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Project Subaru WRX

Part II: Brakes, bars and other detail work

Dave Coleman
Aug 23, 2003
0209_01z+subaru_wrx_sedan+front Photo 1/14   |   Project Subaru WRX

Two months ago, you saw Project WRX take on the mighty Mitsubishi Lancer EVO VII in the most hotly contested comparison test in the history of this journal. We gave the win to the EVO, which frankly wasn't all that surprising. Fact is, we knew going in that Project WRX wasn't ready to take on a full European-spec Lancer, but this car is so much fun none of that mattered at the time. Even in defeat, our love for this car continues, and our drive to improve it further is stronger than ever.

That's how things have been going with our WRX. There doesn't seem to be anything it can't handle. Witness this month's lead photo. Sure, full throttle, opposite-lock oversteer with a bike on the roof isn't something we do every day. But, given the WRX's brilliant chassis, bulletproof drivetrain and endearing practicality, we wanted to make a point. This is the most usable fast car to ever grace our fleet. Plus, mountain bikes make cars look tough.

0209scc_projwrx02_z Photo 2/14   |   This brake kit, designed to fit under 16-inch wheels, comes complete with Brembo calipers, AP rotors, pads, fluid and lines.

Big Brakes
We've said before that we plan to retain our WRX's gravel prowess, which requires us to keep a set of 16-inch wheels on hand for gravel duty. This wheel choice limits our brake options. To our knowledge, there are only two aftermarket brake kits available for the WRX that fit under 16-inch wheels. One from FHI and one from Rally Performance. And even then, wheel choices are fairly critical for proper caliper clearance. The Rally Performance kit won't fit with the stock 16-inch wheels. This month, Project WRX appears with Tecnomagnesio TM Racing wheels, which came from Rally Performance, the same source as the brake kit. The wheels are relatively heavy at 22 lb each, but, being a true rally wheel, handle gravel duty well.

Rally Performance's brake upgrade includes Brembo calipers, Pagid pads and AP rotors as well as four stainless-steel lines and Silkolene racing brake fluid. The 12.0-inch rotors use aluminum hats to save weight. The kit was pieced together by Scooby Sport in Europe and is being sold through Rally Performance in America. Our kit was among the first in the country and showed some early teething problems as well as some impressive performance.

0209scc_projwrx03_z Photo 3/14   |   If your rotors look like this, it's time for replacement. We cooked our stock rotors after several hard runs up our local mountain road. Note the brake pad imprint. This is what happens if you stop--even for a second--on hot brakes.

Installation gave us some worries, as we had to remove material from two of the bolts that hold the caliper bracket to the hub. These bolts were a few thousandths of an inch too long, causing possible interference with the rotor under heat expansion. A few minutes with a belt sander fixed the problem. Ken Cole from Rally Performance says this issue has been corrected in the production kits.

More importantly, the brake lines supplied with our kit weren't designed to fit the WRX's stock strut mounts. Our lines were designed for use with Leda struts. Instead of letting the lines flop around in the wheel well where they may get snagged by the tire or suspension, we found a temporary solution with adell clamps and zip ties. Cole promises customers will have a choice between brake lines designed to fit the stock strut housings or custom lines for use with LEDA struts--both braided stainless units from Goodridge. The lines will be available with a vinyl sleeve as further protection against heat or debris at customers' request.

0209scc_projwrx04_z Photo 4/14   |   Project Subaru WRX

Included in the Brembo calipers from Rally Performance are Pagid blue pads, which are known to function over a large heat range. We installed Porterfield R-4S pads in the rear. The R-4S is designed as a high-performance street pad and matches the Pagids well.

The larger AP rotors did interefere with the stock heat shield slightly, but we were able to simply bend it out of the way. We've learned the hard way that removing this shield on a gravel car will quickly lead to rotor full of gravel.

0209_05z+subaru_wrx_sedan+brake_pad Photo 5/14   |   This is what the rotor hat looked like on our AP rotors after the brake pad backing plate contacted it during hard braking. Rally Performance and Scooby Sport have now corrected the problem.

