Help choosing new prop

[Imback31]

I have an 07 Doral 190 with a 4.3 merc carb rated at 190HP. I would like to upgrade the prop to a stainless steel one, I would also like to get out of the water quicker and plane at lwer speed, (have trouble keeping on plane when pulling the kids on the tube at 20mph). Any suggestions? I am clueless on what is on there now, any help figuring that out too would be great.

 

[Marv]

Re: Help choosing new prop

4blade w/1" pitch higher than currently on there.

 

[Tail_Gunner]

Re: Help choosing new prop

4blade w/1" pitch higher than currently on there.

you mean lower....

But much more info is needed Speed and rpm @ wide open throttle would help but for a shot gun appraoch a 18p 4 blade ss. try apollo they have a exchange program

 

[Imback31]

Re: Help choosing new prop

when you say lower that means if it is 20 got to a 19? How do I find the pitch that is on there now? (I never drive it WOT, no need, so does this matter?).

 

[Imback31]

Re: Help choosing new prop

you mean lower....

But much more info is needed Speed and rpm @ wide open throttle would help but for a shot gun appraoch a 18p 4 blade ss. try apollo they have a exchange program

do they exchange to canadian customers?

 

[Tail_Gunner]

Re: Help choosing new prop

when you say lower that means if it is 20 got to a 19? How do I find the pitch that is on there now? (I never drive it WOT, no need, so does this matter?).

Yes although YOU do not dive at WOT...it is a bench mark to arrive at a fianl gearing ratio.....Boats have one final gear unlike cars...You take a boat to its top rpm band with a prop...and hopefully it's linear that is the right gear for all rpm's and you engine will respone in top fashion to the tourqe being applied....

3 blades will give you top speed's 4 blades will give you lower planning speed's aka more tourqe and lift..3 blades drag less than 4 blades but 4 blades have more push...surface area at the same rpm...at very high speed the 4 blade does have more total surface area creating drag...while a 3 blade has less..aka the 1-3 mph speed gain