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  1. #1
    Vern's Avatar
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    Rear Intake - additional mods for more air

    I installed a Riva rear air intake and some other mods over the winter and finally got the ski in the water Memorial weekend. Only had time for a few quick blasts and no updated GPS numbers yet, but I added 1.5 mm back to the 15/20, dropped from an 81.5mm nozzle to an 80mm and I am still pulling 8100 rpms, so I know I gained speed, just not sure how much yet.

    Anyway, I wondered if anyone has done back to back tests with additional mods to the rear air intake area and noticed any additional rpms. With the seat on, there is not a lot of free space around the intake itself ... has anybody cut holes in/modified the rear seat grab handle, or cut the bottom of the seat itself, or done other things to allow more air in, and noticed any rpm increase?


  2. #2
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    Quote Originally Posted by Vern View Post
    I installed a Riva rear air intake and some other mods over the winter and finally got the ski in the water Memorial weekend. Only had time for a few quick blasts and no updated GPS numbers yet, but I added 1.5 mm back to the 15/20, dropped from an 81.5mm nozzle to an 80mm and I am still pulling 8100 rpms, so I know I gained speed, just not sure how much yet.

    Anyway, I wondered if anyone has done back to back tests with additional mods to the rear air intake area and noticed any additional rpms. With the seat on, there is not a lot of free space around the intake itself ... has anybody cut holes in/modified the rear seat grab handle, or cut the bottom of the seat itself, or done other things to allow more air in, and noticed any rpm increase?

    I added a set of Flo-Rites into the grab-handle. No big notice in RPM gain but they do pull alot of air and amplifies the sound of the SC!!

  3. #3

    HOLES

    I drilled one hole in the grab handle and gained about 50-100 rpm

    i am going to add another since my r's have droppes some since the hot weather and mainly the humidity has hit

  4. #4
    Vern's Avatar
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    Thanks for the input. Just had a thought ... duh. I should run back to back, seat on, then seat off and note any rpm difference. Since the rear intake is supposedly only sucking 'outside air', any rpm increase with the seat off would seem to be mostly due to removing restrictions around the filter itself. Hmmm, I will try that this weekend if we get some dry weather ...

  5. #5
    KiwiRXP's Avatar
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    If you ride in salt water with that rear air leave the breather hose in or spray a huge amount of storage oil in there. This is the damage with just two outings in salt water. Both times I flushed and sprayed storage oil in the intake. It sat for 8 weeks like this, couldn't start it becasue it was turning over slowly. SUPERCAHRGER SEIZED. The engine was turning over and the clutch was slipping. That salt will get in anywhere.
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  6. #6
    rior1's Avatar
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    true but you to then have take into account the weight of the seat


    Quote Originally Posted by Vern View Post
    Thanks for the input. Just had a thought ... duh. I should run back to back, seat on, then seat off and note any rpm difference. Since the rear intake is supposedly only sucking 'outside air', any rpm increase with the seat off would seem to be mostly due to removing restrictions around the filter itself. Hmmm, I will try that this weekend if we get some dry weather ...

  7. #7

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    I have numerous holes drilled in that area. Im not really sure if there was an increase in RPMs because I did that prior to my rear intake. I had done it to try to release some of the heat from the engine compartment. Ill try to get you guys a picture of it.

  8. #8
    BMW FTW Yellow04RXP's Avatar
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    will the ski over heat if i run a rear intake without any kind of ventilation on the rear?

  9. #9

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    I dont believe it will overheat but you may be more likely to get a high temp alarm soon when playing around doing 360's and what not. Just get a set of Flo-Rites and install them in the seat cowling just like they are in the Riva kit. I know when Im riding you can feel the heat comming out of them.

  10. #10
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    Quote Originally Posted by KiwiRXP View Post
    If you ride in salt water with that rear air leave the breather hose in or spray a huge amount of storage oil in there. This is the damage with just two outings in salt water. Both times I flushed and sprayed storage oil in the intake. It sat for 8 weeks like this, couldn't start it becasue it was turning over slowly. SUPERCAHRGER SEIZED. The engine was turning over and the clutch was slipping. That salt will get in anywhere.
    U sure your intercooler is not leaking?

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