On the road, the new brakes took some getting used to. The brake pedal still has some initial slop but is very firm once you get through that first bit of mush. Pedal effort is surprisingly high which is actually nice when you're red misting.

Our first month with the new brakes was a mix of good and bad. The good times were really good; the Brembo/AP combination's fade resistance and virtual indestructibility regularly overwhelmed us. On several occasions, we heated the rotors to glowing orange but were never able to fade the brakes. In fact, we haven't even bled the system after more than three months under punishing conditions like these. Silkolene fluid is good stuff.

0209_06z+subaru_wrx_sedan+wheel Photo 6/14   |   Sixteen-inch Tecnomagnesio TM Racing wheels from Rally Performance have the caliper clearance to fit over the huge Brembos. The wheels are supplied with center caps, but we prefer the way they look without them.

About three weeks in, however, we began to notice some expensive metal-on-metal sounds once the system was up to temperature. Close inspection revealed interference between the backing plate on the brake pad and the aluminum rotor hat. Apparently, there's a few thousandths of an inch overlap between these two pieces when the whole system has expanded from heat. The interference is just enough to scar the hat and make some awful noises. Brake function under these conditions is inconsistent. The pedal sometimes has slop and is sometimes immediate. Either way, it's disconcerting.

Rally Performance says the problem has been fixed on all the kits leaving the UK and stresses that this was an early run production mistake. Scooby Sport is now removing the material from the rotor hat, which was causing the problem.

In all, we're impressed with these brakes. Their improvement over stock is substantial. Retaining 16-inch wheels has allowed a considerable amount of gravel fun.

0209_07z+subaru_wrx_sedan+front_right Photo 7/14   |   We installed a switch to turn off the ABS in our car after going through this routine too many times. Without a switch, the ABS can be disabled by removing a wheel speed sensor.

Tarmac brake testing
Brimming with short-stop confidence and ready to see what our new brakes could do, we headed out for a little data gathering with our 17-inch Falken Azenis rubber fitted at each corner. During our comparison test in the July issue pitting the project car against the Lancer EVO VII, the WRX put down a two-stop average of 109 ft from 60 mph to zero. We weren't expecting such staggering numbers this time, however, because we were testing on a different surface with less grip.

Before we set out, we installed a switch in the car, which allowed us to turn off the ABS system. This task is a simple matter of interrupting any of the wires going to any of the wheel-speed sensors. We used a switch from Radio Shack and the whole operation took about an hour. Once the ABS is switched off, it won't reactivate until the switch has been put back in the "on" position and the ignition has been cycled.

With the ABS on, Project WRX made three consectutive stops in 118, 117 and 122 ft. However, ABS activation was slow and inconsistent, even when the pedal was crushed with anger.

Switching the ABS off led to some interesting results. With a human controlling the pedal, the car stopped in 120, 117 and 114 ft.--more than a foot shorter, on average, than using the ABS. Why? The answer is fairly simple.

Given the huge grip of the four 225-series Falken Azenis tires at each corner, even the massive Brembos lack the power to lock the tires until the car has slowed to almost a complete stop. This means that even a pedal-crushing monkey could produce relatively short stopping distances by smashing the pedal to the floor. Modulation didn't become a factor until the car had slowed to about 10 mph. More careful attention to caliper piston sizing might produce better results.

Criticism of the system should be withheld until careful consideration is given to several factors. First, there's little hope the stock brakes would match the distances, heat capacity or consistency of the Brembo/AP setup. What's more, less grippy tires would lighten the load on the brake system, making the human factor much more important. It's likely that with less grip at the tarmac, the brakes would have the power to lock the tires at any speed. In this case, ABS will beat a human virtually every time--on the tarmac.

Gravel brake testing
We've theorized that stopping a car in the gravel is a job better suited for the human brain than a modern ABS system. This month, we set out to prove it. Since Project WRX spends lots of time in the gravel, it was only a natural progression to hit the dirt with our radar gun, big brakes and 16-inch wheels with BFGoodrich g-Force KDWS tires to find out. Turns out, we were right--sort of.

