Project Subaru WRX V.08 - Sport Compact Car Magazine

The show car is dead. SEMA has come and gone. Now it's time to get Project WRX V.08 sorted out. What we have so far: lightweight forged Prodrive wheels, grippy Yokohama tires, TEIN's Super Street suspension, AP Racing brakes and some bolt-on power. Plus, shortly after its appearance at SEMA '07, the fancy stereo and steering wheel were dumped for original OEM integrated parts. But in the rush, we never got to test or baseline the car, except on the dyno. So we had to see where we sat and find out if we were close to big-brother STI territory.

Just as we were going to rectify matters, Subaru released the 2008 Impreza WRX STI and we managed to steal one for a week-long evaluation. Our first impression was (as with the WRX and base Impreza) that, while still a fast machine, the STI had become softer and more docile. Even with all the fancy traction doo-hickies and additional variable exhaust cam, the '08 STI felt slower than versions of old. To settle the matter, we dug up a bone stock 2007 STI on semi-fresh OEM tires and pitched it in a three-way battle against the 2008 STI on (slightly abused) stock tires and our Project WRX V.08.

Horsepower
First things first: see how much power and torque each car makes. Project WRX V.08's massive and instantaneous low-end torque makes it a blessing to drive on the street but, on the rare track session, the turbo seems to lose its breath as the engine approaches the rev limit. Up to 3000rpm, our WRX makes more twist than either STI and holds it for another 2000rpm, up to the point where the '07 STI finally finds peak torque.

Although low-end grunt isn't its forte, the previous-generation STI is another beast altogether, with torque and power that hits like a hammer once the turbo spools. From then on, it's a mad race to catch the next gear in time and make sure there's enough clear space in front. It's as muscle-car as an import gets.

The same or more is expected from the '08 STI. More top-end power and a faster turbo spool (on account of the variable exhaust cam) should bring this car closer to a true restrictor-plate, anti-lag rally beast. Not the case. Even with a 30lb-ft torque advantage chiming in earlier, the car still seems slower, either because of gearing or the fickle boost-regulating e-throttle. Stoplight acceleration feels restricted, as does top end. While K&N Engineering's all-wheel drive Dynojet shows an almost 10 wheel-hp and 30lb-ft torque gain from '07 to '08, the car doesn't hit like its rocket sled predecessor.

The Quarter-Mile
With less power, fewer gears, inferior aero and no Driver Controlled Center Differential (DCCD), we expected Project WRX V.08 to be well behind the two STIs in the quarter-mile sprint. A minor loss in our book, since handling matters more to us. The big surprise is how much faster the old STI is compared to the new car, which has larger tires (245-width for '08 versus 225-width for '07) and fancier aero.

We re-tested the 2008 STI several times before we backed up two runs that brought the difference down to 0.4 seconds and six mph in trap speed, even though the 60-foot and zero-to-60mph stats were nearly the same. The 2008 STI lost the race on the top end.

After several punishing passes, we also figured out that, while a good ET and trap speed usually comes from setting the DCCD into a logical full-lock position, launching in auto mode gives more consistent, faster and (most importantly) driveline-saving launches.

Project WRX V.08 came in 0.4 seconds and 2mph behind the '08 STI. Although its launches weren't as fast as either STI, our WRX made up some of the gap to the '08 on the top end. But it still ran the quarter almost a second slower than the stock '07.

Braking
While not a comprehensive test, repeated 80mph-to-zero stops heat up most systems to the verge of fading. Stopping distances are basically a matter of weight, grip and, in some cases, brake balance.

Even though the 2008 STI uses wider 245 tires, Project WRX V.08 still has the advantage with 225 super-sticky Yokohama Advan Neova tires that outperform the already amazing OEM Bridgestone RE070s on the STIs. Distances for all three dropped into the 200-foot ballpark, on par with an R-compound-equipped Lotus Elise Sport.

Figure eight
Complaints and speculation on the relative softness and 'disconnectedness' of the '08 STI were put to the test through our figure eight test. This is made up of two 200-foot diameter circles set 500 feet apart (from center to center)-large enough to test turn-in, lateral grip (in both directions), acceleration, braking, transitional response and the overall balance of any car. It's consistent, simple and easy to read.

By the advertised specs, the '08 STI should have the clear advantage with more tire, horsepower and a smarter vehicle dynamics computer. By the seats of our pants, it should be the slowest. While none did so well as to break into the 24-second Ferrari supercar range, the 0.2-second spread was enough to retain trust in our well-calibrated butts.

While it looks like we're splitting hairs, based on the speed and lateral-g traces of each car's hot lap, the '08 STI shows its advantage with acceleration out of turns and with higher cornering speeds. But its softness comes into play with earlier, harder jabs at the brakes, earlier turn-in, more time for the chassis to take a set on account of the softer suspension and a delayed steering and throttle response used to balance the car when completely loaded in the turns. The '07 didn't post remarkable peak values, but is faster, edgier, and quicker to set and balance. It's still the driver's car with the least understeer, best gearing and power delivery.

The big upset comes from Project WRX V.08. While we'd like to say its Airtab vortex generators helped, our WRX beat its big brothers by showing that smooth is fast. It had less peak speed, slower acceleration and the dumbest of all the all-wheel-drive systems, but the stickier tires, wider gears (which could be stretched all the way to the braking zone) and low-end torque (to launch it out of corners) made all the difference. Feather-light steering feel with the TEIN suspension also changed the WRX's characteristics by giving it an instant set with minimal roll.

There's still more room for improvement with Project WRX V.08. We tested it with the TEIN suspension still set at SEMA show-car height. With more wheel travel, a higher spring rate and more front camber, we should be able to eliminate corner-exit understeer and make the car even easier to rotate.

Rumination
Ultimately, differences in performance boil down to traction, power and driving dynamics. Each car has its own character. It's hard to blame Subaru for making a more mass-market-friendly car, but the newest STI leaves the edge off what was once an exclusive heritage. Still, it's made of the right stuff, just massively detuned from the factory. With less environmentally friendly ECU tuning, a more uncompromising suspension and bigger exhaust pipes, the '08 STI could definitely have the upper hand, even against a tuned 2007 STI.

With an idea of Project WRX V.08's strengths and weaknesses, we'll reformulate a plan of attack. We'll look at some more bolt-on power parts, proper ECU tuning, an updated suspension and possibly some way to stuff in more tire.

Previous Installments
January 2008
Part 1: Our new and, hopefully, long-term project car

March 2008
Part 2: Back in black, for the third time