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    • Audi's 4.0 TFSI Twin Turbo V8 showing its tuning potential - Already over 600 wheel horsepower tune only (APR)

      The German turbo V8 era sure is getting fun with Mercedes-Benz, BMW, Audi, and Porsche all going back and forth in a turbocharged V8 power war. Audi has the motor with the smallest displacement of the bunch but it is hardly giving up much of anything to its larger V8 competition. Proof? How about over 600 horsepower at the wheels with just a tune? APR was able to get exactly that with their Stage I ECU upgrade and 100 octane race fuel in the new S8 hitting 610 horsepower at all four wheels.

      We all saw last week that the Audi S8 is already in the 10's in the 1/4 mile tune only courtesy of APR. Below you have dynographs for the Audi S8 stock on 91 octane, Stage I on 91 octane, Stage I on 93 octane, and Stage I on 100 octane race fuel. The S8 puts down an impressive 485 all wheel horsepower completely stock on 91 octane showing it is slightly underrated to begin with.

      This all begs the question as to how the 4.0 TSFI V8 differs in various applications. This same basic V8 is used in the S6 and S7 tuned to 420 horsepower. In the S8 this output rises to 520 horsepower. In the RS6/RS7 this output rises to 560 horsepower. It is safe to assume the S8 has different turbos on the 4.0 than the S6/S7. Does the RS6 and RS7 then have different turbos than the S8? What exactly are the differences between the 4.0 TFSI in all the models it is used in at different horsepower levels? AudiBoost hopes to find out. What is certain is that this motor is capable of serious power with only mild modifications.

      Audi S8 Dynographs below.

      91 Octane:


      93 Octane:


      100 Octane:


      Performance Figures:

      This article was originally published in forum thread: Audi's 4.0 TFSI Twin Turbo V8 showing its tuning potential - Already over 600 wheel horsepower tune only (APR) started by Sticky View original post
      Comments 12 Comments
      1. Adrenacide's Avatar
        Adrenacide -
        Beastly! I went to the JHB motor show last weekend and got to see an RS7 in person, damn, it's pretty!
      1. ezec63's Avatar
        ezec63 -
        @Sticky wow very similar numbers to a tuned M157 and very similar power curves that show big torque down low and fade out a bit up. They also have the same low revving nature just barely going over 6K rpm. Really want to see what they can do with the 7000rpm in the s63tu
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by ezec63 Click here to enlarge
        @Sticky wow very similar numbers to a tuned M157 and very similar power curves that show big torque down low and fade out a bit up. They also have the same low revving nature just barely going over 6K rpm. Really want to see what they can do with the 7000rpm in the s63tu
        It also has top mounted turbos...
      1. ezec63's Avatar
        ezec63 -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        It also has top mounted turbos...
        The S63 tu or the 4.0 VW motor? These F/I v8 cars are ridiculous with basic mods would love to see this with intake and full exhaust/ catless down pipe
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by ezec63 Click here to enlarge
        The S63 tu or the 4.0 VW motor? These F/I v8 cars are ridiculous with basic mods would love to see this with intake and full exhaust/ catless down pipe
        The VW motor.

        Click here to enlarge
      1. SpeedLimit?'s Avatar
        SpeedLimit? -
        @Sticky, any idea what turbos they use? Same question for the m157 & s63tu as well.
      1. Roadkillrob's Avatar
        Roadkillrob -
        I have a friend with an S7 and he had APR flash it 2 weeks ago to a claimed 560 hp, it goes like he'll now that is for sure!
      1. chrisisnapping's Avatar
        chrisisnapping -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Gorgeous bay. I can't wait to see what APR may do with this engine, they can work some magic on that turbo set up.

        I need to start saving my pennies and switch over to Audi, I'll even settle for a S4 with DSG.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by SpeedLimit? Click here to enlarge
        @Sticky, any idea what turbos they use? Same question for the m157 & s63tu as well.
        This is what I hope to learn.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by chrisisnapping Click here to enlarge
        Gorgeous bay. I can't wait to see what APR may do with this engine, they can work some magic on that turbo set up.

        I need to start saving my pennies and switch over to Audi, I'll even settle for a S4 with DSG.
        Having APR on your side for the twin turbo V8 is a damn good thing as they'll probably get a turbo upgrade working before anyone does for the BMW.
      1. chrisisnapping's Avatar
        chrisisnapping -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Having APR on your side for the twin turbo V8 is a damn good thing as they'll probably get a turbo upgrade working before anyone does for the BMW.
        the perks of being a Large international company with the top tools and engineers. APR is just on another level, it's a shame they don't put too much effort into the R8 or Porsches.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by chrisisnapping Click here to enlarge
        the perks of being a Large international company with the top tools and engineers. APR is just on another level, it's a shame they don't put too much effort into the R8 or Porsches.
        Their supercharger is coming for the R8 but I think it's a good thing they maintain a strict focus.