When is the last time you were on a large Boeing or Airbus airliner? Think back to that time. Think about boarding and taking your seat, pushing back from the gate and taxiing out to the runway for departure. If you’re lucky, you don’t have to wait in cue for long and when you arrive at your runway, you feel the plane make a sudden 90 degree turn and then stop to position itself at the ready awaiting approval from the tower for takeoff. After a few moments, the engines roar to life, thrust builds and almost immediately your whole body is firmly pressed into the seatback as you power down the runway. That same physics defying feeling of relentless and consistent power… that is what the S7 with APR’s 4.0 TFSI ECU upgrade feels like.
Let’s talk engines. For years now Audi has given us some tremendous forced induction powerplants. First the 2.0 TFSI in the TTS, next the 2.5 TFSI in the TT RS. More recently, the supercharged 3.0 TFSI that powers the S4 and S5 has made a lot of fans with its suspected higher than published output. Most recently, Audi went to the next level with its 4.0 TFSI engine. A 4-liter V8 with twin turbos that powers not only the S7 here in the US market, but also the S6, RS 7 and S8.
Let’s talk numbers. No matter what way you choose to look at the new 4.0 TFSI, its output is phenomenal and like the 3.0 TFSI, it seems that Audi was a bit more than coy on reporting horsepower and torque figures. Claimed crank horsepower from the factory is 420 hp. Claimed torque is 406 lb-ft. However, when APR did its benchmark dyno testing on its own in-house S7 development car, they found something a bit….more. 60 horsepower and 58 lb-ft of Torque more! APR’s own S7 put down 480 hp and 464 lb-ft at the crank. At the wheels, those numbers where 403 hp and 431 lb-ft! This may help explain the magazine tests reporting 0-60 times in the high 3s, almost ¾’s of a second quicker than the 4.6 sec published by Audi. Finally, this power is delivered to a car that was equipped with 40/60 rear bias Quattro all-wheel drive, an S-tronic dual clutch transmission with launch control. When combined with the boosted V8, the car is unstoppable and has the ability to dispose of many higher horsepower rear wheel drive cars instantly – more on that later.
As potent as the S7 is however, Alabama based APR Tuning can make it more so. APR’s extensive research and development provides owners with a powerful ECU upgrade with no loss of drivability or reliability. One can expect faster acceleration, improved throttle response and more power across the entire power band.
For the 4.0 TFSI engine, APR uses a recalibrated engine control strategy that primarily remaps the engine’s operating parameters, within the factory ECU in order to provide smooth and reliable power as if intended by Audi. APR’s ECU upgrade is developed to work within the OEM and Tier 1 Supplier specifications for engine component stress tolerances and performance specifications. Further, depending on customer needs and location, APR has developed programs for 91 octane, 93 octane, 100 octane race fuel and even a valet mode to limit performance to approximately 40mph and 5,000 RPM if you are away from your car. Other functionality per APR out of the box include, Anti Theft Programs, Security Lockout and also Fault Code erase – moving forward, this can all be controlled via APR’s brand new Mobile App.
For Project S7, we chose to retain the stock setting as well as the 93, 100 octane and valet programs. This is done through a bench tuning process where the factory ECU is removed from the car and attached to the computer system of an Authorized APR distributor, in our case – Brink Motorsports in Austin TX. The process is seamless and efficient, taking about an hour to complete. Once done, the owner can toggle through each of the APR programs by using the cruise control stalk.
Let’s talk gains. The APR Stage I ECU upgrade provides peak crank output of 560 HP/580 TQ on 93 octane and up to 569 HP/605 TQ on 100 octane race fuel. As much as 124 HP and 163 lb-ft of torque are available through the power band. Wheel numbers are just as impressive – 478 hp/536 lb-ft on 93 octane and 490 hp/565 lb-ft on 100 octane race fuel. Performance to 60 and 100 is shaved by an additional half and full second respectively with trap speeds in the ¼ mile increasing by almost 6 mph. Below are two videos of an S7 in Stock and 93 octane tuned form performing ¼ mile testing and a trick speedometer and tachometer overlay depicting the same.
I have now logged 4,000 miles on the car since the APR tune, including 3,000 miles to Las Vegas and back for the 2013 SEMA Show. The smooth drivability I’d come to expect is retained but the car can transform itself at a stoplight like few things on the road if and when called upon. I won’t name names but many high horsepower domestics including some “Z’s and GT’s” as well as some German “M’s and AMG’s” simply can’t keep pace from launch. It’s the same Boosted + All Wheel Drive + Dual Clutch Transmission combo that makes the GT-R or the Porsche 911 Turbo so stout . The difference is, I might have a load of groceries, a Christmas tree or my 7 year old daughter in the back of the car – who will be sure to roll down her window and wave at them come the next stop light! Not bad for a 16 foot long, 4,500lb Sportback that, by the way, got nearly 28 MPG on the way to Nevada and back thanks to Audi’s cylinder deactivation technology.
Finally, APR has recently completed the 4.0 TFSI software for all of the other engines in Audi’s lineup. This includes A8, S8, S6 and RS 7 as well. In doing so, they’ve hinted at an update coming to the existing S6 and S7 software, which should deliver even more power than they are currently producing! Thankfully for our car and all of their other customers, APR offers these upgrades and advancements for free.
Project S7 will continue to develop as the Brink Motorsport exhaust is being refined from Rough Draft to Final Copy all while a bespoke trick intake system is being developed!
…as for APR… the car is Stage I, for now….