I bought a boat that came with a bravo1 mercury labbed 29P in the box,is this a true 29P prop p/n 48-831916L55
I'm assuming it was a 28P which was technically a 27.3P approx. and then they made it nearly 1.7 more pitch when labbed finished.

Is it really it really 28.3P or 29P ???

(Thought they only changed approx. 1 pitch either way on stainless props?)

Not sure how they get labbed at mercury, if i buy a Bravo1 30P am i getting the same thing (29P)? If i go to a Hydro what do i get?

Trying to figure out my actual prop slip, for my next prop purchase and drive height.

Thanks

If you switch to a hydro and want the rpms to remain close to the same, then go with 1" less pitch for the Hydro.

The part number you listed shows it as 15.25" 28 RH on www.mercruiserparts.com.

The amount of cup that is added or removed can make the prop perform different. For example I have a Mirage plus prop, progresive pitch dropped to 24p, then a double cup added. So it works more like a 25p, I get more bow lift and less slip. Here is a prop calc that I like to use. http://www.rbbi.com/folders/prop/propcalc.htm

Most performance props are progressive pitch, today. That means the pitch increases as one moves from leading to trailing edge. What's on the box is the "effective pitch" or what the prop seems to behave like.

Jeffswav is right. Cup makes a big difference. So does rake angle, but that's fixed by the design. The only way to know is to try -- but an expert can shorten the learning time.

The guy to ask is Scott Reichow at Merc Racing. 920-921-5330. He runs the prop dept and can answer your questions on what they do. He's helped me a lot.