Taking Stock Dec 4, 2009
When we decided it was time for another Subaru project, we considered a few options. A Forester XT, a 2004 STi and earlier Imprezas were considered, but in the end we decided to use an early WRX. This is the car that really brought Subaru to the fore as a performance-oriented manufacturer in the North American market. Plus, it enjoys as much aftermarket support as anyone could hope for. No matter what our end goal would be, the 2.0-liter terror was sure to be capable of meeting the challenge.
Once we knew what we wanted, we began our search. Sometimes it can be hard to find the right car; we spent a lot of time sifting through high-mileage vehicles with "noisy" engines and salvage-titled My First Tuner turds before we found what we were looking for. We liked what we saw in a simple craigslist ad from nearby Jacksonville, Florida. This example had low mileage for its age--just over 63,000 miles on the odometer--and had been driven since new by a college student. It appeared to have received capable maintenance and regular oil changes throughout that time, and it showed no signs of previous modification other than a set of hideous aftermarket Altezza-style taillights. (Thankfully, the previous owner kept the originals, so it was a 5-minute job to swap back.)
We did notice some evidence of a mild fender bender, and the owner was straightforward when asked about it. The damage had been very slight, but it required one of the headlights to be replaced. Unfortunately, the opposite light had become slightly fogged over. While the discoloration is slight, the difference between the two lights is pretty noticeable. We'll be trying one of the many headlight restoration kits out there to see if we can bring our foggy light back to life.
The car was sold with the original 16-inch wheels, but the tires were absolutely shot. Normally we would have simply replaced the tires, but since this set of 17-inch Rotas with Nitto NT05s was available from our last Subaru project, we just bolted them up for the time being. Inspecting the stock units also has us wondering if the car could benefit from an alignment, as the wear is primarily on the innermost edge of the tires. The camber looks to be within spec, so we'll check the toe settings to ensure that we'll get full use of the Nittos.
WRX Goes to Work May 28, 2010
Now that we've owned our WRX project car for a few months, we're ready to dive into the improvement phase. First we needed to generate some baseline performance data for the car. It's nice to know where we stand in terms of performance, and the process would reveal any shortcomings.
We started our test day by taking our WRX to an as-purchased configuration, right down to the crappy Negotiator tires on stock WRX alloys that had been installed by the previous owner. "Negotiator" was the right name: Every turn was a negotiation as the tires howled for mercy and resisted directional changes. Still, the beauty of all-wheel drive allowed us to navigate the course safely and consistently enough to generate a baseline.
We can't wait to start turning wrenches on our project, so watch this space as we begin to add some grunt and grip to an already capable car.
Piping-Hot Performance Jun 21, 2010
Exhaust upgrades are a great starting point for any turbocharged car--especially an early WRX model like ours. Moore Performance & Race Parts sent us one of their 3-inch stainless exhaust systems for testing, so why wouldn't we bolt it on and try it out?
Before installation, we ran some baseline acceleration tests to measure the new system's effectiveness. Using a calibrated, professional accelerometer, we tested the car's acceleration from 20 to 50 mph. This method removes variables such as shifting and traction, making it a more accurate measurement of engine power than a zero-to-60 test.
Like most factory exhaust systems, the stock pieces were heavy and didn't promote the easy breathing flow characteristics that allow for more power. This was especially true of the factory downpipe, where exhaust gasses are routed from the turbocharger itself. The Moore Performance piece uses a separate 2-inch tube for the turbocharger wastegate, which they say promotes better exhaust flow and prevents turbulence around the wastegate itself. This, in turn, should provide better boost control.
A less common modification--but one of particular importance for owners of early WRX models like ours--is replacing the factory uppipe. This seemingly simple piece connects the exhaust manifold to the turbine inlet, where the heat and pressure of the exhaust spin the turbine itself. Early model WRXs are equipped with a small pre-catalyst in the uppipe to help with cold-start emissions readings.
We've studied catalysts and their effect on performance, and we don't normally condone their removal. Unfortunately, when these units eventually fail, they have been known to send debris from the failing catalyst structure through the exhaust stream and directly into the very hot, very fast-spinning turbine. This will turn your high-precision turbocharger into a nifty paperweight.
