The first generation TDI was one of the first cars in VW’s North American line-up to be able to make substantial gains from what was then known as “chip tuning.” The chip was physically removed from the ECU and replaced with another which contained more powerful programming. Gains of 25 hp and 50 lb-ft were typical for TDIs (much less for normally-aspirated engines). Later, the 1.8T was able to gain ~35 hp and 70 lb-ft. The subsequent 2.0T gained ~45 hp and 94 lb-ft. These are increases in peak numbers; gains in the middle of the power band could be even greater. Incidentally, all of these ever-increasing gains were being had by engines that were more powerful than their predecessors. This brings me to the Mk7 GTI, the chassis for VW’s most potent North American four-cylinder engine (as of this writing and aside from the Golf R). It starts with a reportedly under-rated 220 hp and 258 lb-ft. Dynamometer testing by tuners and enthusiasts indicates that the actual output is closer to 235 hp and 270 lb-ft, figures which rival that of tuned engines of earlier generations and already beats my bought-back Stage 2 Jetta TDI. A tune alone transforms the GTI into a different car! APR was having a sale and I found a hole in my work schedule that allowed me to visit a tuner during the week. I decided to take the plunge…
I had my eye on APR for a LONG time although I used other tuners for my TDIs. APR is the only company I considered seriously when it was time to amp-up a 2.0T. I considered two APR dealers: 1) Priority Volkswagen, where I bought the car; and 2) Euro Pros, a local VW/Audi repair shop. A part of me wanted to work through the VW dealer, but their limited hours were a major turn-off. They tune only on weekdays at 10am and 3pm (not to be confused with “from 10am to 3pm”). They’re 80 miles away and I didn’t want to take extra time off from work. Euro Pros also only tunes during the week, but I can visit them any time throughout the day. Therefore, I opted to arrive at their door step at 7:30am, the moment they opened. I was seen right away.
There was a time when an ECU had to be removed from the car to complete a tune. As shown above, the early ECUs required replacement of the “chip.” Later, the chip could be removed, flashed, then reinstalled. Eventually, the ECU could be “bench-flashed” without removing the chip (see photo). These days, most tuners are able to flash the ECU through the OBD2 port, which is very convenient. Watching the work is fairly anti-climatic. The only reason to open the hood is to connect a battery charger so that the ECU has optimal voltage during the long flash process. I snapped a few photos, but there’s really nothing that jumps out and says, “This is how my car was tuned.” That doesn’t make the results any less dramatic.
I was accustomed to being quite pleased with a 30-hp bump in power from my TDIs. APR’s basic “Stage 1” tune bumps the Mk7 GTI’s already-healthy peak output by 81 hp and 111 lb-ft, for a total of 316 hp and 381 lb-ft, even with a factory air filter and exhaust system. That kind of power simply eclipses anything I’ve ever been able to get from a TDI with similar costs. There was a time when I believed that a TDI could be made nearly as fast or powerful as a GTI. However, this “Gen 3” 2.0T has raised the bar to the point of being completely untouchable by a TDI. Believe it or not, improved fuel economy can also be had with a little self-control… OKAY… A LOT of self-control! 😉
I was on my way after about an hour. My plan was to drive the car gently until it was completely warmed up (coolant and oil temperatures stable). Even with easy driving, I could feel an immediate difference in how the accelerator felt. I had forgotten about how much more responsive a car is after a tune. My first acceleration test was on a freeway entrance ramp. WOW! I did a few more pulls, thinking I wouldn’t drive more than ten-over the speed limit, only to quickly find myself at 80 mph. First gear is essentially worthless as the tires just scald, even with traction control enabled. Second gear is a little better… the wheels still spin, but not as bad. Third gear is where jail time is had! 😉
I tuned the car at 17,464 miles. Naturally, I’m a little concerned about the longevity of my stock clutch since I’ve just added 111 lb-ft to the mix. I had planned to budget for a clutch, THEN tune the car. But the timing of the sale and my schedule was good enough to make a move. Since I’m not an aggressive driver, I’m hopeful that the stock clutch will last a while and that I will be able to upgrade it before it fails. I think my driving will remain relatively unchanged except for a few on-ramp blasts and the occasional authoritative pass. 😉 If I’m wrong, then I may need some bail money and a good attorney! Fuel efficiency testing is forthcoming.
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