Reply With QuoteWe have about 550 to 600 HP in my moms hydro with one of shelfo 11-16 3 blade props ( Witch works great) and it runs about 7200(22 gear) to 7700 (15 gear) and is 97-103mph in the 1/4. I would say put a smaller prop on it.
What gears are you runing?
15,s
We have about 550 to 600 HP in my moms hydro with one of shelfo 11-16 3 blade props ( Witch works great) and it runs about 7200(22 gear) to 7700 (15 gear) and is 97-103mph in the 1/4. I would say put a smaller prop on it.
23.4% slip, I would try some other prop, see if some one a CFW has a prop that you can try. I feel you could get you prop slippage down to around 15 to 20% if you get to 20% you will pick up 5 mph. 18% and your 98 mph. Just my .02$ If I can help let me know. Thanks j.j.
23.4% slip, I would try some other prop, see if some one a CFW has a prop that you can try. I feel you could get you prop slippage down to around 15 to 20% if you get to 20% you will pick up 5 mph. 18% and your 98 mph. Just my .02$ If I can help let me know. Thanks j.j.
I have no prop slippage now it bites right now and the bow is in the air [look at picture below] and I'm not stabbing it to the floor, I want to get my rpms down and my top end up at the end [looking to get to 110mph] and trying to save my motor, do you think 18s would work better??
HI RICH. i like the idea of agear change. ill be at PC and glad to help!! #530 633 9055 ANDY.
Are you guys talking about putah creek at berryessa when you say pc???
The gears change is only going to make it bite more and will slow you down. The prop spin will give you more rpm down low but not up top. Also your motor needs more power to get to110 mph. 6500 rpms are not a lot. Motor should live a long life.
Anyone have a set I need to move up in gears I'm pushing to many rpms 6500 to get at 93.5 on basically a stock motor, and I know a person at cfw that knows how to change them if he shows up at pcr. Rhino??
Shoot... rich, I'd enjoy giving you a hand with a gear change,
but I am already committed to another boat-outing. I have to fly all the
way up to Anchorage to get a ride. I heard this boat is bad-a$$, it has 3
or 4 pissed off deisels in it, and once you commit you can't get out for 10 days or so.
Naw, just messen, have to go on a little cruise, leave the 4th return the
17th. I know I'm gonna miss a good trip w/ you guys, we'll git-er-done
next time.
Have fun, be safe.....Matt
I have no prop slippage now it bites right now and the bow is in the air [look at picture below] and I'm not stabbing it to the floor, I want to get my rpms down and my top end up at the end [looking to get to 110mph] and trying to save my motor, do you think 18s would work better??
Sorry all boats have prop slipage, just because you bite well enough to carry the nose and accelerate hard does not mean your prop isn't slipping. A prop in the water is not like tires on pavement even the best pro racers have prop slipage just ask them.
if your turning 6500rpm with 15's and 15p prop no slip is 106.3mph so 93.5mph is 12.1% slip
if your turning 6500rpm with 15's and 16p prop no slip is 113.4mph so 93.5mph is 17.6% slip
the formula is: engine rpm x gear ratio /(1056/prop pitch) = theoritical mph
Give me a call 972-438-2277 . Like Carnivalride said all props slip. If your prop was not slipping your speed would be 120.33 mph. 6500rpm X 1.15 [gear] X 17'' [ pitch of prop ] x 60 [minutes in a hour] divided by 12 [ inches per foot] divided by 5280 [ feet per mile] = mph with no slip. I think your gears are ok but your prop is slipping to much. But if you can try a set of 18's try them. But if you can pull them to your 6500 rpm you will only pick up 3 mph. If you car lower your slippage 5% you pick up 5 mph. Now your up to .04$ thanks j.j. :idea:
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