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    • Champion Motorsport 997 GT3 RS MKI custom bored and stroked 4.2 liter flat-6 hits 485 wheel horsepower

      PorscheBoost member Lock N Load has been documenting his absolutely jaw dropping 997 GT3 build by Champion Motorsport. In addition to suspension and interior work he chose to have Champion build him a custom 4.2 liter flat-6 motor. Now the 997 GT3 RS MKI was already putting out a healthy amount of power from its 3.6 liter with a baseline of 396 wheel horsepower. That is over 100 wheel horsepower per liter, simply outstanding.

      What did it put out at 4.2 (4.17 to be exact) liters? 485 wheel horsepower for a gain of 89 wheel horsepower. That is all motor folks, simply phenomenal.

      To put this in perspective a factory 997.2 GT3 RS 3.8 puts out 419 wheel horsepower and the 997.2 GT3 RS 4.0 puts out 457 wheel horsepower. This exceeds the 4.0 by almost 30 wheel horsepower and Champion is not finished. They have been testing different sized throttle bodies and trying to get every last pony. With a weight in the 2800 pound range suffice it to say this car is going to move.

      This build gives us a preview of what the next generation GT3 will be able to hit as this is essentially the maximum from the flat-6. Maybe 500 wheel can be cracked but we are reaching the absolute limit. We wish to congratulate Champion Motorsport and our member Lock N Load for this incredible build and the great results so far. Simply phenomenal work.

















      The Baseline:



      After at 4.2 liters:



      GT3 RS 3.8 versus GTR RS 4.0:


      This article was originally published in forum thread: GT3 Ranger / Lock n Load Champion Motorsport 997 GT3 RS 4.2-4.3 liter engine build started by Lock n Load View original post
      Comments 88 Comments
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Yes it's a custom build. We're taking a page or two from the Manthey playbook (4.2/4.3L build).
        The oil pump clearance is the main issue in displacement limitation.

        Regarding the Porsche 911 platform/design, IMHO it is an iconic look. One thing has remained unchanged in all generations of 911's is the rear window shape.

        Ranger (Sua Sponte)
        Congrats on the project Ranger, Champion is a first rate tuner/shop/dealer.

        I haven't seen a 4.2 or 4.3 done yet so I look forward to yours being completed and the results! Keep us updated.
      1. Lock n Load's Avatar
        Lock n Load -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Congrats on the project Ranger, Champion is a first rate tuner/shop/dealer.

        I haven't seen a 4.2 or 4.3 done yet so I look forward to yours being completed and the results! Keep us updated.
        Definitely will keep you informed. This will be a major project. Not just the engine build but there will be Guard Transmission tranny rebuild, Ohlin coilover suspension and planned weight reduction.
        More to come.

        Ranger (Sua Sponte)
      1. Lock n Load's Avatar
        Lock n Load -
        Quick pics of the RS arriving at Champion Motorsport.
        Click here to enlargeClick here to enlarge
        Click here to enlargeClick here to enlargeClick here to enlargeClick here to enlargeClick here to enlargeClick here to enlarge

        The 997.1 RS made 394 rwhp as the baseline.
        Components are trickling in from all the different manufacturers.
        The RS will undergo the engine build from a 3.6L to 4.2/4.3L, redesign header/exhaust system from M&M along with full tranny re-gearing, Guard LSD, Cup shifter & shift cables, Ohlin 4 way coilover suspension, all out efforts for weight reduction (goal is 2,800 lbs), HRE building new 18" monoblock wheels plus many other smaller components.
        There's so much happening simultaneously that I am going crazy so is my wallet :-(
        Here's a pic of the Ohlins:Click here to enlarges
        As the build progresses with more components pic will be posted.
        The heart of the matter, the 4.2 crankshaft, is soon the arrive. I will not disclose yet but you'll never imagine where it's being built and I'm totally cool with it.

