Prop pitch change due to extra load
 

I just had an experience where I had 8 passengers a full tank and enough food for the day on my single engine Velocity 280 and I had a difficult time getting on plane, it took about 10 seconds. I'm running a Bravo 1 30p. I was curious as to what others are seeing from light load to full load performance. I'm almost thinking about keeping 2 props one for my wife and I and another when I have a big group. Please let me know what you are doing.

I know of a 23' Regal Velocity, (same bottom as the 22' Velocity) with a 540 hp/550 ft/lbs 460 that has 3 propellers. Since Steve Stepp likes notched transoms and high X-Dimensions with different weights in the boat it takes a lot longer to plane.

He has a 21/23/25 pitch Mirage Plus props. The 23 is his normal prop, 21 is fully loaded with 6 guys + fuel + food + drinks etc, and the 25 is his "Race Day" prop.

Weight is a huge effect on any motorized vehicle from cars to airplanes.
Boats are highly affected due to drag from wetted surface area.
I use two to three different props or sets of props on my boats depending on the days events. Of course I have a few props laying around to choose from. LOL
I always suggest at least one aditional set for this exact reason. The other reason is to make sure you don't lose a great weekend boating due to propeller damage or failure.

Brett

ThisIsLivin, go down 2-4 inches in pitch for the heavier loads.

Eight people ona 280? Where did you put them?????

I feel claustrophobic just thinking about it!

If you are going to do that often 2 props is a great idea. Even if you don't carry it you could swap out before heading out for the day. Although I try to carry a spare "just in case".

I never have problems getting on plane, but I do lose 6-8mph at WOT going from empty with two people to full with 4 people.

BBlades hit that one dead on. I have twins on my boat and I ran one set when we had a total of 6 in the boat and changed when we went back to the normal wife and I payload. Huge difference.
Good way to torch a motor too. You'll bend valves and all kind of bad things when over loading a motor like that. If it ain't accelerating briskly you need to change something. You'll send a motor into detonation before you can order a set of pistons.
A light weight race boat can get away w/it but our heavy ass pigs can't.

Thanks, trying to get a feel for what is typical. I'll probably run my 28 when I'm loaded and a 32 when I want to go fast and light. Hey Brett, how does labbing effect the holeshot? If I gain 250 rpm on the top end does it look like a smaller prop out of the hole?

Keeping a log each time you go on a run with your boat of prop used, speed at target RPMs, and load would probably would be helpful in determining the correct prop for those applications (I was given this advice by Steve S. of Velocity).
Also I believe it takes a lot of motor to turn a 32" pitch prop on a 1.5 ratio drive......How much HP are we talking about?

Props that I own: 1 - 28" labbed Hydromotive 4 blade, 1 - 28" labbed Mecury Maximus 5 blade, 1- 28" pitch Herring 6 blade, 1 - 29" pitch labbed Hydromotive 5 blade, 1 30" pitch labbed Hydromotive 5 blade. The 28's our left over from prior to installing a Whipple SC. I will probably eventually sell the 28s.

I gues I missed this question a while back.

Yes, the hole shot time frame will increase as well as acceleration. There are tricks to the Lab process to keep the prop hooked up upon acceleration. There are other recipes that allow faster acceleration but can compromise planning ability.

Brett