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    • 600+ horsepower naturally aspirated BMW S65 V8? Yep, with the VAC V8 stroker kit (crank/displacement options of 3.5, 4.4, and 4.6 liter)

      It's a pleasure to officially introduce the VAC Motorsport stroker kit for the S65 V8 in the E9X (E90,E92,E93) M3. For those who want big naturally aspirated horsepower with the M3 this is the way to go. How much power is possible? Well, a race build with 13.5:1 compression pistons as shown in one of the dyno graphs below indicates 600+ naturally aspirated horses is possible. That is with 100 octane and a Pectel ECU to control the motor on 100 octane with 4.4 liter displacement. Now imagine that motor with some Schrick cams in the mix.

      VAC has several options and combinations available. Want to keep the stock compression ratio at 12.0:1 for a street car? No problem. Want low compression pistons for a forced induction application? You got it. Want a 3.5 liter crank to drop the stroke to rev the motor to the moon for hill climb applications? Yep, they can help you there too.

      CP or Mahle piston options are available. VAC can also supply Schrick cams as the first graph below shows a 12.5:1 4.4 liter S65 motor with 284/292 cams putting out over 500 horsepower from 7000 rpm to redline. Also talk about an impressive torque curve being held through the rev range with the cams and stroker crank. That's how it's done folks.

      Graphs, details, pricing, etc., below.


      All VAC Premium Stroker Kits feature:
      a. VAC Motorsports 82.7 billet stroker crank
      b. Arrow Precision connecting rods

      From here you can buy the kit 2 ways:
      1. With drop in Mahle pistons for stock bore. Buy here

      2. With CP pistons and Darton sleeves. Buy here This requires a top level machine shop to fit the sleeves. We offer this service on our all new Centroid for the highest level of accuracy and consistency. PM for more info.

      Bonus: 4.6L capability! With these sleeves you can go to a 94mm piston, combined with the stroke yield a stout 4.6L S65.

      We generally always have cranks and rods in stock. We often have pistons in stock as well, though we run through these quicker so there may be a 3-10 week delay depending on manufacturer and demand.

      For those in a rush, we offer up to a 3 day expedite on CP Pistons. :-) No expedite on Mahle pistons.

      We have sold these to street, circuit, hill climb and rally clients. With and without sleeves. Low compression, high compression - the sky is the limit.

      Side note: We will have our 3.5L S65 cranks in stock soon. Another thread will follow ;-)

      A few dyno sheets:









      This article was originally published in forum thread: VAC Motorsports | S65 4.4L / 4.6L Stroker Kit started by Mike@VAC View original post
      Comments 40 Comments
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Flinchy Click here to enlarge
        just like to say this is HILARIOUS

        dinan's 4.6 makes all of 375whp.. and.. RDsport's isn't much better
        Dinan just has a weak tune and the RDSport stroker has hit 441 whp on stock cams...
      1. Flinchy's Avatar
        Flinchy -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Dinan just has a weak tune and the RDSport stroker has hit 441 whp on stock cams...
        ah 441 isn't so bad

        i'm just referring to the latest comparison i've seen floating around, where neither stroker kit was particularly impressie
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Flinchy Click here to enlarge
        ah 441 isn't so bad

        i'm just referring to the latest comparison i've seen floating around, where neither stroker kit was particularly impressie
        The hardware is good Dinan and RDsport both suck at tuning. Well, Dinan has the resources to have the best but their street tunes are weak.
      1. deemo319's Avatar
        deemo319 -
        Click here to enlarge
      1. klipseracer's Avatar
        klipseracer -
        So Pectal? Thats an amazing piece of work right there, but the pectals are pretty spendy if I remember correctly. Not saying this is a bad deal, but hints at the price. Was this mentioned anywhere?
      1. Irishace's Avatar
        Irishace -
        In for more about the S52 kit. That looks very interesting indeed. Great work on the S65 kit.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by klipseracer Click here to enlarge
        So Pectal? Thats an amazing piece of work right there, but the pectals are pretty spendy if I remember correctly. Not saying this is a bad deal, but hints at the price. Was this mentioned anywhere?
        That motor is obviously for a race car where you want precise engine management. The hardware is still compatible with the stock DME easily.
      1. Mike@VAC's Avatar
        Mike@VAC -
        These are race cars and the dyno sheets are from engine dynos.

        We have stock DME street tunes now ;-) No power figures yet, hopefully this summer.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Mike@VAC Click here to enlarge
        We have stock DME street tunes now
        By whom?
      1. Marz's Avatar
        Marz -
        Click here to enlarge nice job VAC with this crazy power on the S65! Are you guys running a motec in this car? 600 HP n/a Congratz! As mentioned above I would like to see some dynojet numbers for a good comparison to other kits out there!!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Marz Click here to enlarge
        Click here to enlarge nice job VAC with this crazy power on the S65! Are you guys running a motec in this car? 600 HP n/a Congratz! As mentioned above I would like to see some dynojet numbers for a good comparison to other kits out there!!
        We will eventually just right now these motors go into race cars and not street cars.
      1. benzy89's Avatar
        benzy89 -
        Would love to see an @evolve supercharger combined with the VAC stroker kit... Would put down some serious power & a ton of low end grunt
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by benzy89 Click here to enlarge
        Would love to see an @evolve supercharger combined with the VAC stroker kit... Would put down some serious power & a ton of low end grunt
        Harrop twin screw 4.6 VAC stroker
      1. Lock n Load's Avatar
        Lock n Load -
        This looks great. Pectel ECU is mentioned but from experience and recollection with Audi World Challenge race cars, Pectel ECU can cost $20K. They have almost limitless capability. These engines with Schrick cams and larger diameter equal length header primaries would be an awesome NA set up.
        RWHP should be in 520 to 540 range.
        Look forward to a running M3.

        Ranger (Sua Sponte)
      1. VCMPower's Avatar
        VCMPower -
        Is the stock DME tunes by who you have been using for most the stock dme you need tuned? if so it will be a solid tune Click here to enlarge

        Click here to enlarge Originally Posted by MikeVAC Click here to enlarge
        These are race cars and the dyno sheets are from engine dynos.

        We have stock DME street tunes now ;-) No power figures yet, hopefully this summer.
      1. klipseracer's Avatar
        klipseracer -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        That motor is obviously for a race car where you want precise engine management. The hardware is still compatible with the stock DME easily.
        AHH, I thought pectal was required. Thanks for clearing that up.
      1. M-Theory's Avatar
        M-Theory -
        I will be looking into this with a S/C combination, great work guys the "other" stroker kits out pushed me away but this is amazing!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by M-Theory Click here to enlarge
        I will be looking into this with a S/C combination, great work guys the "other" stroker kits out pushed me away but this is amazing!
        Welcome. Well to posting that is.
      1. leveraged sellout's Avatar
        leveraged sellout -
        This + twin turbos or a great S/C setup could be devastating. Can't wait to see well over 1k at the wheels in an E9x.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by leveraged sellout Click here to enlarge
        This + twin turbos or a great S/C setup could be devastating. Can't wait to see well over 1k at the wheels in an E9x.
        Soon... very soon.