Change Gears or Props???
 

Trying to figure out if it will be better to change gear ratio from 1.35 to 1.5 and go with a larger pitch prop. Or leave 1.35 and go with a smaller pitch prop.

I was seeing which one would be better for the engine conf and if slip numbers generally get better or worse with a lower or higher pitch.

Thanks

Several very high power boat owners seem to favor either the 1.5 or 1.62 gears. I'm by no means on ya'lls level, but the gear ratio seems to be a better (if more expensive) option

The 1.35's are easier on the drive with a smaller pitch prop but we always end up going back to the 1.50 and bigger prop for the speed.

A prop person on this site said a good starting point on props is twice the diameter of the prop is a good pitch to run. e.g. 15 5/8" prop w/32 pitch. My boat gets on plane way better with lesser pitched props but I have to run my 1.5:1 lower with a 35P because of coin. Hopefully next year I'll get some 1.36:1 lowers and 32P props for my birthday. I'd love the data comparison.
The only thing I ever hear is that the 1.5's are stronger.
Anyone else do this swap? What'd you gain/loose out of it?

1.36's are actually stronger than 1.5's apparently.

I would leave the 1.35's. I don't think you will see any big differences and you won't have to worry about running prop pitch.
A 1.35 change to a 1.5 is usually about a 3" pitch difference.

+1 especially with a cat. In my mind, 1.5:1 is standard gearing on a V and 1:3whatever is a good cat starting point. Unless your speeds are under 80 (guessing thats not the case with any skater...) I wouldn't entertain the 1:5 unless you have motors that really need to rev.

What motors r u running , r u hitting the rev limiters , what size props ?

Its on a 32 Skater. Ilmor V-10s. No6's. I changed cams in the engines again and they are making good power up top. The boat pulls like a freight train after about 85mph. Runs good to 120 but then feels like it hits a wall. I have 1.35's in the drive and am turining the props in. They are 16.5 x 35 Merc 4 Blade. Its only turning them 5500rpm @ 120. The cam change and valve train that i have will handle 6500. That is where i set the rev limiters. I just feel like if I change to the 1.5's like Peter at Skater suggested, and run the 35's i think it will get the engines up a little higher in there peak hp.

Here lies the problem. If you go to a 1.5 you will run out prop. The biggest four blade is a 34. You will need to go to five blade prop that the 32 Skater does not like. Been there done that. I did the gear changes on my 32 and I should have stayed with the 1.24. I have a set of 16.5 x 32 four blades I can sell you for $1500. MINT props. Way cheaper than gears changes.

U could go either way , what's cheaper , I assume the prop change would be . You should give brett @ bblades a call , he might suggest reworkin those 35s like takin a little diameter off . #6 drives seems like alot of overkill for that setup

Economically speaking, a prop rework would be the cheapest. A different set of down pitched props would be a more expensive option. If you look at going with gears a prop change is most likely going to have to happen also...which would add to cost even more. You might want to talk to Zastrow and see if he will let you test his props for a fee. Or get BBlades involved to test some wheels.

If you have a smart phone download the propeller calculator...fun to play with and it may help you.