Volkswagen Jetta GLI - Chipping Away at the 2.0T - eurotuner Magazine

Part 3

By Alex Rogan

Photography by Dan Mermelstein

In our never ending quest to make you the most informed readership on the Euro scene, we've lined up yet another combination of parts to test on VW's 2.0T FSI engine. After sampling products from GIAC, Techtonics and Evolution Motorsport on our in-house Project Dub GLI, we followed it up with a full APR exhaust, chip and intake upgrade on Project GTI, which belongs to our East Coast photographer.

For our third test, we heard Vivid Racing in Chandler, AZ had a Mk5 GLI lined up for a Revo Technik ECU upgrade and GHL Motorsports exhaust. Owner Ryan Capp was kind enough to let us document the process on his '06 example, as well as provide some perspective on the "real world" impressions once everything was completed.

Baseline

Clark Turner, who handles Vivid Racing's dyno tuning and ECU upgrades, began the process with some baseline power numbers before any modifications took place. Since Vivid is located in Arizona where temperatures soar well into triple digits, robbing engines of power, the tests were performed at 9am on separate days to ensure similar conditions for consistent results.

After getting the car on the Mustang AWD500 dynamometer, the 2.0T GLI (a six-speed manual) put down a solid 176whp and 210wtq, running 91 octane pump gas.

Comparing this to our other results, the power is almost spot-on Project Dub (177whp) running the same gas, but a bit lower than our Project GTI (189whp) using 93 octane. It's important to remember that weather conditions, the type of dynos used and the fuel can make a big difference, so don't just pay attention to the peak numbers from car to car, but the gains made between modifications on the individual cars. The wheel torque number of 210 lb/ft was close to what we had seen on the other 2.0Ts, so we were eager to see what improvements would register once Vivid bolted on the GHL exhaust.

Exhaust

GHL Motorsports had just completed its new 3" turbo-back stainless steel exhaust, and with speculation about what size is best for the 2.0T (and whether or not an exhaust alone can make power), it was decided to do the exhaust install with the stock ECU to see what would happens.

The GHL Motorsports system is a high quality item, constructed from polished stainless steel and TIG welded for durability. The restrictive stock downpipe is replaced with a 3" monster, and both of the stock catalytic converters are ditched in favor of a single high-flow item. This is the same patented, high-flow cat GHL used on some of its naturally aspirated Porsche headers, so it has good credentials. A single resonator helps tame the sound, while the GHL muffler fits snugly under the car. Dual 3" rolled tips finish off the system, hinting at the potential under the hood.

As we've found on other Mk5s, exhaust install is fairly straightforward and takes only a few hours. Pat Barch from Vivid was on the job, so we kicked back while the hard work was completed. After the stock system was removed in two separate sections, the new exhaust was maneuvered into position. No problems were encountered during the install and it wasn't long before the car was on the ground with an appealing snarl from the tail pipes.

The next morning Clark had the car back on the dyno and we awaited the results from the first pull of the day. Much to our surprise there were some substantial gains from "just an exhaust." Peak horsepower went from 176 to 180whp, but more impressively the GLI picked up 24 lb/ft of torque at the wheels, which is a useful amount on the road.

Additionally, if you study the dyno charts you'll see the overall horsepower and torque were substantially improved under 5000rpm. Ryan was pleased with the results and eager to get the ECU updated.

Revo chip upgrade

The Revo Technik chip upgrade is similar to the APR and GIAC examples previously tested in that it's a simple software upload through the OBD port. Since Ryan's GLI already had the GHL system, Vivid installed Revo's stage 2 software because it's designed to work with an upgraded exhaust. Installation was a painless process that took around 20 minutes, and Clark had the car strapped back on the dyno in no time. Revo doesn't specify program changes, but it involves increased boost plus optimized fuel and timing settings. Although not available at the time, Revo's optional SPS program switching will soon be available, allowing you to switch between stock and 91/93 octane programs, plus having an anti-theft feature. In addition, the "Select Plus" SPS programming will allow the end user to make specific changes to boost, fuel and timing maps to compliment future engine mods.

The Revo upgrade is encrypted and is invisible to the VAG scan tools to ensure minimal hassles during dealership service.

Final results

On the dyno the 2.0T picked up an additional 20whp and 28 lb/ft from the new software, with strong gains as high as 6000rpm. Once again, looking at the peak numbers doesn't show the whole picture since the GLI gained substantial mid-range power and torque.

Compared to the stock numbers, Ryan's GLI gained 34whp and 52 lb/ft of torque with the GHL exhaust and the Revo performance software. So the final numbers for Ryan's GLI are 210whp and 262 lb/ft.

It's interesting to compare these results to our own GLI, Project Dub. It started with similar power and finished the day with 206whp and 248wtq. Project GTI recorded peak numbers of 212whp and 260wtq on better fuel. However, both of these cars also had intakes fitted. So it looks as if the Revo/GHL combination scores the best improvement, and it gives more ammunition to the debate over whether a 3" exhaust is better than a 2.5".Of course, all of this wouldn't mean anything if it didn't perform better on the street, so we got some driving impressions from the eager owner.

On the street

Initial impressions were very good, with the added power making acceleration more impressive, and the improved throttle response was icing on the cake. As we saw it, the top-end power is nice but the substantial torque gains are what transformed the driving experience.

Ryan found that heat soak has become more of an issue during aggressive driving on hot Arizona afternoons. This can be attributed to environmental factors, but a performance chip and hard driving can quickly overwhelm the stock intercooler.

Unlike our Mk5 GTI, which saw a slight increase in MPG when running "off boost", Ryan noted that overall gas mileage has gone down slightly after the upgrades, averaging 24mpg on the highway. However, a new driving style and environmental factors may contribute to the drop, so bear that in mind. In the end, these results compare favorably with the other upgrades we've tested on the 2.0T. As we previously mentioned, the intake system is completely stock on Ryan's GLI, right down to the OEM filter. So it looks like the owners of the 2.0T models have several winning combinations to choose from, but we aren't done yet. We're hoping to have a larger turbo and upgraded fuel system in one of these Mk5s soon, and you can be sure to read the results here.

Contact

Vivid Racing (480/966-3040, vividracing.com)

GHL Motorsports (877/930-0911, ghlmotorsports.com)

Revo Technik (866/632-4060, revotechnik.com)

Product Data

GHL Motorsports 3" turbo-back Jetta GLI 2.0T exhaust - $1099

Revo Technik 2.0T ECU upgrade - $499 Stage 1, $549 Stage 2