Thread: what's going on
06-06-2009, 02:13 AM #1
what's going on
hey guys I am quite new to the world of skis and have been reading thru this site for a while and am blown away by the wealth of knowledge that xome of you guys have. But having now got fifty hours up on my 08 RXP-X I have decided to start warming it up a little. After testing it with the GPS while stock with the trim set in the middle I got a best of 68.2mph @7840rpm. I installed a 4" air intake and upgraded to the X model A kit supercharger impeller and took it for another ride. Same trim settings and got 70.3mph @8040rpm. quite happy at this stage. Next I swapped out the prop for a three blade skat 14-18 as recommended to me by the guys I got the intake and supercharger wheel from and have gone backwards. With the same trim settings again and same conditions on the water my mph has dropped to 67.4 but the rpm has gone up to 8180-8200. can you please offer me your opinions to what is going on as I am just here scratchin my head
06-06-2009, 02:22 AM #2
A 3 blade prop is usually 2-3 mph slower on top end but has a better holeshot. Have you changed out the intake grate yet. Put an R&D or Worx grate combined with a Solas 15/22 prop (or repitch your original oem prop) set up to run 8060-8100 rpms. Bet you see 73-74 mph easily.
06-06-2009, 02:42 AM #3
Thanks for that. I am ordering the r&d grate next week and am going to tweak the stock blade. what's with only shooting for 8100rpm. if the stock limiter comes in at 8300rpm why not aim for closer to it like 8200 or 8250.
06-06-2009, 02:59 AM #4
The "X" boats have a hard limiter at 8200 rpm. The ecu pulls fuel and timing well before that. Best power is at 8000. I have mine pitched to run at 8040-8060. I've read that the engine loses 4 horsepower between 8000 and 8200. You risk a lean condition running close to 8200 rpm. You can always have your ecu reprogrammed by Les Cooke for 8400 rpm. Let us know what your speeds are with the new grate and repitched prop. I have 1 oem prop set up for cold weather with a pitch of 14/24. I've seen 72.6 on my T-X running that prop. My other oem prop is pitched for hot weather at 12/22. Haven't gps'd it yet but I think it will run 70. Getting ready to install the 4" kanaflex and will have to repitch again.
07-01-2009, 02:30 AM #5
I have put the stock prop back in for now. filled the ride plate holes and did the reverse bucket mod and got to 71.4@8060 which is a bit over a 1mph gain from previous best with this prop.
Just finished putting worx grate on this evening and will test it in the morning.
I have sent my three blade away to get repitched as i had a go myself and could not budge the blade at all. Mustn't have had enough wheaties for breakfast or something.
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