We measured stopping distances from 60 mph just as we would on tarmac. We used the ABS initially to establish a baseline. However, Subaru's sensitive ABS system outsmarted itself time and again on the gravel, producing huge variances in stopping distance depending on the roughness of the surface. Over washboard, for example, the distances were much longer than on smooth gravel. Using ABS, stopping distances from 60 mph varied between 208 and 263 ft.

Modulating the brakes was next. With the car at about 65 mph, we applied the brakes and used a threshold braking technique to wrestle the car to a stop, measuring only the 60 to 0 distance. Again, this technique proved remarkably inconsistent as surface changes and the human factor proved difficult to overcome. However, it did produce shorter stopping distances than a mindless, pedal-mashing ABS stop. Using threshold brake modulation, the distances came down to between 173 and 202 ft over three runs.

Given the difficulties with ABS and modulating the brakes, we performed an all-out brake lockup as well. Not surprisingly, with most of the variables taken out of the equation, locking the brakes proved the most consistent way to stop in the gravel. Stopping distances using lockup ranged from 186 to 197 ft. Ultimately, modulating the brakes produced a shorter stopping distance, but with the inconsistency involved, it seems locking the brakes is perhaps more effective. Remember, you can't turn with the wheels locked. That's why manufacturers give you ABS.

What's Next
We're not sure what's next for Project WRX. It seems unlikely we'll get through an entire year in this car without changing the springs and dampers. However, we've got a tall order in this department.

More power is surely on the way in the form of a turbo upgrade. Then we'll have to modify the fuel system. These things never end. See you next time.

0209scc_projwrx08_z Photo 8/14   |   The fuse block is removed with one screw and several plastic tabs

Foglights
True manual control for factory fog lights

We're tired of fog lights that turn off when the high beams come on and we're tired of factory wiring dictated by bureaucrats.

No more. This quick wiring mod allows the fog lights to be switched on anytime the headlight switch is in the "parking" or "on" position.

0209scc_projwrx09_z Photo 9/14   |   With the fuse block removed, relays come out using these tabs.

Begin by removing the dashboard underneath the steering wheel, which comes off with three screws. This exposes the fuse box and relays, which must be removed from their mounts to provide access to the wires in back. The fuse box is held in place with one screw, which is on the top, and several tabs. The relay box is held in place with tabs only (see photo).

With the fuse box removed, splice a 6 to 10-inch piece of wire into the orange wire coming from the parking light power supply on the back of the fuse block. Terminate this wire into the red wire with a green stripe coming from the fog light relay, which is the fourth relay down from the top. Tape off the red and green wire and tuck it out of the way--it was the power supply for the fog lamp relay, which worked only with the headlight low beams, and won't be used.

0209scc_projwrx10_z Photo 10/14   |   Splice into the orange wire coming from the fuse block on the left, which provides power to the parking lights. This spliced wire is then used as the power supply to the fog light relay.

Test to be certain the fog lights work with the high beams and with the parking lights before putting things back together.

0209_11z+subaru_wrx_sedan+front_right Photo 11/14   |   Project Subaru WRX

Yakima bomb-proof bike rack
What can we say about Yakima's Viper bike rack that isn't said in the lead shot?

If you're sick of stuffing your mountain or road bike in the back of your WRX then Yakima's Viper rack is a pretty elegant solution. Its easily adjustable skewer-mount assembly is entirely overbuilt and looks like it could handle a thermo-nuclear assault. The whole rack is designed to be lockable and can handle virtually any of today's single- or dual-piston, disc brake-equipped mountain bikes. It's also extremely easy to remove from the car in a matter of seconds. Did we mention it's indestructible?

0209_12z+subaru_wrx_sedan+right Photo 12/14   |   Clearshield paint protection film can be applied at any qualified dealer. XLNT Tint in Anaheim, CA. handled the installation on our car. Both the custom work and the pre-cut kit were applied in about two hours.

Clearshield
We drive in the dirt, and we do so shamelessly. However, since Project WRX isn't ours and must be returned to Subaru of America after its stay in our stable, we figure taking care of its paint is a smart thing to do. Bekaert Specialty Films makes a product designed to do exactly that--invisibly.

