whats going to happen with a bigger prop with same pitch

[-JR-]

I have a 84 Bayliner 19 ft AQ125 and a 270 leg
Anyways Going from a 14 x17 prop to a 15 X17 ....whats going to happen ? will it go faster ?

 

[Skypirate]

Maybe a little, will depend on torque range of your motor

 

[fhhuber]

Depends on HP and hull and how loaded it is.

More blade area and diameter = more load on the engine for acceleration.
If you have the HP for it, you'll get to speed faster. Depending on drag of the hull you may or may not see a higher top end.

If you are already going close to actual speed = "pitch speed" (pitch X rpm X conversion = mph prop is trying to move the boat) you won't see much if any top end difference.

 

[tpenfield]

Top RPM will probably be less due to the larger amount of water being moved by the prop. I would not expect it to go faster.

 

[Scott Danforth]

If your motor is already not in the recommended RPM range ( lugging ). Then bigger prop may make you slower.

Need to know what RPM and speed you are currently turning at WOT

 

[steelespike]

If you read the stickies at the top of the prop forum and get us your lightly loaded wot(wide open throttle) rpm and gps speed.
we can tell better what will work and what you may need if anything.

 

[jimmbo]

Might have better holeshot, probably lower top speed.