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Thread: Performance upgrades

  1. #1
    Join Date
    Nov 2016
    Location
    Union Michigan
    Posts
    102
    Boat
    2014 RZR

    Performance upgrades

    I have the 350 hp 5.7. Basically a GM small block that’s been marinized. Has any body tried any performance improvements such as cam swap, head work?

  2. #2
    Join Date
    Aug 2010
    Location
    Long Beach, CA
    Age
    42
    Posts
    1,007
    Boat
    1999 2100i
    If it's efi, you're in for some money if you want anything more than stock HP out of it ($10k+) and those gains are minimal, less than 400hp. The cams are ground to a specific horsepower profile which will require a computer (ECM) reflash if you change it. Basically you're asking for trouble on a towboat if you want to add more HP. The marine engines (pre LS) were not designed to maintain the HP of their automotive counterparts due to continuous duty load factors.
    Fixing everyone elses boat just so I can use mine...

  3. #3
    Join Date
    Mar 2004
    Location
    San Clemente, CA
    Age
    52
    Posts
    3,836
    Boat
    1997 2150
    Changing he prop to fit your needs is probably easier and cheaper.
    Mike Allen, Tigé owner since 1997

  4. #4
    Join Date
    Aug 2015
    Location
    Salt Lake City, Utah
    Posts
    874
    Boat
    2013 MB F24, 2000 21V
    I'm looking into adding a supercharger to mine this spring....if I keep it. The biggest problem I am running into is finding someone that can tune Indmars proprietary ECM. If yours is PCM it may be easier or harder. I have not found anything to suggest that any GM engine was modified from its original intended use (the auto world) other than maybe the oil pan, exhaust, cooling additions and sometimes intake changes. I know for a fact that my L96 is a stock truck motor with exhaust and a tune. That makes it a perfect candidate for an LSA supercharger. It would of course have to be tuned. If I cannot find someone to tune it then I would have to swap the ECM to something that tunable. This isn't a big deal either, but I haven't been able to figure out if Zero Off will still work with the new ECM. Worst case is I would have to change out the throttle system to a cable and run Hydrophase. I know my way around LS engines very well so this isn't a difficult task. I would save a lot by doing the install myself. I figure it will cost about $6k on the high side and $4200 on the low side. What the option fee for a raptor supercharger or even the older LSA optioned motors? $12k-17k?


    A prop change works great up to a point. Unfortunately to do what we do at our elevation, it required a prop that runs the engine at 4500 surfing and over 5000 cruising at a SLOW 22 mph.
    Last edited by UNSTUCK; 01-17-2018 at 01:37 PM.

  5. #5
    Join Date
    Nov 2016
    Location
    Union Michigan
    Posts
    102
    Boat
    2014 RZR
    Mine is an Indmar also. It seems to be impossible to find information on them. I figured tuning the ECM would be the biggest hurdle. Please keep me informed what you find out. I agree about props, I have been completing a lot of prop tests for my employer and the results are not what people think. But that’s for another thread.

  6. #6
    Join Date
    May 2014
    Location
    Vancouver Island, BC, Canada
    Posts
    735
    Boat
    2014 R20 with taps 3
    What prop are you running?

  7. #7
    Join Date
    Jul 2015
    Location
    Orange County
    Posts
    1,302
    Boat
    2018 Rzx3
    I have tested countless props on almost every current Tige engine/trans package. The correct prop for what you are intending is absolutely critical in performance, and can be drastic. Keep in mind, their are countless props with countless combos. Knowing exactly what each element does and controls is essential. You can spend hundreds of hours messing around with props that wont do you a bit of good because you are not even at a decent baseline with diameter/pitch and cup.

  8. #8
    Join Date
    Feb 2016
    Location
    Boise, ID
    Posts
    526
    My question would also be how much weight are you running in your 20ft RZR that weighs less that 4k lbs?? Tige put that same Indmar 5.7 in RZ2 and in Z3s in that same period of time, cant recall for sure but think `14 was the first year that was the switch from PCM to Indmar. I have run both here at 3000 ft with lots of weight and had no problems. 1235 is a good all around here with weight and that motor and if you wanted to run heavy we would run the 2079. My thought process would be why do you need more out of said motor?

  9. #9
    Join Date
    May 2014
    Location
    Vancouver Island, BC, Canada
    Posts
    735
    Boat
    2014 R20 with taps 3
    Unless you’re at crazy elevation, the 335 is more than enough. We are at sea level, acme 1433, weighted evenly with taps 3, upwards of 3k in ballast and no problems what so ever. At times we wished we had the 1235 for a little more power.

  10. #10
    Join Date
    Nov 2016
    Location
    Union Michigan
    Posts
    102
    Boat
    2014 RZR
    I have the stock Acme 1631. I know another prop will shift power around the rpm band, but there is not a problem more power won’t fix. Actually I don’t have any problems, I love the boat it does everything I want it too. I just like to build engines.

  11. #11
    Join Date
    Feb 2016
    Location
    Boise, ID
    Posts
    526
    Well there are plenty of bolt on mods for the 5.7 out there but as mentioned you will run into ECM tuning issues. If you have Diacom you can change CAL files but as far as I remember from my indmar training there isn't really drastically different tunes for that engine. Each one was manufacturer specific and some manufacturer didn't run knock sensors so the tune is a little "safer" in that in runs fat fuel and retarded timing to keep it safe. Your Tige should have the knock sensors and in turn have the more aggressive tune.
    So short of dropping a 6.0 in it I don't think you would get very far with bolt on mods, without doing what unstuck is talking about doing for ECM

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