what propeler for df 150?

[harrisnasos]

Hello every body! I am a new member from greece and i have a df 150 on a 20 foot offshore V hull.
Whith 3x15x21 i have on wot 6350 - 42,5 knots (49 mph) and plane at 2800 - 13 knots (15 mph).
I want lower plane speed and drop the wot rpm to 6000. Thanks (and sorry about my english)

[boats.net]

Drop to a 19 pitch prop, it will improve hole shot and drop rpm's on top end.

[panosz]

Hello every body! I am a new member from greece and i have a df 150 on a 20 foot offshore V hull.
Whith 3x15x21 i have on wot 6350 - 42,5 knots (49 mph) and plane at 2800 - 13 knots (15 mph).
I want lower plane speed and drop the wot rpm to 6000. Thanks (and sorry about my english)

Geia sou patrioti!!!

[harrisnasos]

Geia sou patrioti!!!

Gia sou kai esena, an kai ta leme sto H.R.F.

[harrisnasos]

Drop to a 19 pitch prop, it will improve hole shot and drop rpm's on top end.

Ok about hole shot, but the rpm's on top end will increase and i do not want it!!!

[Tspeck]

I usually figure about 300 -350 RPM per pitch change and it gets me pretty close. ( 1-pitch up = 300 - 350 RPM down, 1-pitch down = 300 - 350 RPM up)
As for your plane speed I would tend to believe that weight and hull design are the greater factors involved.

[sandpiper]

Tspeck,

What you say is true. The higher the pitch the less rpm on top end. I do a lot of reading and mostly what I see listed is that the pitch changes only about 200 rpm. I have called a couple of prop manufactures and they agree on the 200 rpm and some even say 150-200 is a good area to factor when you are looking at changing a pitch of the prop. One thing that I am considering is IF I do change a pitch on my prop I want to make sure I can send the prop back if it does not do the job for me. If you do figure a higher RPM then just make sure you can return the prop and not get stuck with it.