Clearshield is an 8 Mil-thick paint protection film designed for automotive applications. The film is available in pre-cut, application-specific sheets or can be cut and custom fit to nearly any part of the car by a qualified dealer. We used both on Project WRX.

Bekaert supplied its pre-cut kit for the front of the WRX and enough Clearshield in rolls to cut custom patterns for the fenders and rocker panels on our car. XLNT Tint in Anaheim, Calif. handled the installation.

0209_13z+subaru_wrx_sedan+left Photo 13/14   |   Project Subaru WRX

Clearshield is designed to protect paint from impacts with gravel, road salt, sand and insects. Our experience so far agrees with those claims. We can't attest to its effectiveness against road salt, but it seems impervious to nearly everything else. Despite our propensity for gravel driving, the front of the car still takes the biggest pounding and the Clearshield shows it--but only slightly. Impacts with road debris result in small imperfections in what would otherwise be invisible film. But, we'll take that any day over paint chips. The film has been on our car for about six months and goes unnoticed by all but the most observant onlookers.

The pre-cut kit for the WRX retails for about $250 installed and covers the leading edge of the hood, grille surrounds and fronts of the fenders. Expect to shell out about twice that amount for a full custom fitment like ours, which includes nearly every square inch of bodywork on the sides of the car below the lowest body line. Clearshield is removable anytime with no ill effects and comes with a five-year warranty against fading or peeling.

0209scc_projwrx14_z Photo 14/14   |   Progress Technology's 22mm adjustable anti-roll bar turns a conservative WRX into a tail-happy thrill ride. We love it--just be certain you're ready for the change.

Progress Technology anti-roll bar
We don't like compromises. Combine this fact with the WRX's heavily damped, long-travel suspension and we soon realized there's very little need to change it for the kind of driving we do.

Sure, on a racetrack, it's not ideal, with too much dive under braking and substantial body roll at the limit. But, because Project WRX isn't a track car, we really don't care. Project WRX sees most of its hard driving on rough mountain roads or sideways in the gravel, so lowering it isn't an option. We'll probably eventually find a suspension that makes us happy, but we're starting with basic but effective changes.

It doesn't get more basic or effective than a Progress Technology anti-roll bar and putting one in the rear of our car is probably the most cost-effective chassis mod we can make. Progress recently redesigned its rear anti-roll bar for the WRX in an effort to make it more likely to fit with the numerous aftermarket exhausts available for the car. The bar, which now goes over the exhaust instead of under, clears our 3.0-inch Supersprint pipe.

Installation is simple, although you may need a die-grinder or rat-tail file to remove small amounts of material at the stock mounting points. Progress uses the stock anti-roll bar mounts as fastening points for stand-offs which locate the bar about 2 inches from the chassis. Even with the grinding, it only took us about an hour to install the bar using a lift.

With the bar in place, the WRX's character during hard cornering is completely changed. Get out of the throttle aggressively mid-turn and you'd better be ready to catch it because it's coming around. In fact, when set in the most aggressive setting, even the oversteer-hungry SCC staff found it to be a handful. We've also noticed it affects the car differently depending on which tires we have fitted. With the 16-inch BFGoodrich g-Force KDWS rubber, its effect is far more pronounced than with our 17-inch Falken Azenis tires. We love the bar, but its endorsement comes with this word of warning: With the bar on the full stiff setting (innermost adjustment hole) the WRX is no longer a beginner's car. The 22mm bar is three-way adjustable and retails for $249.

Sources

BFGoodrich
877-788-8899
www.bfgoodrichtires.com
A'PEXi
Orange, CA 92868
714-685-5700
http://www.apexi-usa.com
Vishnu Performance
Danville, CA 94506
866-584-7531
http://www.vishnutuning.com
Progress Technology
Anaheim, CA 92806
800-905-6687
http://www.progressauto.com
Porterfield
949-548-4470
www.porterfield-brakes.com
By Dave Coleman
94 Articles

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