Two of the most impressive V-8s to come around, um, ever, are GM’s supercharged 6.2-liter (ZR1, ZL1, CTS-V) and AMG’s twin-turbo 5.5-liter (E63, CLS63, SL63, etc.). The former, known as LS9 or LSA, offers 556 to 638 hp and 551 to 604 lb-ft of torque, while the latter, called M157, achieves 518 to 550 hp and 516 to 590 lb-ft. Both are refined, euphonious, and a pleasure to pilot, even when not motoring at Mach speed. To this short list, I add one more: Audi’s new twin-turbo 4.0-liter, aka EA 82.
I recently had the pleasure of experiencing the EA in the new 420-hp, 406-lb-ft S6 and S7, and the 520-hp, 481-lb-ft S8, and, well, whoa. Salaciously smooth and rife with spine-tingling revs and rumbles, the EA was also nabbed for duty in the Bentley Continental GT (500 hp, 487 lb-ft). But so far, it’s the S8 that’s blown us away. Why? Try 0-60 in 3.5 seconds and the quarter in 11.8 at 118.3 mph. Yes, it’s that quick.
To get a better understanding of the EA, I asked the man with the answers — Juergen Koenigstedt, head of Audi’s V-8/V-10 engines.
RK: Did you decide from the start that the new-gen Audi V-8 was going to be a 4.0-liter turbo?
JK: It was very clear that an eight-cylinder would have 4.0-liter displacement, because we have normally 500 cubic-centimeters volume in each cylinder — as in our 2.0-liter turbo engines — and it makes sense to make it in this way. We had a lot of discussion what would be the right way to have the turbo — outside or in the vee. That was a big question at the beginning and, from our point of view, this position of the turbocharger in the vee has so much advantage. You have very short way from the turbo over the intercooler into the engine. A small volume and, therefore, the throttle response is very good. Turbo lag is none.
RK: Was there any discussion about putting this new 4.0-liter in the refreshed Audi R8?
JK: Every time you have this discussion, because a few people love naturally aspirated engine with high revs and other people love turbocharged engines. From my point of view, for a real super sports car, the naturally aspirated engine, with this unbelievable throttle response and sound, is crying the high tune — that’s the R8.
RK: From the start of the Audi 4.0-liter project to now, how long was the process?
JK: Normally, we have two phases. One is the concept phase. This starts nearly four years before a project goes to start of production. And this concept phase, we have roughly 15 months. And after 15 months, you have everything together. You know how the engine will be, and you have your variables, your financial variables and so on. And then comes the decision. OK, is it good enough to make the development of the serious engines? In this case, you can say three and a half years.
RK: And how many test kilometers?
RK: Did you know from the start that Bentley would also be using the 4.0?
JK: No. It came a little bit later. Roughly a year.
RK: Were you happy that Bentley would be using the engine?
JK: At the beginning, no, because we have enough to do. And the Continental platform is different from our platforms. And at the beginning, we were a little bit afraid in comparison to the 12-cylinder engine. A 4.0-liter, is it enough for a Bentley? We had doubts at the beginning. But after a few months, when we drove the first engine in the Bentley, nobody imagines that it is a 4.0-liter engine.