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    • 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. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        It was already mentioned by me and others the tuning would be close to having tune for a turbo in the respect of how the boost comes in versus how you tune based on rpm set point with a centrifugal. So you're rehashing what was stated again?
        well, kinda just re-enforcing how similar they are, and if an educated guess by an educated person might label it about 70% similar, fine tuning always making up the diference
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        well, kinda just re-enforcing how similar they are, and if an educated guess by an educated person might label it about 70% similar, fine tuning always making up the diference
        Tuning a positive displacement and turbo setup are "X%" similar to you?
      1. Clayton@Harrop's Avatar
        Clayton@Harrop -
        Ok Guys - while we continue work towards production release here is some more info about us and the kit given so much speculation:

        • We are utilising Eaton TVS technology as used on OE models such as ZR1 Corvette, ZL1 Camaro, CTS-V, Audi 3.0T, Ford GT (Aust) & Lotus etc etc
        • This is roots style positive displacement technology, not a twin-screw compressor
        • Harrop currently OE supply Ford in Australia and Lotus Cars UK with supercharger systems
        • Harrop is a supplier to APR for their Audi 4.2L Stage 3 kit using our 1320 supercharger
        • The R1740 supercharger is the latest displacement release rotating assembly by Eaton that is destined for an OE platform to be announced later this year
        • Initial development was based around the 1320 supercharger but deemed too small once the 1740 was known to be available
        • We have developed electronic boost (by-pass valve) control which is a world first for aftermarket positive displacement supercharger kit design
        • The supercharger outlet position is located in the centre of the supercharger plenum. This in combination with a large plenum volume and 2 high fin density intercooler cores ensures that air distribution in the manifold is uniform
        • For calibration we have a development kit on our car in Australia and another in the US, we are working with a number of tuning resources locally and in the US to deliver a production calibration with the ultimate goal of ultimate drivability

        We look forward to sharing more insights to the development and performance gains over the coming months... stay tuned..
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Tuning a positive displacement and turbo setup are "X%" similar to you?
        yes, and to the rest of the world
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by Clayton@Harrop Click here to enlarge
        Ok Guys - while we continue work towards production release here is some more info about us and the kit given so much speculation:

        • We are utilising Eaton TVS technology as used on OE models such as ZR1 Corvette, ZL1 Camaro, CTS-V, Audi 3.0T, Ford GT (Aust) & Lotus etc etc
        • This is roots style positive displacement technology, not a twin-screw compressor
        • Harrop currently OE supply Ford in Australia and Lotus Cars UK with supercharger systems
        • Harrop is a supplier to APR for their Audi 4.2L Stage 3 kit using our 1320 supercharger
        • The R1740 supercharger is the latest displacement release rotating assembly by Eaton that is destined for an OE platform to be announced later this year
        • Initial development was based around the 1320 supercharger but deemed too small once the 1740 was known to be available
        • We have developed electronic boost (by-pass valve) control which is a world first for aftermarket positive displacement supercharger kit design
        • The supercharger outlet position is located in the centre of the supercharger plenum. This in combination with a large plenum volume and 2 high fin density intercooler cores ensures that air distribution in the manifold is uniform
        • For calibration we have a development kit on our car in Australia and another in the US, we are working with a number of tuning resources locally and in the US to deliver a production calibration with the ultimate goal of ultimate drivability

        We look forward to sharing more insights to the development and performance gains over the coming months... stay tuned..
        OE supplier for Ford Aus and Lotus? nice.

        It looks to me like Harrop has the resources and experience needed to make this an outstanding product. Good luck with your progress.

        I know someone with an M3 who will jump all over this once its for sale. I'll make sure she knows all about this kit Click here to enlarge
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        yes, and to the rest of the world
        You can't just slap a number on tuning similarities between two different boost delivery mechanisms, even if they are similar in some respects. You can only go as far as saying there are similarities. Saying they are 70% similar to tune is, in my opinion, assuming too much. If the same tuner tunes the same two engines (say an s65) with a turbo and with a PD blower and then says "yeah they were similar to tune in some respects. Id say about 70% similar" I will change my opinion.
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by DFM Click here to enlarge
        You can't just slap a number on tuning similarities between two different boost delivery mechanisms, even if they are similar in some respects. You can only go as far as saying there are similarities. Saying they are 70% similar to tune is, in my opinion, assuming too much. If the same tuner tunes the same two engines (say an s65) with a turbo and with a PD blower and then says "yeah they were similar to tune in some respects. Id say about 70% similar" I will change my opinion.
        why cant i? whats different? emphasize your case
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        why cant i? whats different? emphasize your case
        Just want to start out by saying im not trying start an argument. I would honestly be happy if you changed my mind, because that means I learned something about F/I tuning.

