For VW fanatics of years past, the GTI was the pinnacle of Volkswagen performance and technology. However, with mainstream integration of VWs product, the original vision of the GTI has been lost, turning the GTI into little more than a trim package. Granted, VW does intend to remedy this in upcoming model years and reorient the focus of the GTI towards the performance side, but that still leaves owners of the current generation of the GTI wanting something a little sportier. Enter Autotech.
Autotech has been tuning watercooled Volkswagens (And only Volkswagens.MAX) since deep into the last millennium and has developed a list of products for the GTI longer than a roll of toilet paper. The companys Sport Tuning philosophy has existed since its 1983 inception, and simply stated is to improve all parameters of the performance envelope of a vehicle. When we found out that Autotech was going to sport-tune the hell out of a 2000 1.8T GTI, we began a thumb wrestling competition to see who would be the lucky staffer that would get to spend a week in beautiful San Juan Capistrano, California, at Autotechs facility. The added bonus to cataloging the buildup was that the staffer would be able to drive this car for that week and play with it after each round of modifications. The down side, however, was that the car had to be given back to its owner after that week was up.
First up on the list of mods to be performed was adding power to the decidedly anemic 1.8L turbocharged engine. The beauty of this little dynamo is that it is extremely under-tuned from the factory, and getting a lot more power requires little more than reprogramming the engine-management software and alleviating some of the back pressure that the turbo has to deal with. With a reported 150 flywheel horsepower available, we began our first round at Magnaflow Performance Exhausts Tech Center in Rancho Santa Margarita. At the Tech Center, we established a baseline dyno plot to calculate how much additional power Autotech was able to produce.
Wheel horsepower, transferred to the ground through the stock wheels and tires, rang in at 139.2. Now, depending on whether you subscribe to the 12.5-percent drivetrain loss convention or prefer to determine the drivetrain loss by interpolating it from the factory-claimed flywheel horsepower and the actual dyno numbers makes all the difference. Therefore, were going to give you both. Performing the necessary math, we determine that the actual flywheel horsepower is 159.1 by using 12.5 percent as our conversion factor. If we compute the drivetrain loss using VWs numbers and our own, we determine it to be 7.2 percent. Torque, however, is another story.
Dynojet dynamometers are great for determining horsepower and torque gains but may not provide you with absolute output numbers. What this means is that while our gains are real and accurate, we may not be putting out the exact numbers that the dyno sheet reads. This is especially apparent in the torque figures we obtained.
For the 2001 model year, VW rates the 1.8T in the GTI at 150 hp and 155 lb-ft. This, however, is a model year 2000 car, and Volkswagen introduced the 1.8T into the GTI halfway through that year. In the 2000 press kit provided by VW, the only transversely mounted 1.8T was available in the Beetle and made 150 hp and 162 lb-ft. What this means is one of three things: the dyno numbers over-estimate the output at the wheels; VW underrates the torque numbers for the 1.8T in the GTI severely; or the torque numbers are still underrated but are based on the Beetles 1.8T rather than that in the current GTI.
Whatever the case, gains are what we are interested in, and our baseline torque number was established at 160.3 lb-ft. After the first round of modifications, which included the replacement of the stock air filter with a K&N direct- replacement filter and the addition of Autotechs Q-Chip, horsepower jumped 22 ponies to 161.2 hp, and torque went up by 28.3 lb-ft to 188.6. With the addition of Autotechs exhaust, it was immediately apparent that the chip is tuned to work with the 2.5-inch diameter piping of Autotechs exhaust. Where the chip with the OE exhaust had a drop in horsepower at about 5,100 rpms, the horsepower continues to build with Autotechs exhaust. At 5,380 rpms there is a 35 hp gain with Autotechs exhaust in place, but peak horsepower builds to 180.1 hp at 5,180 rpms. Torque also jumped up to 206.5 lb-ft with the 2.5-inch exhaust, relieving a lot of back pressure.
Once all the components were installed, it was time for a test drive. The turbo characteristics are amplified with the addition of the parts, but it is manageable if you can deal with the lag and the rush of power that occurs once the turbo has spooled at about 3,000 rpms. At cruising speeds on the local freeways (About 65 to 75 mph.MAX), downshifting to pass was about as pointless as asking George Bush, Jr. the meaning of the word hypocrite. The car accelerates like a rocket, but there was one problem. The GTIs stock suspension wasnt up to the extra power and left the driver feeling extremely unsure about high-speed canyon runs and highway jaunts. That, however, was taken care the following day with the suspension mods Autotech performed. Youre going to have to wait until next month to get the inside look at Autotechs reworking of the GTIs suspension, but take a look at the installation of this months parts and dyno plots to get an idea of what you can expect from Autotech. See you next month for more Sport Tuning.