        Peace ya'll
        Ranger (Sua Sponte)
      1. Sorena's Avatar
        Sorena -
        AWESOME Juan.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        The 997.1 RS made 394 rwhp as the baseline.
        Do you have the graph? That is impressive.
      1. Lock n Load's Avatar
        Lock n Load -
        Here's the dynojet graph. btw the RS made this same power 2 years ago. Hadn't lost any power.
        Click here to enlarge

        Ranger
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Here's the dynojet graph. btw the RS made this same power 2 years ago. Hadn't lost any power.
        http://www.bimmerboost.com/images/im...c1d13261-1.jpg

        Ranger
        You have a 3.6 right?
      1. Lock n Load's Avatar
        Lock n Load -
        Yup that was a 3.6L 997.1 RS.
        The dyno pulls were always run on pump gas (93 oct).
        Only mod was the M&M headers and race exhaust. I know the grand majority around the forums think M&M is not even worthy to include in a discussion about exhausts. To bad ... their grave loss.

        Ranger
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Yup that was a 3.6L 997.1 RS.
        The dyno pulls were always run on pump gas (93 oct).
        Only mod was the M&M headers and race exhaust. I know the grand majority around the forums think M&M is not even worthy to include in a discussion about exhausts. To bad ... their grave loss.

        Ranger
        Tell us more about what M&M has available as I have not heard of them.

        With a 3.6 I think this build makes a lot of sense. You are looking to get in the high 400 wheel range naturally aspirated I take it?
      1. Sticky's Avatar
        Sticky -
        Moved these posts to their own thread as everyone will agree with project deserves its own thread.
      1. Lock n Load's Avatar
        Lock n Load -
        This will be a bore & stroke build. Significant head work and intake manifold is being redone. Total new design header/exhaust system from M&M.
        Compression planned to be 13:1. There are other internal machining work that Champion wants quiet. The rwhp will soon be realized. Re-gearing the entire tranny and close to 2,800 lbs should make for a quick RS.

        I will get info for you on M&M German exhaust manufacturer.

        Here's the RS with the prior M&M system in Jun 2010.

        Click here to enlarge

        Ranger
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Compression planned to be 13:1.
        So race gas only car?
      1. Lock n Load's Avatar
        Lock n Load -
        Can be but will be more specifically be tuned for 93 and 100 oct.
        Original figures were insane after the bore/stroke piston design came out to be 14.8:1. Those were stupid numbers.

        Ranger
      1. Lock n Load's Avatar
        Lock n Load -
        Here are exhaust system design that M&M has been developing for the project.
        Click here to enlargeClick here to enlarge

        This center section is "stupid loud"
        Click here to enlarge

        Ranger (Sua Sponte)
      1. inlineS54B32's Avatar
        inlineS54B32 -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Here's the dynojet graph. btw the RS made this same power 2 years ago. Hadn't lost any power.
        http://www.bimmerboost.com/images/im...c1d13261-1.jpg

        Ranger
        What amazes me is that the 400 horsepower holds for about 1500 RPM. That's an amazing engine.
      1. Yukohama's Avatar
        Yukohama -
        congrats on the build! can't wait to see this
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        Here are exhaust system design that M&M has been developing for the project.
        http://www.benzboost.com/images/impo...20isolat-1.pnghttp://www.benzboost.com/images/impo...h2520100-1.png

        This center section is "stupid loud"
        http://www.benzboost.com/images/impo...r2520Tip-1.png

        Ranger (Sua Sponte)
        Look like nice pieces, surprised they don't get more attention.
      1. 0-60Motorsports's Avatar
        0-60Motorsports -
        Champion Motorsport are a great bunch of people to deal with. Cars looks awesome bro.
      1. Lock n Load's Avatar
        Lock n Load -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Look like nice pieces, surprised they don't get more attention.
        M&M develops hardcore race exhaust systems. They're a German company who design and build top notch systems but do not have any interest in advertising. Those in the Porsche race world know who M&M is and what they bring to a race motor.
        The only US distributor is FVD. The above header/exhaust designs were developed for the build.

        Ranger
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Lock n Load Click here to enlarge
        They're a German company who design and build top notch systems but do not have any interest in advertising
        This is top notch stuff so I don't really understand what they don't advertise? I guess it doesn't matter if FVD does it for them?