Gentlemen,

I have chaparral 2850 sx with twin 350s (carbed). I have 21p stainless props on there now hit WOT no prob. That being the case, can I possibly try and run 24 pitch props on there and get a tad more top end speed or just leave it as it is. Perfect conditions I’m runnin mid to upper 50s. Boat with fuel and people around 6500lbs, motors are stock.

Respectfully,
Andrew

What RPM is your WOT??

3 inches in pitch will reduce your WOT rpms by about 600 with the same make of prop.

4,700-4,800 sir

That,s about right. Mire pitch will drop the rpm.

Sometimes certain boats really like a certain model of prop. And the answer to that is to find others (power of internet) with your exact model boat with same power and drives, who have played around with props.

There’s a guy that has a 29’ chris craft stinger with the exact same power and drive set up runnin 24s on his and he claims 65mph....inwanted to reach out to sone pros and get an educated opinion

Is a 29 Chris Craft Stinger the same boat as your 285o SX Chaparral ?

way more to props than pitch. Different model props with same pitch may make your boat horrible to drive or great or …..

So, yeh, i afree, maybe some prop pros have some experience with your exact year/model/engine/drive boat and know what’s best. That would be great , of course.

Oh I’m sure there is I don’t know much about props to be honest, figured I’d just throw it out there. The stinger is pretty close to comparison. It’s actually a heavier boat obviously due to size difference by a foot and some change. Maybe I’ll find a place that’ll let me experiment with some. Just figured I’d reach out here and see what’s what. I appreciate your time

Short answer is no. You will turn it into a pig with 24" props considering your current rpm with 21" props. You might want to try some 4 blades with less pitch for different performance, like hole shot and mid range cruise efficiencies, but you likely won't go any faster.

You are right about where you should be.

Id think 24p is going to kill the rpm,.................. that guys boat is never as fast as he says when you're on it......