150Hp Gain in under 2 hours

    We had a great time here on Friday, a bunch of folks showed up for a dyno day and also a Rotrex install. It was really nice to meet @Sling Cat and have the chance to install a Rotrex supercharger on his Slingshot. We thought it would be fun to time an install this time since we haven't timed any of the installs in the past. We started by running his Slingshot on the dyno and getting 3 nice dyno pulls for a pre-install reference, then pulled his Slingshot around to start the install at 11:15am. We fired it up for the first time at 1:00pm, just under 2 hours later. After doing a couple runs up and down the road to make sure everything was good, we put it back on the dyno and did some post install pulls. The install came out great and the new power was a nice bump over what he had.


    DDMWorks Slingshot Rotrex Supercharger Kit


    Starting the day off right with some doughnuts - thanks @MACAWS




    This is what we started with, an intake, header and exhaust.



    Installation of our custom intercooler for the Slingshot Rotrex kit with shrouding, upper and lower mounts -



    The compact Rotrex unit and mounting plate installed, ready for the charge tubes to go on -



    Things are starting to come together -



    Charge tubes installed, fuel rail installed with Siemens 63# injectors and 2 bar MAP sensor -



    All complete and out for some testing -



    Back on the dyno for some post install dyno runs -



    Making some pretty good numbers on the dyno -



    Final results, pretty fun little ride with just a couple hours of work -



    DDMWorks Slingshot Rotrex Supercharger Kit

    Those HP numbers put a smile on my face... wow!!! AND in under 2hr install THATS just magnificent!!!!





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    And if you notice the stock SS dyno pull you can see that Dave's dyno is calibrated to read about 40hp low. That is when @MACAWS called me in a panic.... He was all upset because his Hahn dynoed at 220hp.. I immediately started thinking "my new engine is going to show less than when I started the engine project." :)


    On the same loaded setting my pulled 431hp. So even if I have to use that as my HP rating I can add the 40hp on the table to it. So that would make it a 471hp pull.


    Dave u need to claim that extra 30 to 40 HP. Your supercharger is putting out 300hp at least....

    Quote from lrobbi

    Those HP numbers put a smile on my face... wow!!! AND in under 2hr install THATS just magnificent!!!!

    Not just in under 2 hours but a flawless - neat - clean install. Like I said in another post I am anal when I work so I have great admiration for people who work the same way. You can tell the moment you walk into their facility that they take great pride in their work place and their work.


    And the great Dyno numbers are a benefit as well.


    But the real secret is to feed them doughnuts with sprinkles early in the day!

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    Sorry but I'm confused. If stock is around 170hp shouldn't the pull show a greater number than 118hp - stock even had a CAI which I would think would be good for a couple hp - I know I'm missing something basic here so I appreciate your understanding and education

    Quote from Ross

    Sorry but I'm confused. If stock is around 170hp shouldn't the pull show a greater number than 118hp - stock even had a CAI which I would think would be good for a couple hp - I know I'm missing something basic here so I appreciate your understanding and education

    Most companies are using a Dynojet dyno, which typically reads higher than our dyno. The dynojet dyno's are just a big metal drum that is spun up for the dyno reading. The dyno we use has 2 drums, but the main difference is that it has an eddy current load cell and we dyno with that on. The load cell puts a load on the engine and drivetrain and pulls the HP and torque numbers down lower than typically most people will see on other dyno's. So for us, that number for a stock engine is pretty typical, but on other dyno's people typically see around 150-160hp.

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    @Ross that was what I was referring to in my post above. He has his dyno calibrated to show a lower number. Basically he uses the dyno as a tool to benchmark improvement. But once you know how much the difference is between it and what we are used to seeing you can just add the difference. I have dynoed my Hahn 2X so many times that I can quote the rating in my sleep.

    That is also why I wanted to be clear and honest when I posted my graphs. I posted the loaded numbers. And the 431hp was based on the same dyno numbers with a stock SS making 119hp. So whatever you want to add to 431hp to make up the difference is what mine did on a loaded dyno.


    Anyway you do the math I am happy with the number.

    Quote from MiM

    So.... Out the door price?


    I know I basically need about another $17k to have my wish list... Paint, speed, and wheels/tires... That's it!

    $4900 for the kit in standard black or red, $5000 for it installed here at our shop with a pre and post dyno.


    Here is a link to the Rotrex Supercharger kit - DDMWorks Slingshot Rotrex Supercharger Kit


    It is also for sale through Slingmods now - Polaris Slingshot Supercharger Kit by DDMWorks


    We can tune it to run on a stock exhaust, the 1320 exhaust and header or the Welter duals right now, although any good 2.5" exhaust will work.


    Let me know if there is anything else I can answer for you about it.

    Quote from Ross

    Now I get it thanks guys I was looking at it too quick thinking more apples to apples than it was .... still kick ass gains but that stock number made my heart hurt a little until I understood


    That's what I said. I was on my way there and everyone started to panic when they saw the first numbers pop up.. :):) It didn't take long for my phone to ring
    .....


    I was worried mine would show less than 300 when @MACAWS called me