An ounce of prevention beats a pound of cure, so we chose to replace the factory uppipe. As a bonus, the higher flow heat and gas flow are reported to improve the rate at which the turbocharger spools up to create boost. Faster spool means a faster car, so how could we complain?
Installing the parts was more time-consuming than difficult, but it pays to take your time. Getting some buddies together on a weekend can make short work of the process. The Moore Performance parts were a snap to install, as most of the system uses a slip-fit, banded-clamp construction that allows a great deal of control over the physical location of the exhaust. This prevents any rattling or unwanted chassis contact.
The Moore Performance exhaust is constructed completely from 304 stainless steel and features big, strong flanges to ensure a long service life. Seriously, the stuff screams quality. In an age where consumers can order an exhaust system that's sold as "stainless steel" but feels soda-can flimsy, it's nice to have a product that feels as well made and durable as these.
In the end, though, we made this upgrade in search of more power, so once installation was complete we eagerly measured our gains. Our next round of acceleration tests revealed that we were indeed making gains; the run from 20 to 50 took only 4.03 seconds, an improvement of nearly a full second. To put it in perspective, that's nearly 20 percent quicker with no other modifications. We told you that turbocharged cars respond well to an open exhaust, right?
Subaru's boxer engines have a polarizing effect on enthusiasts; those who like the rumble of a flat-four seem to like them at any volume, while some folks simply don't care for the noise. If you're among those who enjoy a snarly, whistling beast—you're in luck. Our WRX sounds downright racy, especially under load at wide-open throttle. We're looking for a nice, long tunnel in the area for a late-night session of the internal combustion opera.
Of course, this just opens the Pandora's box of modifications that much wider. We're expecting the Subaru ECU to wise up to our antics any moment now and illumintate the check engine light thanks to wildly altered flow characteristics and a now-missing temperature sensor from the uppipe's pre-catalyst.
Again, the aftermarket shall provide. Stay tuned as we investigate the expanding frontier of open source tuning tools. We've also got some driveline maintenance to do, so look for freshened hubs, bearings and brakes in future updates.
We're always looking for your feedback, so if there's something you'd like to see us try or evaluate, post a comment below or drop us an e-mail and tell us all about it.
Studly Subaru Jun 9, 2011
Our Subaru WRX has been working really well as a daily driver, but we can't have a thoroughbred like this living a life of ease for too long. After reflecting on a goal for our all-wheel wonder, we decided to keep it simple and enjoy using it as a track tool. Sure, it's not a grand goal, but it's one of the things a Subaru is great at. Grip at all four corners and benign handling characteristics also makes our Subaru a fantastic learning platform.
Despite the track-ready performance of the early-model WRX, there are some stock components that aren't quite up to snuff. Case in point—lots of carry-over parts from lesser Impreza models are easily overwhelmed when faced with the relatively high horsepower and g-loads of a WRX on track. After our last session at the Ocala Grand Prix, we noticed a stripped wheel stud at the front of our car. Luckily, we were able to nurse the Subaru home with four lug nuts and some good karma.
It only makes sense to replace the wheel studs as a set, and since we were doing one side we might as well do the other. Disassembling the car down to the point where the hub can be removed and the studs pressed out is a pain, so we went with a stronger, more durable replacement stud from ARP. These are the same studs used on ridiculously powerful race cars around the world and should serve us well through thousands of wheel changes, torque applications and heat cycles. Barring genuine abuse, we should never have to worry about them again.
We considered changing the wheel hubs as well, since they're a common failure point on track-driven Subarus. It's a common enough problem that Subaru beefed up the hubs and bearings on the STI models after 2005, and the aftermarket offers many one-stop solutions for racers and track day enthusiasts. The only problem: They're bloody expensive at just over $500 bucks for a pair of heavy-duty hubs for just the front wheels. Despite the damaged wheel studs, our hubs and bearings looked and felt fine. So, we decided to hold off on upgrades here until we really need them. (They'll be on our list for Santa as well.)
With the new studs in place, we're ready to head back to the track. For now, we're enjoying the car both on and off the track—just as the sales brochures and video games promised—but there's a lot of room for improvement.