Prop riddle sunny vs formula
 

How come my 2004 32 mcob with 6.2 engines, 1:65-1 drives and 24p bravo 1 props struggles to get to 5000 rpm, yet I see 292 Formulas with the same power and drives ect. and they are running 28p bravo's? same top end speed too? what's the difference?

Weren't the 292's twin-step? Probably getting a little more hull out of the water.

Thought the 32's with 6.2's came factory with 3 blade Mirage Plus props?

Ya I called sunsation and they pulled the build sheet, (pretty impressive company and employees-btw), they said mine did ship with 23 Mirage plus props. When I bought it there was 25 Mirage plus props on it brand new. I don't know how the boat could ever run the 25's it took 1/2 a mile to get on plane. If I got aggressive out of the hole with the throttles, the whole boat shuddered,I'm thinking the props were breaking loose.. I put a set of bravo-24's and everything is better, not perfect though. Looking around at other comparable boats with same power I see formulas running 28p bravo stock. I though Formulas were heavy? When I'm wide open I get 4k rpm with more throttle nothing happens, actually feels like the motors lay down at about 4K. I know the Mirage is a smaller Diameter prop but a 23+ isn't gonna get my rpm up, I could be wrong. Trim is maxed out, I could have 12 steps none of which are gonna touch the water. She runs right on the pad.

Stepping down to the 23 will get RPM up. The laying down feeling is an indication your "over propped", the engines just cannot turn the props efficiently. Think of it as choosing a gear too tall in your car or riding a bicycle in too tall a gear for the situation, the extra labor it takes to maintain speed. Also don't compare to another brand with same power, there are many influences that dictate prop choice. Do yourself a favor and call Brett at BBlades, he will get you dialed in

Yes you definitely have the wrong props. But that aside, your point remains and I wonder the same thing.

I have a pair of 23s done by BBlades still in boxes. PM your email if you want pics & info.

Jake

Drive depth is not optimal for 4 blades. Stick with the proper pitch 3 blades and have BBlades tweak to get proper RPM at WOT.

Thank you for all the info. I have a set of 23's coming from Rattlesnake Jake, now I'll have a starting point. Thanks again to all

How's she running?

Well.... been out a couple times, neither of which were ideal conditions. I did see 5200rpm,then over rev alarms, 67ish, too rough to start messing with trim and tabs and throttles. Both engines are running much better with tune ups and new emi exhaust with the short ss risers. With these Mirage plus 23 I still get on plane blow out and cornering.When cruising 35ish it's 3200rpm, I can move the steering about 90 degrees side to side and watch the tach rev as the outside prop breaks loose. Trimming is a no go. I'm gonna throw the 24p bravos back on and see what rpm I can get with those, now that the engines are up to it. Plus the cruise rpm was higher with the bravos too. On a side note new issue. Starboard engine runs great except once in a while between idle and 2500 rpm I get a alarm and engine stall at the same time. Sometimes it won't stall and recovers. Anything over 2500 and up it's fine. Checked wires cables, switches pulled yanked and wont do it on the hose. No codes. Just like loosing electricial power for a split second. Just in gear. ? When I do turn the key, off to on fast, I get the stall but no alarm. Maybe swap ecm and see if it travels. Twins gotta love them! :-)

Check your ground cable on the back of the engine. I chased that one for months and it turned out that the cable was dirty. Needed taken off and cleaned, problem solved. Acted like someone was turning the key off.

I'm curious about 24p Bravos as well. Been blowing out my port engine when running hard. Just labbed my backup set of Mirage Plus 23s, hopefully that does it. If not, going back to trying others.

I had the Bravos on it last year and other than not being able to get more than 4K rpm both engines the props were much better out of the hole, cruise was faster They lifted the whole boat and I could trim them alot more. Everyone says my drives are too deep to use bravos but I like them. 24P should be just about right for me with stock power. You may need 26's with your power. I have a set of new 25P mirage plus. Took forever to get on plane and again couldn't get past 4K but that was due to needing a tune up. I'm setting the boat up for comfortable cruise and holeshot not top end. If I lose 2-3 mph with the Bravos so be it, I won't miss them. As long as I'm not lugging the engines I'm good. Fuel consumption was better with Bravos too, as if that matters.

[ATTACH=CONFIG]541529[/ATTACH]This is running Bravos[ATTACH=CONFIG]541530[/ATTACH]This is running Mirage Plus

Woa. That is NOT how you should be running across the water. Holly bow stuff, batman. That is a trip waiting to happen.

You are seriously trimmed to the moon. The "pad" is your running surface. Look at your angle of attack with the Bravos... The pad is not shaped that way. In reality, hydrodynamics I would think are playing against your favor. You're pushing water and not running on top of it. Makes even more sense why your props are breaking loose.

Sit the boat on trailer. Trim the drives until they are even with the pad. That's where you want to be. Maybe a "tap" of the trim above that.

Seriously, dude, do not run your boat like that. I'm not trying to say I know everything but the last thing I want to see is a fellow boater get hurt. Not to mention a Sunny owner.

I may not be Tres Martin but I have taken his course twice. I think it's something you should look into.

The bravo picture may have been landing. I feel the boat more or rather better control with the bravos, straight ahead and corners. The pictures are just an example of how the props feel to me. Bravos up on top of water and Mirage Plus in the water. Relax- I know how to drive. Here-better?

https://www.youtube.com/watch?v=-E6ocgdr0IU

Before anybody flames me thats our doll barbie that rides up front when we are cruising fast.. She turns heads for sure, topless too!! :drink:

+1 lab the 3 blades. Rule of thumb is about 200 rpm per inch pitch. But if they are labbed it's about 100 if thinned out. But you can also cup the tips and tweet the ends. Just find a good machine shop that works on props. Tell them what is going on and they will know what to do. And if you have twins maybe think about turning in. It looks like it's a bit ass heavy. Just my opinion .

No need to be defensive. You seem to think you know what you're talking about but you're asking for help.

Sticks with the threes and listen to ^^^. Also, you're not running a surfacing drive. They're supposed to be in the water.

Brett at BBlades can work the Mirage props to reduce the blow out coming onto plane and tweak any RPM needs you have. Since top speed is not your concern I would not lab finish the props. Brett did wonders for a buddy running 25" Mirage props having problems similar to yours. Bravos will lift the stern where the Mirages will lift the bow.

At the end of the day, if you like the Bravos better then run them. Just get them tweaked so you are turning the proper RPM at WOT. Good luck.

I hear ya. I'm always looking for info and I am by far not an expert on any of this boating/go fast world. I have 2 burning questions since I bought my 32 last year. #! why does a 32 sunny w/6.2, 1.65 package come with Mirage Plus 23 and the same power package in a 292 formula comes with labbed Mirage 28"s. Is the formula hull that much more efficient? #2 why does 32 sunny sbc use 3 blades and the big blocks use 4 blades? Are the x dim different between the 2? Yes the bravo lifts the stern alot and seems to make the boat run flatter to me anyways. Again thanks for your info.

2 completely different hulls. 292 is a twin step with a notch. 32 Dominator is a conventional hull with a pad. Formula notoriously over-props their boats for top end. Sunsation props their boats for best all around performance.

Run what prop feels best to you for how you boat.

Best of luck finding the props that work best for you! But I wouldn't use that video to make your point... Open water and running at speed with a passenger in the bow?

Reading is fundamental