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    • Race Developments UK picks up ~100 horsepower with their Audi 2.5 TFSI cylinder head work on a MKIII/8S TT-RS - Before and after dyno

      These are monster gains for cylinder head work only at this output level. AudiBoost asked Race Developments if this included any camshaft work and they stated they do not mess with the cams even for 1000+ horsepower builds.


      The head is ported and likely milled. Whatever their recipe is we do not know but it clearly pays dividends:


      Talk about a huge increase in flow up top! Power goes from 364.58 hp to 465.33 hp without any other changes other than the Race Developments head.

      Quote Originally Posted by Race Developments Uk
      Dyno results in from Australia. #audi #ttrs #8s. Engine we built a few weeks ago. Same turbo and same boost pressure. Solid 100bhp gains with increased spool too. Mapper was lost for words. Customer over the moon
      AudiBoost is at a loss for words as well.

      This article was originally published in forum thread: Race Developments UK picks up ~100 horsepower with their Audi 2.5 TFSI cylinder head work on a MKIII/8S TT-RS - Before and after dyno started by Sticky View original post
      Comments 6 Comments
      1. Arin@APR's Avatar
        Arin@APR -
        The concept is simple, though this seems excessive. Less restriction, less boost at the same airflow. Ecu only knows/measures boost and assumes airflow is low, so it runs the turbo harder until it makes the targeted boost level. That’s going to results in a ton more airflow. So, on a stock car, yeah, you could see a big gain by just bolting it on. But again, this seems excessive. Send me one!
      1. Sticky2's Avatar
        Sticky2 -
        So in essence head work drops restriction and boost and the ecu compensates so not exactly head only gains...
      1. CobraMarty's Avatar
        CobraMarty -
        Valve springs changed? How much boost?

        What does 100 and 190mph correspond to in rpm? 4500-7500rpm?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        What does 100 and 190mph correspond to in rpm? 4500-7500rpm?
        Probably close to that.
      1. Bowser330's Avatar
        Bowser330 -
        Iroz uses this place for their head work. Clearly since they hold the 2.5 Evo record, the ported heads work great.
      1. Carl Morris's Avatar
        Carl Morris -
        Click here to enlarge Originally Posted by Arin@APR Click here to enlarge
        Ecu only knows/measures boost and assumes airflow is low, so it runs the turbo harder until it makes the targeted boost level.
        Makes sense if boost is the ECU target. But I'm still surprised it makes that much difference in the midrange. I wouldn't expect head flow changes to significantly affect cylinder filling until the total flow was close to maxed out at high rpm.