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  1. #1
    Haven't fallen yet. MJE's Avatar
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    what are the benefits of a setback mod?

    I am just wondering if doing a setback mod does anything aside from "reduce cavitation"...and how much would it really reduce it. Tomorrow and Friday I have to be in NJ on business which means I get to drive near Carl @ island racing. My skis are turning 7190rpms with these dynaflys in them currently and I want to maximize performance.

    what do you guys think? I tried searching but I couldn't find any details on the mod itself and its benefits.

    thanks

    Mike


  2. #2
    injected2stroke's Avatar
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    It will give you better out of the hole performance. Depending on the amount of the set back it will also load the motor harder the closer to the pump the more the load. And you should expect to have your RPM's drop some with this mod. I have a set back on my 03 and I like it but I am only at 7090 with 14/23.

  3. #3
    GPHOTROD's Avatar
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    You didn't say what pitch your impeller was. With the rpms that you list of 7190 and 7120 in your signature, I would not set it back it will lower your rpms. Your rpms should be around 7150-7200.

  4. #4
    philip_gpr's Avatar
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    Skat impellers / pumps which the CC racers use come setback

    I setback all of my impellers - I haven't seen an rpm drop (though others have reported a 30 rpm drop)

    so yes it would be worth stopping by the shop and saying hi to carl

    what rideplates are you using? if R&D or old style Riva and it doesn't have the sides angle up (equivalent to the FF mod) you might get that done as well - Carl has been doing this mod for years - you might leave the skegs as is just get him to do the angle mod

  5. #5
    Haven't fallen yet. MJE's Avatar
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    I already bought two of Carl's mod 4 rideplate along with one of jim's 1300 rideplates. I am considering taking my extra stock riva plate and having him cut it for shits and giggles. I wont be able to make it to Carl's shop because my schedule is going to run much longer than I thought

    I called him on the phone though and hes going to look into fixing the messed up impeller I have...I'm not sure about the set-back mod with the rpm drop everyone talks about...and I honestly dont know how to tell if the impeller is slipping or not during holeshot. I have 3 dynafly 14/20's currently...I think I may have the frigged up impeller done up, repitched and set back while the others I just have him do his magic on the pitch etc. We'll see though..it all depends on what info you guys give me on the positives and negatives of a set-back mod.

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