        Whats different? time to full boost, exhaust manifold pressure (not sure if this affects combustion chamber scavenging during overlap), attainable boost level under full and partial load, relationship of flow velocity:flow volume, boost control (yes this PD S65 also has boost control, but it controls boost by venting charged air vs manipulating the flow of exhaust gasses), heatsoak variances that could raise IAT's and induce detonation.

        Now these differences came from me and what I know about IC engines and the variables that affect their performance. That being said, I could be wrong on some if not all (doubt it) of the differences.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Clayton@Harrop Click here to enlarge
        Harrop is a supplier to APR for their Audi 4.2L Stage 3 kit using our 1320 supercharger
        Will this include APR's 1740?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        yes, and to the rest of the world
        What you're saying doesn't make any sense and doesn't provide any tuning information on the setups. By logic all forced induction setups are X% similar and it really doesn't say much of anything. It's just a hollow statement and rather pointless but let's get to actual substance in this thread now that actual substance not pointless % estimates was posted.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by DFM Click here to enlarge
        You can't just slap a number on tuning similarities between two different boost delivery mechanisms, even if they are similar in some respects. You can only go as far as saying there are similarities. Saying they are 70% similar to tune is, in my opinion, assuming too much. If the same tuner tunes the same two engines (say an s65) with a turbo and with a PD blower and then says "yeah they were similar to tune in some respects. Id say about 70% similar" I will change my opinion.
        Don't try and use logic.
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by DFM Click here to enlarge
        Whats different? time to full boost, exhaust manifold pressure (not sure if this affects combustion chamber scavenging during overlap), attainable boost level under full and partial load, relationship of flow velocity:flow volume, boost control (yes this PD S65 also has boost control, but it controls boost by venting charged air vs manipulating the flow of exhaust gasses), heatsoak variances that could raise IAT's and induce detonation.
        there we go, a conversation

        time to full boost. how does the PD and Turbo differ? this is assuming a properly sized turbo to eliminate any lag- considering stock motor s65 cant take any high boost anyway
        we've seen IIRC 2500rpm for the PD. i cant imagine a turbo hitting full boost much after that- (~8 psi)

        Click here to enlarge Originally Posted by DFM Click here to enlarge
        attainable boost level under full and partial load,
        we know we are working with a MAX of 9 psi, id say even 8 psi on the PD, and the same with a properly matched turbo, how soon can the S65 spool a Turbo, whats the relationship between spooling a turbo to full boost Vs the centri's Vs the PD, which (given the above) are very very similar

        partial load- given the above-T-spool vs PD boost should be very close no? much MUCH closer than a centri, yes?



        Click here to enlarge Originally Posted by DFM Click here to enlarge
        relationship of flow velocity:flow volume,
        as a function of? CFM? need to know a turbo size, but cant be that big right Click here to enlarge



        Click here to enlarge Originally Posted by DFM Click here to enlarge
        boost control (yes this PD S65 also has boost control, but it controls boost by venting charged air vs manipulating the flow of exhaust gasses),
        but same system theory. its hard o speculate w/o more E-BOV setups to compare to.



        Click here to enlarge Originally Posted by DFM Click here to enlarge
        heatsoak variances that could raise IAT's and induce detonation.
        Its safe to say any heatsoak will be the worst on a PD compared to the other 2, turbo and centri, so any compensations already made for the PD, would be a limit for a turbo, and overkill, or no?
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Don't try and use logic.
        cant argue if you dont understand the topic.. some of use do, others dont and just post to bump threads and get the last word in
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        but same system theory. its hard o speculate w/o more E-BOV setups to compare to.
        He's not speculating that's exactly how it works it's venting boost.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        cant argue if you dont understand the topic.. some of use do, others dont and just post to bump threads and get the last word in
        I'm scared you honestly believe this but considering how many blatant and basic mistakes you make you may just want to let others discuss it and let Harrop chime in as well.
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        I'm scared you honestly believe this but considering how many blatant and basic mistakes you make you may just want to let others discuss it and let Harrop chime in as well.
        lol, dont worry about me and mistakes i make, they will never compete with you and yours.
        i suppose its easier to tell me im wrongm than prove it... especially when im not.. but ok, let have harrop chime in.

        but before they do, what mistake, where? once again, you HAVE to have the last word.. have you noticed the room clearing out yet?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        lol, dont worry about me and mistakes i make, they will never compete with you and yours.
        Okie dokie but would you mind allowing this thread to be about the discussion of the route Harrop is taking and its technical applications and not you trying to tell the world how much you supposedly know? Please?

