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From YourSITE.com Technical Features During the very first drive of our A4 Avant project car, it was quickly apparent that the newer and heavier A4 platform combined with the 1.8T engine in stock form left a bit to be desired. Acclimated as we are to quicker cars, the A4’s oomph factor felt downright average and we found ourselves wringing it out to get around the errant Accord or Camry on the highway. Pushing the A4 for all it had, average commutermobiles on the Washington Beltway were proving tough prey; not a normal trait for cars in our fleet.
Their next approach was to replace the injectors, and the solution worked. However, this application is rather expensive, forcing APR to offer two package options. Stage I uses the original injectors and provides 200hp and 231 ft. lbs., while Stage I Plus incorporates the new injectors, netting claimed power levels of 215 hp and 250 ft. lbs. of torque. Given the A4’s additional weight and the quattro system’s additional drivetrain loss, we opted for the more expensive Stage I Plus. One selling point about the APR ECU is that they use encryption for the code. In their interest, it keeps competitors from copying their code but it also has some other benefits. More importantly for the user, it keeps the program from being mistakenly reflashed by the dealer, thus copying over the APR software and eliminating the upgrade. APR also backs their software with lifetime guarantee of free upgrades to newer programs and a lifetime warranty to cover defects in the software or soldering of the chip on the ECU. Additionally, all chip upgrades have a 30-day money back guarantee. One of the features we grew to love on Project Golf 1.8T’s APR ECU was their Enhanced Modular Chipping System (EMCS). EMCS enables APR to place several programs on the car and combines that with functionality called “Flip Switch”. Using Flip Switch, a driver can toggle between up to four different operating programs for the car. We opted for the following program options: 1 – Stock Mode 2 – 91 Octane 3 – 93 Octane 4 – Valet Mode A driver simply uses the inputs via the cruise control stalk to toggle between the various setups. We were curious about the differences between the 91 and 93 octane programs, and since we’ve never used the Race Gas program on our Project Golf, we decided against that setup this time around. Obviously, different owners have different priorities and ours was to try the new 91 octane setup vs. the 93 octane program.
We also opted for: Fault Code Erase/Throttle Body Alignment – Allows the user to erase and reset engine related trouble codes without any dealer specialty tools and also provides the ability to perform the Throttle Body Adaptation function on the vehicle. Security Lockout – Allows the user to lock out access to the EMCS and other chip functions. A four-digit pass code needs to be entered, also via the cruise control stalk, in order for any functionality to be accessed. Anti-Theft – This function allows the operator to totally lock out operation of the vehicle through control of the ECU. Even with a key, the engine will crank, but the computer will not allow ignition, making it one of the most effective theft deterrent measures you can take. Until the code is entered, the car is rendered immobile. Installation Having made our decision, the Audi was taken to the closest APR distributor. New German Performance, about 20-minutes drive north of Baltimore, MD, is one of the largest Volkswagen tuners in the Baltimore-Washington region.
While one of NGP’s techs swapped the injectors out of the car, Nate Brown of NGP went to work on the ECU. The old chip was removed and after our programs were installed, the new chip was soldered into place. With everything back together, we fired the Audi up and hit the road. Initial impressions were that there wasn’t much of a change. Our Golf had seen an almost immediate change, so the minimal difference left us inquisitive. The drive home from NGP is about two hours, and as we made our way South, we began to feel a gradual increase in power. By the next day, there was a significant increase. We attribute this increase over time to the car’s learning the new injectors. The new hardware makes this a slower process than the plug and play standard Stage I chips, so the theory seems to make sense. Driving Impressions Unlike the Stage I upgrade on our project Golf, Stage I Plus on an 8E Audi A4 isn’t as dramatic across the range. Where it really shines is torque at low rpms. Off the line the car lurches with considerably more push, seemingly now bestowed with the launching torque of a TDI. This increase in low-end torque makes the A4 considerably more driveable. While the car out of the box left us wanting, the resulting change in personality makes us confident in our choice to go with Audi’s base engine. While the A4 isn’t as much of a monster as a chipped A-chassis car, it’s still very satisfying. Chip installed, and weeks of driving with these injectors and the 93 Octane program, we chose to measure the power improvements through a dyno session. As our A4 is quattro-equipped, we couldn’t use just any dyno. A four-wheel dyno was a must, so for that we turned to a local high-performance shop in Gaithersburg, MD by the name of Altered Atmospheres.
Altered Atmospheres made their reputation in the Mitsubishi 3000 GT and Dodge Stealth performance world. While they’re probably the foremost tuner in that particular niche, stopping by their shop any day of the week, you’ll see they do work on a wide range of performance vehicles. During our visit we saw everything from tuned Subarus and new Nissan Z cars to a Quantum Syncro with an Audi turbocharged 5-cylinder engine being worked on by their staff. As any dyno numbers are reliant upon factors such as heat, humidity, drivetrain loss and dynamometer efficiency, we tend to focus on the percentage increases and not the actual numbers. With that in mind, our A4 baselined at a peak of 129.4 hp, which increased to 149.0hp (15% peak increase). Torque went from 134.7 lb-ft to 174.1 lb-ft (29% peak increase). The peak torque increase is impressive, but more impressive is the torque increase at the low end of the curve. In the 2500 rpm range, torque jumps roughly 50 lb-ft (approximately 66%), which explains the strong launches.
During a recent interview with Marco Alsterfalk of MTE, an engineer for a Swedish consulting company that does significant turbocharged Volvo ECU tuning, he shared his perspective on programming for turbocharged cars. “The relationship between power output and torque output, combined with what role they play is very important. Many people are focused on how many horsepower their car has, when in real world driving that might have little bearing on strong performance. Most people guage their performance on peak power. The trick is, you need power all through the rpm range. That is what we are after. It is horsepower that is pulling the vehicle, but you also need horsepower in the mid-range. This is represented more by the torque number, because maximum torque is usually somewhere in the mid-range. So maximum torque is generally representative of the power you have there. A wide and high torque curve is the goal. Basically, the performance you get if you examine a power vs. engine speed graph is the area under the power curve. It's not necessarily how high that curve goes at its peak height. What limits power on a turbo engine is flow related. If you have a tight catalyst, it doesn't matter how much boost you have. You still won't be able to flow more than this or that much. So aside from the turbo, and injectors, that is what is peak power limiting. It is very easy to pick up the torque in the mid-range with a turbo by raising the boost. At that low RPM, the flow through the engine isn't nearly what you have at the high end. But still, you can get it much higher, which means that the torque becomes tremendous.” Marco’s perspective, totally independent of APR and their product, points to the advantages of this style of 1.8T tuning. While the power output of the APR unit is aggressive, it may not be the most powerful program on the market. My personal preference for the APR product is more based on need for a program that has optimal day to day driveability and high reliability. Whether or not the Audi beats out all of its peers on dyno day is unimportant to me based on my own personal needs. How it passes other cars on the freeway, on the other hand, is quite important. In regards to flow, APR suggests you mate the Stage I plus with their cat-back exhaust system. It’s commonly known that a freer flowing exhaust will magnify the horsepower and torque increases on a turbocharged car, and the APR exhaust would probably do that just fine. However, while on a recent call with Audi Accessories, we learned of their new stainless steel exhaust upgrade for the A4. It being a brand-new alternative combined with our more conservative preferences for exhaust tone made trying the new system intriguing. The exhaust has been installed, and we’ll have a full review of it next week along with additional dyno numbers. © Copyright 2004 by YourSITE.com |
