• Harrop Engineering doing the "impossible" - Introducing the world's first positive displacement E92/E90/E92 S65 V8 supercharger

      Wow. That is exactly what came out of my mouth when I saw this supercharger kit at Bimmerfest. In all honesty, it was my main motivation for attending the event once I heard it would be there. Some people may be reading this and wondering what the big deal is as superchargers already exist for the M3. That is true, superchargers do exist, but they are all centrifugal style blowers. This is the world's first positive displacement supercharger for the S65 V8.

      Why is that a big deal? Because it's a completely different type of blower with completely different power delivery. This is the solution for those who complain about the M3's torque or for those who do not like the response down low of a centrifgual blower which needs rpm to make boost. This style of supercharger is always making boost, from anywhere in the rev range.

      That is what makes incorporating it on the S66 V8 difficult with its independent throttle bodies as positive displacement blowers usually are set to pull air through a throttle body not blow into it. The centrifugal blowers send air into a manifold. If a positive displacement were to use a similar setup it would be blowing air in while the throttle bodies attempted to close as it is always making boost. See the problem?

      The solution Harrop Engineering came up with was a manifold that fits in between the throttle bodies with a bypass valve fit that relieves pressure as needed and makes sure boost is not made as throttles are closing. Pretty trick setup eh? You can see the design in the photos and also how tight the packaging is. I do not even want to know how many hours were put in trying to get this all to fit.

      The blower employed is a TVS1740 unit from Eaton. This is a roots blower and likely will be set to 5.5 psi or so initially. Boost from this blower is different from a centrifugal and will be harder on the stock rods since it is at full boost right away. Expect horsepower in the low 500's to the wheels.

      Oh and see that little black box to the left of the manifold off a metal area at the inlet? There will be electronic boost control which is likely the first of its kind on a positive displacement setup although I am not able to confirm this. Different maps with different boost levels for different fuel? A possibility, yes.

      This is a big deal and an engineering feat for the S65. My complete and utter respect and that of this network to the guys at Harrop. There is still work to be done here. It is not quite ready although pricing is initially set at $12,990. There is still a lot of tuning to be done but this will be coming eventually.

      Pictures below, much respect Harrop and it was a pleasure meeting you guys at Bimmerfest. You were incredibly nice and answered all my (MANY) questions. Thank you:























      This article was originally published in forum thread: Harrop Engineering Twin Screw S65 V8 Supercharger started by CookieCrisp View original post
      Comments 276 Comments
      1. fastgti69's Avatar
        fastgti69 -
        Kit looks great, can't wait to see the numbers and that curve difference.
      1. kiln's Avatar
        kiln -
        Click here to enlarge Originally Posted by Clayton@Harrop Click here to enlarge
        It is alive.. I was going to post the short video of the development car on our hub dyne yesterday but I can't post links as a guest vendor..
        When can we expect more details?
      1. Clayton@Harrop's Avatar
        Clayton@Harrop -
        Shouldn't be to far away. We have been running the car for quite a while now but would like to have everything sorted before posting data.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Clayton@Harrop Click here to enlarge
        It is alive.. I was going to post the short video of the development car on our hub dyne yesterday but I can't post links as a guest vendor..
        That's ok got you covered: http://www.bimmerboost.com/content.p...er-kit-running
      1. bobS's Avatar
        bobS -
        @LostMarine @benzy89

        Not sure if you guys realize this but that blue m with this kit is owned by a guy in nj. Long beach island nj according to that article in europeancar magazine. My parents and my wife's parents have houses there, I'm there every weekend in the summer yet I've never seen that car.

