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  1. #1
    Orlando Shark's Avatar
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    Boosting a 4Tec NA Motor BOOM!

    Boom is what everyone is saying that’s going to happen. It’s very likely to happen and we will all find out at my expense. Either way I have another motor on deck with CP pistons, molnar Rods, etc. Since it’s been so long that I havenīt played around with a 4tec motor, I wanted to do this build and if I end up messing something up, well, it won’t be on the expensive motor .

    So i’ve Been out of the forums for almost 5+ years or so and got the itch to ride again. Don’t know that much about the newer skis with the fancy ibr and all that so decided to get something 06-08. I mean, it sounds great but I just see something else that could break. I ended up finding a 2008 GTX hull that had sponsons and UMI Steering. Was missing mostly everything else. I ended up picking up a 2007 Gtx at auction for cheap which I thought of just swapping everything over to the 2008. So, what I didn’t realize was that the Gtx had a 155 motor instead of a 215. Oh well, let’s make lemonade out of lemons!

    My goal: I just want it to turn on Ideally, I’d want to hit 80 with an x charger. I will be running e85 which in theory, should cool my combustion down and eliminate knock(This is what destroys the 155 pistons)

    Heres a list of what I have so far:

    Stock 155 pistons/Rings
    Stock Rods/ARP bolts
    215/255 Flywheel/Aftermarket 10.9 bolts torqued to 32ft lbs
    Starter bendix from a 255
    2008 255 pto with oil jet
    Arp Head studs torqued to 100ft lbs
    Supertech Springs/Retainers
    Shaved head
    X charger
    9500 tuned ecu with 80lb Injectors
    Aeromotive rrfpr
    PLX Wideband
    4” intercooler
    08+ waterbox(will be shortening and gutting)
    riva rear exhaust
    Opas delete
    Walbro fuel pump

    Hope you enjoy, this should end with a big smile on my face or lots of carnage.
    Last edited by Shark; 04-07-2018 at 03:20 PM.


  2. #2
    Keep us update

  3. #3
    Orlando Shark's Avatar
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  4. #4
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    just DOO it............BINGO DINGO!!!!!!!!!!

  5. #5
    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by Shark View Post
    ... Don’t know that much about the newer skis with the fancy ibr and all that so decided to get something 06-08. I mean, it sounds great but I just see something else that could break. I ended up finding a 2008 GTX hull
    ...

    Opas delete

    ...
    There have been significant advancements in the hull designs over the intervening years. The 2018 ST hull is receiving lots of praise, and some of the other recent year Seadoo hulls are also well regarded.

    Other than OPAS, the list you posted is all about the engine.

    We each choose and focus on the things that seem important, but one thing that cannot (for the most part) be significantly changed is how the hull is shaped and how it handles. Seadoo also has some interesting upper deck designs, such as the narrowed ergolock seat for cornering.

    Is the 2008 hull a really good choice for the conditions you expect to ride in? And the speeds you hope to attain?

  6. #6
    Is that a typo 8.9 flywheel bolts?

  7. +1 by:


  8. #7
    Orlando Shark's Avatar
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    Quote Originally Posted by RXP6 View Post
    Is that a typo 8.9 flywheel bolts?
    10.9, Typo

  9. +1 by:


  10. #8
    Orlando Shark's Avatar
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    Quote Originally Posted by K447 View Post
    There have been significant advancements in the hull designs over the intervening years. The 2018 ST hull is receiving lots of praise, and some of the other recent year Seadoo hulls are also well regarded.

    Other than OPAS, the list you posted is all about the engine.

    We each choose and focus on the things that seem important, but one thing that cannot (for the most part) be significantly changed is how the hull is shaped and how it handles. Seadoo also has some interesting upper deck designs, such as the narrowed ergolock seat for cornering.

    Is the 2008 hull a really good choice for the conditions you expect to ride in? And the speeds you hope to attain?

    I agree, new hulls are designed much better. My next ski might be a 300 rxtx or might go to the dark side and try out an FZR. Not sure what my speed goals are at the moment, I know once I hit 80, I will ikely want to go 90, and then 100, etc. The only thing stopping me is the misses, I told her this was going to be a stock ski...nothing too fast...lol....

  11. #9
    I wish you luck. Hope she holds together.

    Screw the new hulls it's easy to make something new fast but to take something old and make it fast that is much more fun.
    Plus all these new hulls look at the oldies and when we smoke em lol.... sleeper style


  12. #10
    Orlando Shark's Avatar
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    Got the supertech valve springs/retainers in. Spun the motor via the supercharger so whichever piston I was doing would be at tdc so my valve wouldn’t drop down into the piston.

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