        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        but before they do, what mistake, where? once again, you HAVE to have the last word.. have you noticed the room clearing out yet?
        Would you mind quitting your negativity and useless posts once again? This is a really big development if you want to flex your e-ego and what you "know" please do it another thread. Final post on this, thanks.
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Okie dokie but would you mind allowing this thread to be about the discussion of the route Harrop is taking and its technical applications and not you trying to tell the world how much you supposedly know? Please?



        Would you mind quitting your negativity and useless posts once again? This is a really big development if you want to flex your e-ego and what you "know" please do it another thread. Final post on this, thanks.
        the adults are talking about the tuning aspects of a PD and how they compare/contrast to other options, only one poster is derailing it... but its ok because its an administrative privelage
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        the adults are talking about the tuning aspects of a PD and how they compare/contrast to other options, only one poster is derailing it... but its ok because its an administrative privelage
        The adults will continue to discuss this and you are removed from the thread so it can stay on track as you are taking away from a great discussion.
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by LostMarine Click here to enlarge
        there we go, a conversation

        time to full boost. how does the PD and Turbo differ? this is assuming a properly sized turbo to eliminate any lag- considering stock motor s65 cant take any high boost anyway
        we've seen IIRC 2500rpm for the PD. i cant imagine a turbo hitting full boost much after that- (~8 psi)

        we know we are working with a MAX of 9 psi, id say even 8 psi on the PD, and the same with a properly matched turbo, how soon can the S65 spool a Turbo, whats the relationship between spooling a turbo to full boost Vs the centri's Vs the PD, which (given the above) are very very similar

        partial load- given the above-T-spool vs PD boost should be very close no? much MUCH closer than a centri, yes?
        Turbo lag cannot be entirely eliminated without the use of additional anti lag technology. Regardless of how close time to full boost is for each platform, it will always be longer for the turbo (especially in lower RPM's). The computer needs to be able to progressively adjust the timing and fuel as the boost rises at an exponential rate. With a PD blower, boost is similar to an on/off switch, so the progressive adjustment of fuel and timing is more immediate. Where did the 2500rpm for the PD come from? pretty certain a PD blower hits max boost much sooner than 2500 rpm...

        as a function of? CFM? need to know a turbo size, but cant be that big right Click here to enlarge
        As a function of RPM, because the turbo can probably push more air at the higher RPM's than a PD blower at the same boost level. You're right, it depends wholly on the turbo itself. Think of a jet engine. A jet engine is very efficient because the airflow is in one constant direction. Now with a car, we want to emulate this strait through flow as much as possible. A boost adder of any kind will greatly affect the flow of air from air filter to exhaust tips. The differences in the overall flow are extremely different for turbos vs PD blowers. How exactly does this affect the tuning? well, I would think it would only really affect the tuning if you are tuning the cam timing. Cam timing affects scavenging, and scavenging is affected by the airflow through the engine.

        but same system theory. its hard o speculate w/o more E-BOV setups to compare to.
        I disagree that its the same system theory. Turbo setups control boost by modifying the source of energy (exhaust gasses) and how that energy gets turned into boost. This PD blower controls boost by venting it. It has nothing to do with changing what is creating the boost in the first place, therefor the load the supercharger puts on the engine doesn't change, just the pressure in the manifold. Does this actualy affect the tuning? YES. Venting the exhaust gasses reduces the energy going into the turbo, which reduces the speed of the turbo, which modifies the flow volume/velocity of air at the compressor outlet, which lowers the boost in the manifold. Venting charge pressure (PD setup) does just that, vents the charge pressure and reduces boost very quickly. Now I can see how the E-BOV could be controlled similarly to a wastegate, but exactly how you control it is different because the wastegate is the start of a chain reaction in the piping, whereas the E-BOV is nothing of the sort.

        Its safe to say any heatsoak will be the worst on a PD compared to the other 2, turbo and centri, so any compensations already made for the PD, would be a limit for a turbo, and overkill, or no?
        confused on this statement, can you please explain a bit more thoroughly?