DDM Supercharger with stock exhaust

    I’ve posted this on the other forum and sent an email to DDM but haven’t heard back...
    I’m not a fan of any of the exhaust systems that are out there..too loud or I’m too old. Also plan on eventually doing the quad wheel conversion so not sure which one would fit anyway.
    I wanted to know what kind of HP numbers I could expect with the DDM supercharger running the Polaris CAI and 1320 headers with stock exhaust?
    Crank and wheel hp.
    How much HP would I be giving up?
    Please show work.
    :P

    Welcome Batman!! Not sure Polaris has a CAI, did you mean stock intake? IMO if you left stock intake and exhaust you'd be giving up quite a bit of HP (especially with added boost) since they are both fairly restrictive. If you peruse prior posts by DDM and others with variously equipped SC Slings you can get a good idea of the effects of different intakes and exhausts. In my personal opinion (less than 2 cents), the least restrictive intake is the Alpha as it relocates the throttle body eliminating the squished bend of most other CAIs. Some good (quiet) exhaust systems would be the Welter or the Alpha variable which is almost as quiet as stock in the closed position but gives you the option of changing the tone with a button push. Basically the stock exhaust is awful in both restrictiveness and heat.
    Good luck with your mods.

    @Bruce Wayne should you decide to get a DDMWORKS supercharger you will not use a typical intake as the air intake Is on the backside of the supercharger and attaches right to it. That comes with the kit.
    I believe that DDM has the horsepower numbers for a stock exhaust manifold, not sure on a stock exhaust. You would have to have a larger pulley to reduce the boost because of the restrictions on the exhaust.

    :BLUESS:
    Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did do.
    ~Mark Twain~

    I’ve pretty much read thru all of the previous posts lol!
    Polaris sells a CAI, I think it’s the one that comes with the SLR. I had them put it on mine.
    I hear some folks had the Alpha’s fail on them. The Welter I like but the stealth might get in the way of a 4 wheel conversion and the dual I’ve heard causes fumes with a tall windshield, I have the nascar style tallboy. But I’ve also got a slingshade and have heard that eliminates fumes. This is a 8k question so you understand my hesitation!

    Quote from Bruce Wayne

    I’ve pretty much read thru all of the previous posts lol!
    Polaris sells a CAI, I think it’s the one that comes with the SLR. I had them put it on mine.
    I hear some folks had the Alpha’s fail on them. The Welter I like but the stealth might get in the way of a 4 wheel conversion and the dual I’ve heard causes fumes with a tall windshield, I have the nascar style tallboy. But I’ve also got a slingshade and have heard that eliminates fumes. This is a 8k question so you understand my hesitation!

    Like I said the intake from Polaris will not be used. Here is a picture of the intake off the back side of the supercharger.

    :BLUESS:
    Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did do.
    ~Mark Twain~

    You will lose your CAI as the supercharger kits have an intercooler which pipes to the throttle body. The stock exhausts fall apart without being boosted. So, that should be enough reason to ditch it right there. The Alpha variable is also not recommended. You need to leave the system wide open or it will have too much back pressure. So, the variable nature is lost once you go supercharged. My Slingshot was on the dyno at DDM with the Alpha Variable in the closed position, then tested in the open position. There was a 25HP difference. Noted that even in the open position there was still a restriction. I would expect the factory exhaust to match up with the variable exhaust in the closed position or worse.

    When life knocks you down, calmly get back up, smile, and very politely say, "Is that all you've got?

    You guys are awesome! Thanks to all for the quick replies! @EjFord you were right about this forum. (Let me know btw whenever you do a ride in the Midwest. I live in Chicago and work near Bloomington/Springfield.)
    Back to my dilemma:
    That is giving up quite a bit of horses from the 280 listed on your site @Dave@DDMWorks
    The Welter dual exhaust with the silencer inserts might be my only solution to keep things flowing but quieter than a fart can.
    What kind of numbers can I expect with 1320 headers and Welter boosted dual exhaust WITH the silencers in place?
    And I can’t seem to find a cat delete pipe? Gains with and without cat delete pipe?

    Quote from Rob the Slob

    Like I said the intake from Polaris will not be used. Here is a picture of the intake off the back side of the supercharger.

    Have seen the DDM SC running on a few Slings at SSITS...The 90 degree rubber cap that goes on the throttle body would inflate like a balloon while under boost. Do they still do that and, if so, has there been any failures on that cap? thx

    Yes on my DDM SC it expands. Dave has instructions on doing a little trimming just above it on the hood to prevent damage.


    Works awesome!!!

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