I/O Prop Pitch ???

I know most of you here have V-drive boats but I'm needing some input on prop pitch. I'v got a 2015 Mercruiser Bravo One 5.7 350 Mag on a 23' Glastron. The prop that came on the boat is an aluminum "J 14 x 23P" which means pitch is 23 right? Top speed is about 55mph with 2 people & a full tank which is great and even with 8 people I top out close to 50mph. When towing wakeboarder or even with a boat load of people it takes longer than I would like to get on plane. I am willing to sacrifice some of the top end to get on plane quicker but how much lower pitch should I be considering??

boat & engine weight 3360 lbs.
rider weight +- 1200 lbs.

Thanks for the help in advance.

I had a 20' Crownline, about same weight as your boat, same engine, same drive and I believe I was using a 19 pitch stainless prop. The best bet is if your dealer will let you try props, mine loaned me two at a time (plus the one the boat came with) and I tried all three and stuck with the original one.

I do have a Vortex 14.5" x 19P on Craigslist for $40. I'd sell it for $30 + shipping as I moved to a Sanger V210 and it is just taking up space in the garage. I had this one as a backup one so the only wear and tear is paint scratches from bring in the boat. It has never been on the boat.

A stainless is going to perform a bit better than a aluminum as well.

I would agree with going stainless if you change props. They are more efficient.
For hole shot on a boat like yours there are several things that will help other than the prop. Adding trim tabs has numerous benefits. Bennett hydraulic ones work really well but you can get electric or other brands. Many people like 'SmartTabs" which operate without manual control. They work well, except for wake boarding. There are many benefits to the Bennett tabs other than just the hole shot and if you get them, you will enjoy having them.
Putting on a 'vented' prop can help the bottom end without hurting top speed. Usually you can set the vent size to give you the right amount of extra slip coming out of the hole. On mine I used the covering plug and just drilled a hole in it getting slightly bigger until I had the correct slip. It allows the engine RPM to be in a high torque range when you are starting out.

To get the correct pitch you need to know the RPM you are running at speeds, especially top end. When you drop pitch to 21" or 19" you pick up torque multiplication for better acceleration but run the risk of over revving the engine. That's easy to cure by simply backing off the throttle if you are near the redline, but you do have to pay attention. Dropping pitch will not normally hurt fuel use at a cruising speed and will improve it on starts and wakeboard speeds. A four blade prop is probably good but you could try a five.

Generally speaking, every inch is a 200 RPM change. So going from a 23" to a 21" is 400 more RPM at WOT, or a 19" 800 more RPM at WOT. Going from 3 to 4 blade is worth about an inch of pitch, so a 23" 3 blade to a 19" 4 blade would be about 600 RPM higher at WOT.

Ideally try to keep the WOT RPM at the redline engine RPM. Evaluate current WOT RPM and MPH. Evaluate current RPM at your riding speed. You want to be in the meat of the engine's torque range at riding MPH to be able to hold speed easier and more consistently. Pitch low enough for an acceptable hole shot at your typical weight. once you have your numbers, compare potential props by using a prop slip calculator and RPM calculator. Personally, without knowing exactly how your boat currently performs but having previously had a 21' SBC powered I/O, I'd go with a 19" 4 blade and see how it does.

I'll have to check my RPM's and MPH this weekend.

One more question I've been told aluminum props are more durable than stainless props and stainless will just break if you hit something in the water. Now it's not like I ride around looking for logs to run over but **** happens. So is the added performance of a stainless worth the added cost over an aluminum and is the likelihood of breaking a stainless prop so small it shouldn't even be a factor here?

Thanks for all the info. very helpful

A lot of peeps forger about the drive ratio on i/o boats as they vary a lot more than Inboards so a 19 maybe a good fit for one brand but not so much for another this will also effect rpm/pitch ratio Stainless is more durable than alloy but if you hit something will more likely break as alloy is soft and will fold over this also means you may end up with a more expensive repair if you hit something hard with stainless as you will more likely damage the driveline but if you have underwater insurance it prob won't make any difference to you

I always ran aluminum props as I'd rather have a bent prop than be rebuilding my outdrive and replacing hard parts. Cheaper to try a few and find what works best too. Unless you are making serious torque (i.e. not a small block) I don't think stainless is the best use for the additional money.

Aluminum props do fail quicker than a stainless and it matters what your water conditions are like. If there are branches, pieces of wood or a sandy bottom you might hit a stainless prop will last much better and cost less over time. If you are hitting rocks an aluminum prop gets beat up but can be fixed easier than stainless and runs less risk of damaging the drive unit. Do you know your water and are careful of where you boat? Talk to others who have wrecked props where you boat and see what they think. That's direct experience that may give you more confidence than an opinion like mine.