Over the years, the objective of getting the most performance from the smallest displacement has been foremost in the minds of enthusiasts. The reasons are simple. Weight, ultimately, is the enemy of speed, so you want a small lightweight engine to power your vehicle. However, more power usually means more engine.
Forced induction is the answer to the question most of the time. It's a relatively easy, cheap and reliable method of boosting power without adding a lot of weight to an engine. The idea of cramming more air into an engine than atmospheric pressure and cylinder vacuum allow isn't new, of course. And modern construction techniques, computerized machining equipment and electronic fuel injection have made forced induction, if not commonplace, then at least reliable and not unexpected.
Of course, Honda has taken a different route to high-performance small engines. Rather than shove more air in with a pump, it sucks more air in with amazing volumetric efficiency. So, forcing more air into one of those engines should yield excellent results, right?
Vortech has been in the forced induction market for more than a decade, establishing itself as a leader in centrifugal supercharger technology. There are as many superchargers out there as you could imagine, from Archimedes-inspired screws to the twisted lobes of a Roots-type blower. A centrifugal supercharger is essentially the compressor side of a turbo, but instead of using exhaust gas pressure to spin, it's connected through a reduction gearset to the crank. The upshot is you get the joys of forced induction, but with a much neater, easier-to-install package.
You read about Vortech's Civic Si supercharger kit a few months ago (HT, Winter '02). But this is the first look at a similar kit for the Integra GS-R, a vastly more popular car.
The principle is roughly the same for both systems, not surprising considering the engines and chassis are much the same. A four-rib belt drives a shaft connected to the supercharger itself. The shaft is constructed of ultra-high strength chrome-moly steel, and is housed inside its own tube. The supercharger produces approximately 7 psi of boost before the bypass valve on the intake tract kicks in. Let's cut to the chase: During our testing at the International Performance Group's Tech Center, the Vortech-supercharged Integra belted out a best run of 245 hp at 8000 rpm at the wheels, about a 100-hp improvement compared with stock GS-Rs we've tested. Torque was equally impressive, with the Integra twisting 161 lb-ft at the same engine speed.
Centrifugal superchargers are generally used to enhance the high-end output of an engine, and this is dramatically displayed in how the Vortech V5-G trim unit works on the Integra. It basically moves the power curve, if you will, bumping it up along the entire rev range. Sure, the engine's still peaky, but it also develops more power (a lot more) at that high end, and it develops more torque at the bottom end, even if the power curve is roughly the same.
Driving the Vortech supercharged Integra is not a mind-blowing experience, but it is an immensely satisfying one. The car screams to its redline, the familiar B18C howl replaced by the mechanical whine of the supercharger itself. At part throttle, the bypass valve bleeds excess boost to the air, making the impeller of the 'charger as distinctly audible as a taxiing Lear jet. On the freeway, top-gear acceleration is sprightlier, but to beat that Mustang Cobra in the next lane, you'd better downshift a gear or two.
Part of the beauty of the system is in its simplicity. It really is a bolt-on unit. The kit comes complete, with a Walboro in-tank fuel pump, 310cc injectors and Vortech's FMU boost-dependent fuel pressure regulator. It also includes all the installation hardware, such as the O.E.-style cast brackets, billet-mounting plate system, and all the belts, hoses, clamps and zip ties to make the kit work. The engine has been further modified with an A'pexi N1 header and cat-back exhaust system. But that's about it.
The rest of the drivetrain has also been modified to make the most of the power. An ACT clutch and pressure plate make sure the extra power doesn't disappear into funny smells and smoke, and a KAAZ limited-slip differential puts power to the ground even under the hardest of cornering conditions.
Suspension modifications are also quite extensive. Pretty much the entire Progress Group Integra selection is under the wheelwells. Coil-over shocks are on all four corners, along with a camber adjustment kit and anti-roll bars on the front and rear. The suspension gripped the ground very well, although ultimate at-the-limit handling was limited, thanks to the 205/40ZR-17 Toyo FZ4 tires. For better handling, better rubber is definitely needed. The front end was quite twitchy, and the car was clearly set up for smooth roads. Turn in was superb, however, and it seems to us as though someone needs to take better advantage of the camber kit to dial in the last nth of handling from the chassis. The brakes were complaint-free, though. The Integra stopped time and again without drama during our photo shoot; the twin-piston calipers gripped big 13-inch Baer discs, inspiring nothing but confidence.
Inside the Integra, it's all business. An Autometer instrument cluster bezel gauge housing supplements the stock cluster with boost and oil pressure gauges, essential for pressurized engines. An Autopower bolt-in roll cage has also been added. But that's about it for interior modifications, and that's all that is needed. The stock seats are among the best in autodom, gripping the driver vice-like even in hard corners. The steering wheel and shifter both show the shiny wear of well-used leather, but they are still comfortable and fun to grip.
Outside, the modifications are also relatively minor. Look past the graphic treatment, and you'll find a body that is largely stock. The tires are wrapped around 17-inch Racing Hart D6000 wheels, and the stock hood has been replaced with a lighter carbon-fiber unit from Fiber Images. If you were to remove the vinyl, you'd be hard pressed to tell the Vortech Integra from virtually any other red GS-R on Southern California roads.
That would be a mistake, of course. Even with a heavy (and we do mean heavy) speaker box under the hatch acting as an anchor, the GS-R still managed a 14.9 quarter-mile time. Throw in the excessive wheelspin at launch thanks to the mid-level tires, and you'd probably shave a good 4 or 5 tenths.
As a test mule, however, Vortech's Integra has seen plenty of duty, with over 80,000 miles on the odometer. It's still going strong, though, a testament to the unit's reliability. Who says there's no replacement for displacement?
|Type:||Inline four, aluminum block and head|
|External Mods:||Vortech V5-G trim supercharger kit (includes Vortech FMU, 310 cc injectors, Walboro in-tank fuel pump), A'pexi N1 header and cat-back exhaust system|
|Horsepower:||245 @ 8000 rpm|
|Torque:||161 @ 8000 rpm|
|Layout:||Front engine, front-wheel drive|
|Drivetrain Mods:||ACT clutch and pressure plate, KAAZ limited-slip differential|
|Front:||Progress coil overs, anti-roll bar, camber adjustment kit|
|Rear:||Progress coil-overs, anti-roll bar|
|Front:||Baer 13-inch disks, two-piston calipers|
|Wheels:||Front/rear: 17x7-inch Racing Hart D6000|
|Tires:||Front/rear: 205/40ZR-17 Toyo FZ4|
|Acceleration (0-60):||6.8 sec.|
|Quarter Mile:||14.9 @ 96.8 mph|