The focus of AWE power production is on bolt-on parts and chip tuning. "When you're tuning the cars, you really have to have somebody who understands the chip tuning and the ECU," said Todd. "That's usually the limiting factor with these newer cars. On some cars, you can't change the exhaust unless you couple it with chip tuning, because there are special adaptive modes that may tune out any advantage you thought you had made by installing a higher performance part. Sometimes the ECU will shoot for the parameters it thinks it needs to see, and in the process it may negate whatever power advantage may have been made by the parts if the corresponding chip changes had accompanied it. The Bosch DME 7 in the S4 is highly adaptive, but when Audi went to the drive-by-wire throttle it complicated things quite a bit. You could increase boost and the DME 7 would shut down the party by turning back the throttle. It thinks, 'This isn't supposed to be happening, we aren't supposed to be seeing these mass airflow readings!' So unless you really have someone that's knowledgeable in this area, you're doomed to making claims without being able to back them up."
The chip-tuning support AWE uses is known throughout the industry, as Todd explained: "The chip programmer we are partnered with is GIAC, Garrett Integrated Automotive Corp. We're actually its oldest and largest distributor. We work with the company, as we have a dyno that allows us to collect a lot of data, so we can go back to GIAC to achieve the kinds of changes we are looking for through the chip tuning." GIAC performs all the programming to the parameters specified by AWE Tuning. All three of these cars, which are in very different states of tune, use GIAC software in their Bosch Motronic 7 ECUs.
This results in three different versions of software, one for each car represented here. Todd explained, "The car with the carbon hood is running with its stock KO3 turbos, and it has a prototype front-mounted intercooler, our downpipes and a cat-back exhaust. That has the standard, off-the-shelf "X-chip," which is available to all S4 owners. It's a production GIAC chip AWE uses all the time. The black wagon has been upgraded with a KO4 turbo set from the Europe-only RS4 and has the proper GIAC chip to accompany the upgrade.
Todd estimates the other silver S4, the one he calls the Silver Bullet, is making around 550 bhp. It hasn't been on a chassis dyno, so the car's quarter-mile acceleration and speed, along with weight and aerodynamics, are used to arrive at an approximation. "The RS4 K04 turbos," he said, "are completely different than the K04s the factory uses with 1.8ts, with a different compressor wheel and housing." Turning to the software, "The Silver Bullet is running a highly specialized chip-there is a lot of crazy programming in there! It takes into account the boost and ignition curves we're using to arrive at that level of power, with the intercoolers that make it possible. It is basically a one-off chip GIAC developed for us. We were able to learn a lot about the drive-by-wire system in the S4 with that chip. It immediately showed us where we needed to look to go further, even with the stock KO3 turbo cars. Chipping these turbo cars is pretty complex; it's not just a matter of getting the correct boost, fueling or advance by themselves-all the parameters have to be right for the performance level you're after," Todd said.