NicoG

Hello Guys.

Right then, as promised.....

With High-Five, 38 knots GPS @4,600rpm WOT.
2-up with half a tank of fuel in 2 foot chop...

Didn't play with trim too much as the sea state was a but choppy to really guage the effects of that.

Unfortunately, we weren't able to test the Mirage, as the delivery Guy failed to see the notice on the card he left the day before, asking him to leave it with a neighbour....

Anyway, we're happy to see the revs rise to roughly where I would expect for this engine, but weren't able to verify with another Tach as I didn't have access to one at short notice...

Does ~ 45mph seems reasonable with a High Five in that sea state?

Thanks - Nick.

Crude Intentions

iTrader: (1)

Trimming will definitely add mph. With drive in your plowing and not getting hull up. Those numbers assuming 1.5 on the drive give you a 21% slip. You can certainly get that down. Changing nothing else but getting slip down to say 12% would give you 54ish. All sounds about right just gotta play with props now.

NicoG

Thanks - that's good to hear.

How do I actually get slip down though? by trimming the drive up?
How far out should the drive be? The indicator is broken so it's difficult to know how far out is is apart from "how many seconds" I hold the switch down for!!

How far down should the tabs be to compensate? Appreciate this will cost top speed.....

4mulafastech

When it is not too rough out go wide open and just start bumping the trim up a little at a time while watching your speed. You should feel the hull start to free up (with the right prop) and the speed increase. Prop slip will also go down since the hull is not plowing causing additional drag. You will find when you trim too high the speed no longer increases and rpm just goes up (increased slip). After some seat time you will get the feel for it.

Crude Intentions

iTrader: (1)

4mula is correct. It's truly feel. It will also change from prop to prop you try. Also different props will have varying degrees of slip. But trim up until she starts letting go then back her down. Also if boat starts porpoising its trimmed to high.

CAEMI

I hate to be ignorant so, ahhh, maybe you could help. I just bought a 206 LS and want to pick up a spare/new prop. Can't tell what is on it. What should I be looking at...a Mirage 14.5 x 21?.

What difference would it make to, say, install a 14 x 22? I don't understand the impact of diameter versus pitch. Can you point me to some knowledge online? I hate to bother people on the forum with rookie questions.

Mr Maine

What engine do you have? 350mag?

As pitch and diameter go up, rpms come down. Higher pitch will be faster for the same rpm. There is a lot of info on how props work if you do a search.

If you have a 350mag, 270 horse, then you want to spin it to 4600 to 4800 rpm. A 21 mirage plus should be close and is a good prop for that hull.

CAEMI

Ok. I understand - thank you. I hate to ask a stupid question...but what diameter would that 21 mirage be?? 14.5?

The previous owner said he GPS'ed speed at 54 on the dot. He also said the with "my aunt and uncle in the back seat, beer in the cooler, and full fuel, I can't get it to plane without trim tabs". That said, aunt and uncle weighed about 450 between the two of them.

I'm satisfied with that speed. I understand it isn't reasonable to expect much more out of that power/hull combo.

Again...thank you for responding. I do appreciate the help.

CAEMI

BTW, I have been reading up. What I cannot seem to find is what the probable effect of a 15.5x19 versus a 14.5x21 in the same wheel might be. Also, I read quite a bit about how some props elevate the boat more than others, sometimes so much so they get light at the transom and wander, etc.

As i mentioned...54 is respectable and I'd be pretty happy with that. Just trying to learn more.

CAEMI

I forgot to mention - yes, 350 Mag, Alpha one, reported to be 270 HP and stock throughout.

The hour meter reads 730 but I suspect the key was left on. Boat does not show that kind of use. I'm estimating more like 300 but could be wrong...might just have been very well cared-for.