What Prop size should I look at?
 

Got the boat working right for the first time in a long time.

So like anyone would do I stretched her legs. Well in doing so twice I punched the limiter and sent and overspend code. Once in the rough stuff and once on the inner coastal flats. Either way the boat is way under propped. It hits the limiters with a lot left to spare. With tabs and trim it will still climb but still reaches the max well before I am out of throttle

Oddly I am not exactly sure of my current size as I never really looked at them. It is a all factory 2005 Sonic 358 with Brice 1's, 496 Mag HO's, and 4 blades (guessing 24 or 26).

What sizes should I look at or try? I was leaning to a 30 but some input would be nice.

From Monday

Sonic 358: http://youtu.be/CDc6peEmhWI


Sonic 358: http://youtu.be/ENDxW9CSPHo

Need to verify drive ratio (should be 1.50:1) and current prop pitch. 30's are most likely too big. Labbed 28's might be the ticket but again need to verify what you currently have.

I wish you had that info on hand, kind of sad I don't know it off hand.

Some pics are the best I got at the moment for a rough judgment.

http://i57.tinypic.com/dlhqfa.jpg

http://i59.tinypic.com/2wggmqd.jpg

I know we are running different power but the same hull...... I would 1st find out exactly what you are running now, and if they were ever labbed or worked. Then I'd call the guys at BBlades. They have been very helpful in the past with my boat. Now from my experience with my 358, I was very happy with my 4 blades, top end and cruise worked well for me....... then 2 years ago I had an issue with my insurance company and needed to shave a few mph to keep them happy. I called BBlades and they advised me to go to 5 blade props and change the pitch. They nailed it with the 1st props they sent me. My speed was right were I wanted it to be and to my surprise my hull loved the 5 blades. I called them to ask if it was possible that it handled rough water better with the 5 blades and there answer was yes, which it noticebly did. My cruise speed was also improved. I know I didn't give you any specific answer but just thought i'd share my experience with the same hull.... good luck and keep us posted.........

I had a buddy look at them and no one thinks these have been touched. Just factory blades is the thought.

I would like to add just a touch to top end but really a little more cruise speed would be what I am really after.

Boat saw a best of 69mph on the river. In the ocean we got to 65mph jumping out of the water when it hit over speed.

In a prect world a low 70 with a high 50's cruise would be perfect.

I think those numbers are very doable..... I'd give Brett a call for sure......

Sweet.

I wanted to make sure my dreams were not too far fetched.

Call Brett at BBlades he's great to work with.

You might want to try prop rotation as well. Just put them on rotating in, And go throw the shifters in reverse to test it real quick. You may like it better who knows.

I'm running 28s on my 32 Advantage w/496 HOs. It had 26s when I got her and I too was hitting the rev limiter. I can hit 5100 on a cool day and would like to try some 30s, but not sure enough to drop the dough. 5000 gets me at or a little over 80. I'd say you need 26s at least, and possibly 28s.

Most likely 26's or possibly labbed 28's.
Use BBlades test program.

Nate,
Are your props Bravo1's? If yes, the pitch of the props are the last (2) digits cast into the prop hub on the outside...
Dean

Imo 30 is too tall... I'd bet you'll be at a 26 5 blade or 28 labbed bravo one.

In all my prop testing adventures I have found that my boat hates hydromotive stuff. Brett or Ryan (I believe) at bblades are top notch... I ran 7 or 8 props through them this spring before I found what my boat liked.

Also make sure you know the drive ratio because assuming a 1.5 when you really have a 1.36 is enough of a difference to screw up your figuring.

Also slip is a huge factor. Getting below 10% (I've recorded as low as 7)

Happy testing.

Yes, they are for sure Bravo 1.

I will look at those digits when at the boat this week. Thank you Dean!!

Just a quick observation but if you don't extend the bunks on you trailer your current props will be the correct ones before too long..........

Ya good point

Boat is sitting back on the bunks in that pic.

Someone stole my crank handle so I just used a pair of vice grips to crank the boat on. Didn't quite have the leverage I wished with some hand held grips.

The trailer and bunks fit the boat good when I have something to actually crank the boat all the way up.

Normal
http://i60.tinypic.com/w8symx.jpg

Now that's funny! I've had a lot of things stolen at the ramp but never my winch handle! LOL
Back to the prop question: Get the prop pinch and run the slip numbers and see where they fall.
You're probably close enough on you current props to send them to BBlades for some tweaking......

Ya...people are A-holes. Last time someone hit my trailer and took a light out, this week it is my crank handle, what can you do lol.

Ya I am going to give BBlades a ring for sure. See if I can get it all done before the end of the FL season.

Nate the awesome fl boating season just around the corner, fall.....

Nate.. Call me after 8 PM tonight. The Sonic and the Avanti are virtually identical hulls and I had a 2002 Avanti 33 with 496's. With the 496 HO's I got around 76-78 MPH. With the 08 hull and 525's I get mid to upper 80's with labbed props. I have a few sets you can test if you wish. 28 labbed 28 STNRD and a set of labbed 30's. I had a set of labbed 32's but it was a bit too much under normal use. I could only spin them to WOT if the boat was light, me alone.. lol and med chops to get air. My first guess is a labbed set of 28's YOu can try mine if you wish. Plus, spin your props in. That hull needs a little bow lift. Brat is awesome fixing things.
PS.. BTW.. don't feel alone, I had my cranks stolen once too.

Ya I loved it last year in Nov area. Nice in the 70's with sun. Makes for fun days on the water for sure.

Hell we had a Christmas boat ride last year and loved it.

Is that true ? Does this hull like them spinning in ? I do notice my bow likes to stay low.....

In short .. "yes" .. Do a little search on the Avanti, Banana racing hulls and Sonics. Charlie Mac designed the Banana boat, A bit later, Jean Cloud Simon designed a different deck and were racing under the Coyote Beep Beep fame. Same hulls. Then the molds were sold to Sonic, and Avanti, (not sure who got them first off hand) but the hull pretty much remained the same with deck mods. Check your strakes. 5" 4" and 3" (back, toward stern, than you can see you got an "original" Banana hull. ) I had Charlie on my boat several years ago and he also suggested to spin the props in. It does work better.

I've done more prop testing on my old sonic than I'd care to admit .
The boat is 1-2 mph faster spinning in but it rides very loose and as everyone knows the docking is terrible!!!!!
Right now your prop shaft height is between 6-7 inches below the bottom of the boat which will give a bravo 4 blade prop approx 12% slip on that boat. I believe the WOT of a 496 HO is 5200 rpm. I seriously doubt that you will turn a 30" or even a 28" prop to 5200 with that power. If you are able to turn a 26" bravo prop you'll have a top speed of 73 mph.

Wouldn't spinning in lift the stern? If the boat likes bow lift, Brett at Bblades has a Bravo I 4 blade receipe for Bajas that would probably work well on the Sonic.

Rev limitier should be at 5150 on an HO. WOT RPM range is 4,600 - 5,000 RPM.

Is the docking really that much worse ? I feel like I should give it a shot to see how it feels with more bow lift........

and Nate, sorry for hijacking the thread......but i think it's all good info being shared here.......

I hardly notice ANY difference with the docking issue. However, you can always just use one motor/drive. Boats with singles dock just fine all the time.... don't they? :)

Docking a twin engine boat on only 1 engine is not even remotely close to a single engine boat. A single engine boat is in the center not pushing from 1 side only. Also how many 36' boats do you see with a single? The boat rides like a bag of **** with the props turning in. It's not a stepped bottom boat which usually benifits from turning in. I put $100,000 into a 35 sonic trying to get it to run fast. Learn from others MISTAKES lol
I'm not saying it's not worth a try to spin in because it's easy to do and doesn't cost anything to try.

I don' have much to help with prop size but I can chime in on the whole docking with props spinning in.. I have a 30 Concept that spins props out. It has pretty good dock manners. I tried spinning them in a few months ago. At first I swapped the lower units and forgot to switch the shift cables. I tried to take it out that way, however when I came back, even though I knew the shifters were backward, my arm wanted to do the opposite of my brain which made docking tuff. So if you do try to just swap props and leave the lowers alone, make sure you have a wide open space to dock. On to actual performance.... My Concept did respond a bit better to the props spinning in, it gave me a few more MPH on top end, however my cruise economy did seem to suffer a bit. Also docking while not difficult, it was a different monster. Basically had to steer it instead of leaving the steering neutral and using throttle to swing it around. It was easier to use just the starboard motor to dock...

After I switched back to spinning out is where things got ugly. It was then that I crashed into a dock, because I was so used to docking spinning in that I throttle up the wrong motor when spinning the boat around..... Ooops......

By all means go for it i enjoy reading it all.

Ya I am not trying to make a rockets ship here. I know this is a heavy boat with mild power.

I would be super happy with a top around 73 like you said and a cruise speed in the mid to upper 50 area. I think I want to try a 26 first and go from there.

I do think the limiter was 5200 iirc from this Sunday.