Audi 4.0T V8 Performance: S6, S7, S8, RS7
As the automotive industry moves forward there is a constant trend towards smaller and more fuel efficient engines. For lots of us purists we meet these changes with a bit of a grimace, not that we don’t enjoy and appreciate the technological progress of making similar power with less and less displacement but there is something attractive about big engines, with lots of cylinders that make great sounds and have smooth even power delivery like the Audi 4.0T.
Fortunately for the performance aftermarket and environment alike, the trend towards decreasing engine size doesn’t always mean decreased performance. In some instances like Audi’s 4.0t V8 it means we truly get the best of both worlds. This engine is offered in a multitude of chassis, the Audi S6, S7, RS7, A8, S8. Bentley, another brand under the Volkswagen Audi Group umbrella also uses this same power plant.
Our go-to performance partner for the Audi 4.0T platform is APR. They have developed a few pieces of hardware and software that truly transform this power plant from something that is impressive in stock form to something that is truly amazing.
It’s not often that the first step in the upgrade path can be one of the most significant, but with a factory forced induction (specifically turbocharged) engine, massive gains can be made just by installing proper ECU tuning software. Stock, the engine produces 480 hp and 451 ft/lbs of torque at the crank. These are impressive numbers, but leave a LOT of power on the table.
Here is one customer’s Audi 4.0T RS7 Receiving its APR Stage 1 ECU Upgrade:
How much you ask?
ECU calibration from APR with their 4.0T “Stage 1 software” those numbers climb to 563 HP and 627 ft/lbs of TQ, with peak gains of over 125 HP and 187 ft/lbs of torque!
Just to be clear the peak numbers are not that high but the areas between the dyno plots of the car pre and post tuning have maximum increases of 125/187. This is significant, that equates to over a 26% increase in hp and a 41 percent increase in torque.
Beyond adding power APR has also managed to crack into and has the ability to tweak the Audi 4.0T TCU, the computer that is responsible for controlling the transmission attached to the mightily impressive 4.0T Engine! The TCU upgrade goes far beyond jut raising rev limits and actually changes the logic and operation of how and when and why the transmission shifts. Advantages include; faster acceleration, user adjustable launch control, user definable downshifts and upshifts, faster shifting, smoother shifting, temperature management benefits, amongst many offers.
This is all realized with NO hardware changes, just a simple computer flashing techniques that work through the cars OEM OBD II port located conveniently under the dash. It really is quite remarkable how much performance can be unlocked without even opening the hood on these cars!
For those wanting a bit more than what the ecu software alone allows for the second setup up involves a hardware change. APR’s Stage 2 for the Audi 4.0T is comprised of a set of High Flow downpipes, in combination with a revised tuning file for the ECU.
S6 4.0T with the Old Stock Units Removed:
APR Stage 2 Units installed in the same Audi S6:
In a turbocharged car, the downpipes are one of if not the single biggest restrictions in the stock cars. The downpipe is the section of exhaust that connects the turbocharger to the cat-back section of the exhaust. Although some companies like to remove catalytic converters, both APR and RSW don’t believe that performance at the price of legal or emissions ramifications is worth it. Whenever we install or recommending installing aftermarket exhaust’s on performance applications we recommend a high flow compliant catalytic converter that achieves 95 percent of the gains of a gutted pipe without the emissions, noise, smell, and other issues that come along with removing a catalytic converter from the exhaust path.
RS7 with the same downpipes installed almost identical, but a few small differences:
Close-up, but from the opposite side:
After installing the downpipes and loading the stage 2 mapping the car gains 176hp/258 ft lbs of torque peak over a stock car. That brings the total peak numbers up to 586 hp and 694 ft lbs of torque. That is SERIOUS power for any car, but the beauty of the 4.0T V8 platform is that the engine, chassis, and transmission can all put the power to the ground very effectively.
If you have any questions about modifying or improving your 4.0T equipped Audi please do not hesitate to reach out to your Performance Specialists here at RSW. We have performed countless upgrades to these vehicles, and are even capable of providing more extreme levels of performance and modification if warranted.