 sets of pads to me these are stoptech sports which are cheap semi aggressive steet pads, HP+ which are good for autoX and ebc yellows that are good for light track. I’m not sure I’m going to care for those street pad, I’m probably too lazy to switch pads to autoX the twice a year I do it and I suspect I would destroy those yellows pretty quickly at a track day (after my last outing I’m not going to try). So.... I’m ordering a fourth set of pads, the same compound I liked before, Carbotech XP10 and we’ll see how long I can deal with the stoptechs for street driving.
While I had everything together I figured it’d be interesting to see what it weighed to compare to what’s on the car currently
We’ll call that 32.75 lbs. Won’t know what stock weights till I get it torn off (soon hopefully). These calipers and brackets are lighter, but I know the vented rotors will be heavier. I’m guessing this upgrade is going to be a net gain in weight, but hopefully not by a lot.
"ESSSIX GmbH - Accountant/Wagon Thumper" (thedlo)
09/29/2017 at 13:24, STARS: 1
I approve this message.
On the wagon my fronts are 6 pistons. Stops like hell, but I get a lot of nose dive. I’m going to be fixing that with stiffer springs, and 4 piston calipers in the rear. I’ve been sitting on those rear calipers for 2 years! I need to design a bracket for them, but time and life keep getting in the way. I also dont really need the added stopping power, I dont autoX or anything, but I enjoy improvements and stability LOL.