Page 1 of 4 1 2 3 ... LastLast
Results 1 to 10 of 35
  1. #1

    Join Date
    Jan 2007
    Location
    Lakeland, FL
    Posts
    1,414

    '07 Speedster 150 4" Air Intake

    Somewhat dissappointed in the results. I THINK it has better throttle response now (but I also THINK my car is faster after washing it), and I might have gained 100 RPMs (hovers close to 8100), but strangely, it did absolutely nothing for my top end. Stock, in 70 degree weather, it was a solid 57mph boat (GPS), but in 85 degrees, I'm running 56mph, and the intake did nothing to help that.

    I first tried to connect the 90 degree silicone tube with SS filter directly to the SC, but it just wasn't going to happen, so I found at Home Depot, a gutter drainage tube, of all things, that had 4" ends, and probably more in the middle. I will just continue to learn as others do it, and see if what I have needs improvement somewhere.

    FYI, the SS filter is very important. I've already cleaned off many large objects (bugs, fiberglass, etc.) that were caught on the outside of it.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	4 inch intake 1.JPG 
Views:	676 
Size:	1.12 MB 
ID:	19952   Click image for larger version. 

Name:	4 inch intake 2.JPG 
Views:	2000 
Size:	1.43 MB 
ID:	19953  


  2. #2
    EZ Dock of Long Island Shibby1485's Avatar
    Join Date
    May 2005
    Location
    Long Island, NY
    Posts
    9,464
    +1
    4
    http://www.greenhulk.net/gallery/sho...500/ppuser/769

    try something like that... something with a SMOOTH interior to the intake. that stuff is terribly corregated and greatly disturbing airflow and creating turbulance.

    get the intake away from being looped thru the exhaust pipe, that's heating up the intake hose.

    you know the vents on the sides of the engine compartment? .... they have the black hoses draped down into the hull there as vents? get some 3 or 4 inch bilge fans that suck outside cold air and push it into the hull... those boat hulls are pretty sealed up, so you aren't gettin much cool air circulation thru there

  3. #3

    air mod

    i would have to agree that the drain pipe is not doing much good. smooth surface inside will keep airflow moving correclty. If the 4" won't fit on the sc, reconnect the stock air hose and disconnect on the other end where it splices to the stock intake. this will move your 4" filter over to the side of the bay away from the heat and put it close to where the cool air comes in from the vents. A rigid 4" to 3" reducer them cam be added to the hose and your 4" filter will bolt up.

    let me know if this helps.
    Last edited by bayouboy; 03-28-2007 at 10:49 AM. Reason: incorrect spelling

  4. #4
    cyoungesq's Avatar
    Join Date
    Apr 2006
    Location
    Bridgeport, CT
    Posts
    217
    "Somewhat dissappointed in the results. I THINK it has better throttle response now (but I also THINK my car is faster after washing it), and I might have gained 100 RPMs (hovers close to 8100), but strangely, it did absolutely nothing for my top end. Stock, in 70 degree weather, it was a solid 57mph boat (GPS), but in 85 degrees, I'm running 56mph, and the intake did nothing to help that."

    If your tach is reading 8100, then your top end limitations are imposed by the rev limiter and not necessarily by air intake restrictions. To truly reap the benefits of newfound horsepower, looks like you'll need a prop with more pitch.

    That hose from home depo looks pretty flimsy . . . the air flow/suction created by the s/c can actually collapse a non-rigid hose. You're better off not using the stock "elbow" for the s/c intake because it's not smooth and it extends the 2 1/2 " diameter intake by about a foot. Your best and easiest option is to grab a 4" adapter and attach a 4" 90 degree elbow like the pics of somefun's set-up.

  5. #5

    Join Date
    Jan 2007
    Location
    Lakeland, FL
    Posts
    1,414
    I'll be getting a new prop, but I'd still pitch it to be at 8100rpms. I'm not hitting the rev limiter (at 8200), so the revs are where they should be.

    The Home Depot hose is a lot stronger than it looks, but is anything but smooth. According the fluid dynamics, smooth is not always more efficient, but I imagine this tube is creating some negative internal vortices nevertheless. I am not using the stock SC elbow, in the second picture you see I've placed a cap on that. I do have a 4" 90 degree elbow attached to the filter (first picture), but I couldn't get it all to fit down there. I believe the ticket will be using a six inch long piece of 4" PVC onto the 90 degree elbow, like somefun did, to get the filter to stick up higher and away from the exhaust. Engine heat will still be a problem though; I think it would only hurt performance if I added enough pipe and elbows to reach the vents.

    If I gain more performance using the smooth PVC, at least this would have been a test of what doesn't work well. It is curious that I gained max RPMs, but not top speed, which leads me to believe I'm getting more air in the supercharger, but much hotter air.

  6. #6
    you definitly need to get smoother piping in there.. That stuff defeats the whole purpose of adding an intake..


    Im sure there has to be someone else with this setup that can give you a better description of what you need to make this work!

  7. #7
    cyoungesq's Avatar
    Join Date
    Apr 2006
    Location
    Bridgeport, CT
    Posts
    217
    If you could just clamp this on your supercharger intake flange, it would be perfect!

  8. #8
    How about bolting that 90 to the supercharger (pointing up) and then adding about 6-8 inches of 4" PCV pipe..

  9. #9

    Join Date
    Jan 2007
    Location
    Lakeland, FL
    Posts
    1,414

    Problem solved

    I put the stock intake back on, and was surprised how sluggish it felt. Accelleration was slower and top speed was 55 @ 7900rpms (FL heat).

    Then, I put on my new intake, and oh what a difference. Accelleration is blistering and I'm spinning 8100rpms. Only went up +1 on the top speed, but we'll see if I can get another 1-2mph out of a new prop. I'm thinking a S.C. 13/18 should be about right.

    I got the idea from somebody here to use a "Y" connector to keep the stock intake connected also.

    Thank you, for everyone's input.

    -Scott
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	4 inch intake out.JPG 
Views:	560 
Size:	1.08 MB 
ID:	20222   Click image for larger version. 

Name:	4 inch intake in.JPG 
Views:	843 
Size:	1.55 MB 
ID:	20223  

  10. #10
    That looks WAY better... and solves the issue with relocating the rectifier..

    But i wonder if it would make slightly more power with just having one tube..

Page 1 of 4 1 2 3 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 07 Speedster 150 215HP $14,000 OBO
    By NCRXP in forum Sea Doo Sport Boats
    Replies: 7
    Last Post: 07-19-2008, 11:24 PM
  2. New Guy - '07 Speedster 150 155hp
    By burninoneup in forum Sea Doo Sport Boats
    Replies: 2
    Last Post: 06-28-2007, 07:16 PM
  3. '07 Speedster 150 215 HP in shop already
    By mali907 in forum Sea Doo Sport Boats
    Replies: 5
    Last Post: 06-24-2007, 10:34 PM
  4. Getting 07 Speedster 150 155hp
    By nofd843 in forum Sea Doo Sport Boats
    Replies: 2
    Last Post: 06-15-2007, 02:53 AM
  5. New '07 Speedster 150 SCIC
    By VX1 in forum Sea Doo Sport Boats
    Replies: 22
    Last Post: 03-04-2007, 11:02 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •