GPS Measured 330SS Speeds with 496Mags
 

First good day with the boat working well, so we got the GPS going and burned some gas.

Load was full fuel, first mate and I and our long weekend load of clothing, food, etc.

RPM Speed in MPH
3000 33
3200 35
3400 40
3600 42
3800 45
4000 48
4200 50
4400 53
4600 56
4800 58

Top Speed 60.0

Top speed was obtained later as we burned gas down and got lighter. I had to really work it, but we got an honest GPS measured 60 out of the boat.

Fuel Burn
We don't have a fuel flow meter, but we ran from Elk Rapids to Charlevoix and back in total time of just about exactly two hours and varying speeds on the way up measuring with the GPS. About half the way up and back was cruising at 3400 or so. The other half on the way back was wide open to get the all-important 60.

We burned just over 75 gallons in the two hours. I had expected worse!

Cheers!

Sounds like ya'll had a good time.. Your rpms is right at the top on the mags which is good.. what Props are you running??

I would have to guess using 23p? based on 1.5 drives.. that puts you at 13.9% slip at wot and more importantly 18.9% slip @ cruise. both seem high.

if, 22p would be a little better at wot but still not good at cruise... 15.2% cruise and 10% at WOT..

Either way, you can probably gain more mph and better fuel efficiency with a lower slip at cruise with some prop work and/or testing..

I am a lil over propped (with this head anyway) and although its a different boat (yours is wider and heavier), I am getting 9% cruise with 25p m+'s. I also need to get either some the 3 blades worked or try some 4 blades.. (want more on a hi cruise.. ie. 4k as opposed to the family cruise speed at 3400.

I think we are running 23 props, but I'll have to check when we haul out in a few days to be sure. I had the props all reconditioned last fall since they were a bit chewed up when we bought the boat last year.

I'd love a few more MPH at cruise and WOT, but the first mate is balking at the cost for four props!

Thank you for the insight. I'm still on the steep end of the learning curve on this stuff and had hoped someone might be able to share this kind of info!

Cheers

Give BBlades a call and see what their suggestions are. Really nice to work with and will save you a ton on prop testing. They may be able to tweak what you have.

Thanks Cig. I might have to do that!


Now, anyone got any tips on how to convince the family 'Woman Inquiring about Family Expenditures' it is a needed upgrade?

Try this:

The boat will be more fuel efficient and we can go out more often for less money....which is truth, fact and real anyway!!.

I looked at the boat build sheet and it looks like it says 2.0 drives. Would this make more sense rather than the 1.5?