        Hopefully I run into him one day and can ask him about this kit......
      1. benzy89's Avatar
        benzy89 -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        Hopefully I run into him one day and can ask him about this kit......
        I think he said the blower's been "temporarily removed" while Harrop finalizes the tuning, which makes sense considering he's got a DCT & nobody wants to replace a $9.5k trans.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by benzy89 Click here to enlarge
        I think he said the blower's been "temporarily removed" while Harrop finalizes the tuning, which makes sense considering he's got a DCT & nobody wants to replace a $9.5k trans.
        Well I don't mind playing with the trans.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Well I don't mind playing with the trans.
        Hah
      1. mfatuation's Avatar
        mfatuation -
        Click here to enlarge Originally Posted by bobS Click here to enlarge
        @LostMarine @benzy89

        Not sure if you guys realize this but that blue m with this kit is owned by a guy in nj. Long beach island nj according to that article in europeancar magazine. My parents and my wife's parents have houses there, I'm there every weekend in the summer yet I've never seen that car.

        Hopefully I run into him one day and can ask him about this kit......

        The article had a coupe of inaccuracies. The date of the storm was incorrect, and I live in Toms River, not "Barnegat Bay"...

        I've actually only had the car at LBI once, when I made a run to CHEG. Click here to enlarge
      1. mfatuation's Avatar
        mfatuation -
        Click here to enlarge Originally Posted by benzy89 Click here to enlarge
        I think he said the blower's been "temporarily removed" while Harrop finalizes the tuning, which makes sense considering he's got a DCT & nobody wants to replace a $9.5k trans.
        This is correct.
      1. bobS's Avatar
        bobS -
        Click here to enlarge Originally Posted by mfatuation Click here to enlarge
        The article had a coupe of inaccuracies. The date of the storm was incorrect, and I live in Toms River, not "Barnegat Bay"...

        I've actually only had the car at LBI once, when I made a run to CHEG. Click here to enlarge
        Nice! My inlaws shore house I stay at every weekend is 10 blocks from the cheg... hah. Small world. Your car is very nice, you should post some pics up on here. I'm in the process of selling my 335 and moving to a m3 so i'm looking for ideas t mod my future e92 m. I was surprised when I was reading that article and saw "LBI nj".
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by mfatuation Click here to enlarge
        This is correct.
        Would you mind sharing when it was removed? Have you been able to drive it with the blower at full power at all? @mfatuation
      1. mfatuation's Avatar
        mfatuation -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Would you mind sharing when it was removed? Have you been able to drive it with the blower at full power at all? @mfatuation
        It was only on for a matter of weeks, and it was only driven from Supreme Power to Bimmerfest, then from Supreme Power to the photoshoot location for European Car. Very negligible mileage. It was never on a dyno (there was no reason for it to be). The car was making no boost, but just to be safe it had a conservative tune, reduced rev limit, etc... While I went out to California to check in on the build and attend Bimmerfest, I had to leave early and accomplished neither.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by mfatuation Click here to enlarge
        It was only on for a matter of weeks, and it was only driven from Supreme Power to Bimmerfest, then from Supreme Power to the photoshoot location for European Car. Very negligible mileage. It was never on a dyno (there was no reason for it to be). The car was making no boost, but just to be safe it had a conservative tune, reduced rev limit, etc... While I went out to California to check in on the build and attend Bimmerfest, I had to leave early and accomplished neither.
        I see, thanks.
      1. Mike@VAC's Avatar
        Mike@VAC -
        Click here to enlarge Originally Posted by mfatuation Click here to enlarge
        It was only on for a matter of weeks, and it was only driven from Supreme Power to Bimmerfest, then from Supreme Power to the photoshoot location for European Car. Very negligible mileage. It was never on a dyno (there was no reason for it to be). The car was making no boost, but just to be safe it had a conservative tune, reduced rev limit, etc... While I went out to California to check in on the build and attend Bimmerfest, I had to leave early and accomplished neither.
        Hey dude, nice meeting you Saturday!
      1. mfatuation's Avatar
        mfatuation -
        Click here to enlarge Originally Posted by Mike@VAC Click here to enlarge
        Hey dude, nice meeting you Saturday!
        Likewise Mike! I'll have the pics up on my site soon, only had a chance to edit and upload the Rogue Engineering shots so far. Click here to enlarge

        www.mfatuation.com