30P 4-BLADE vs 32P 6-BLADES
 

I am currently running 30p Hydromotvie 30p intimidator IV X props. Performance is ok, top speed is no problem, but they do blow out at 2200-2500rpms if I give it more than half throttle out of the hole.. I have twin 800+ SC motors XR's and -2 lowers in a single step 32' fountain.

Would 32p 15.5" 6 blade herings be a good fit for my application? I beat up one of my current props and need to replace, so was thinking of trying the 6-blades

Pluses and minuses?

Thank you!

The more blades, the harder on the drives. Think you talked me about my props on swap shop. On a stock xr with that kind of power I think I'd stick with the 4 blade and just go up in pitch if it was me

unless you are way over your recommend RPM range with the 4 blade 30's, 6 blade 32's will not work. If you want to try 6 blades you need 28's. But yes 5 or 6 blade props will hook up better

I had been asking about this before... being that they have more blades, does that change the needed pitch? I am not really worried about turning them, I believe I have plenty of motor.. but can you explain this a little further if it's not too much trouble?

More blades will reduce slip a couple percent so maybe the equivalent of maybe 1 pitch. Cup can also effect the overall pitch so it's hard to put a definite # on props. If you're running 800s with 1.5 ratio drives on that small of a boat I would think you could spin way more than a 30. Heck I turn 28s with power to spare with single digit slip #s in a lot bigger boat. Call b blades. I'm sure he can point you in the right direction

No doubt I can spin a much bigger prop.. I just dont want to give up the out of the hole performance, but also want to reduce the Slip!

Ok now you are running 30's, what is your max RPM? lets say its 6000 and you have the throttle wide open. If your engine is designed to run at that RPM and makes peak power close to there than you are using all of the engines power. If at 6000 RPM you are at ¾ throttle then you are way underpropped and can go bigger.

I always do it this way, engine builder says ideal max RPM is 5600-6000, there is a rev limiter set at 6150. In cold air with the perfect water conditions, nobody on the boat but you, no gear, running on fumes you should be just barely on the limiter at full throttled ideal trim with the boat aired out. That way when you have full fuel, coolers, summer heat, 6 people on board, you are still in that 5600-6000 range and not lugging the motor.

You haven't really given us any info on the motor or RPMs, also blowing out at 2200 rpms is not a big deal unless you spend a lot of time there, as long as you can get on plane without problems. Also with 800 HP motors and XR's you probably shouldn't be using full throttle to get on plane even if the props stay hooked up. :)

I honestly have not topped the boat out to see if I can hi the rev limiter or not. They are buillt 500efi's with Whipple chargers. They make about 830hp. I do not full throttle it out of the hole, maybe half throttle if that, and it will blow them out... which makes it hard to get on plane. actually does better with more weight in it.. more people and fuel.

So from what I gather, Just stay with a good 4-blade and be done with it? I really don't want to destroy the drives, and Obviously Top end isnt an issue since I've havent seen it yet any way! The boat is new to me as you might have gathered, and its tucked away for the lovely winter.

I guess if it ain't broke dont fix it applies here.. The only variable is I do not know if the current 30p props I have have been worked or not... They look like they have been worked, so I dont want to buy just one to replace my damaged one.

You need some seat time first to figure out how the boat runs then start messing with props. The ones you have may be perfect but props are cheap, great way to improve the performance. Does't hurt to try some others and see if they are better or worse than what you have.

Why do you have to give more than half throttle, if it gets out of the hole and on plane without trying to hammer it, I'd say your good. Not a drag boat, throttle down once your going on plane.

Bigger props are for only if you can't get it up on plane, there is always some cavitation trying to get the hull up and over on plane. Some some less / some more, no slip ,it breaks.

My 2 cents.