While Autotech hyped the VR6's output by installing its own computer chip, stainless steel exhaust, Shrick 260 cams, and K&N Filtercharger air filter, the really trick stuff lies in the gearbox. Installed there is a Quaife torque-biasing differential, which constantly directs more torque to the drive wheel that has the most traction. In front-drive cars like the Jetta, this is particularly critical, since the front wheels also have to do the steering along with most of the braking. The Quaife has proved itself not only on Volkwagens, but on racing Hondas, Acuras, and others as well. Beyond its torque distribution talents, the $1095 Quaife in the Jetta also packed a 3.94:1 ratio gearset (another $495), significantly deeper than the standard 3.39:1 ration.
With 213 claimed horsepower and its delivery ensured, Autotech plants this Jetta to the road with a 25-millimeter hollow front anti-roll bar ($150), a 28-millimeter hollow rear anti-roll bar ($200), a front strut tower bar ($125), a set of Hor Technologie progressive-rate springs ($225 for all four), and $525 worth of Bilstein shocks. That suspension supports Autotech's own front ($290) and rear ($240) drilled and slotted disc brakes and a set of TSW 17x7.5-inch Stealth wheels ($992) wrapped in P215/40ZR17 Toyo Proxes T1 tires (about $700). So how does $6500 worth of upgrades make a Jetta feel? Dang good.
Like all VR6-powered Volkwagens, the sensation is of almost-infinite torque. The Autotech chip moves the rev limiter from the standard 6300 rpm up to 7200 to take advantage of the radical cam profiles. Running into the red on the tachometer can be disconcerting at first, but after a while, the driver will seek that red zone as a badge of honor. Compared to the last VR6 GTI Motor Trend tested (which is significantly lighter than the Jetta sedan), the Autotech car's 0-60 time is 0.7 second better at just 6.5 seconds. And the quarter-mile consumption is just 15.1 seconds at 92.8 mph. Almost better than the performance is the stunning howl the car now makes; no one will mistake this for a pokey four-cylinder grocery-getter.
The differential shows itself on the slalom where there's virtually no wheelspin. The effect may be even greater on the skidpad where the sustained attitude of the car means one front tire has far more traction than the other. The 0.88g skidpad orbit and 66.7-mph slalom time both bear that out.
With the car so low the ride is obviously compromised, but it's tolerable. And with the rest of the car so engaging, almost unnoticeable.