OJ 948 vs. Acme 2313

[teamerickson]

Got out on the lake today and put the 2773 through it's paces. I'm very happy with this prop. Top speed ended up the same as my 1615, about 41+ mph. My rpms dropped about 200 to 300 while surfing. At 11.2, full stock ballast, PNP, 600 lbs bow triangle, and wedge in third position from bottom, we were turning 3100 to 3200. This same setup would have been 3400 to 3500 rpm on my 1615. Most importantly, my LS3 didn't even break a sweat surfing. There was lots of power in reserve and the boat just seemed to be running smoother. To be fair, I never hit a wall on my 1615, but the engine did seem to be working harder with that prop while surfing.

I'm wondering if the greater slippage of the smaller 14.5" prop causes more turbulence off the prop, which is picked up by the power wedge and translates into a rougher ride???

I'm a believer in the 15" props now. You just need to select the right pitch for what you desire. My past experience with the 2315 has told me I won't be happy with the top speed of a 12 pitch prop. The 2773 (15" x 13 pitch x 0.105 cup) seems to hit my sweet spot.

Oh man! I guess I need to flip my 1615.

Edited July 31, 2015 by teamerickson

[Cory]

Cory, thanks for the update!! Just goes to show that the SG surf wave causes quite a bit more drag than listed waves. We were surfing really loaded up (all my ballast full, probably 3000 lbs, plus crew of 6) last weekend at 11.2 mph with my 1273 prop. Motor was turning 2900-3000 when I was 3 clicks up from the bottom on the wedge. So, for me, the 14.5" props are "good enough" and my backup 1615 will be just fine at altitude.

The SG waves are WAY less efficient wave makers than listing.

[gorilla]

The SG waves are WAY less efficient wave makers than listing.

I thought so and now you've really proved that. I'm not a big fan of listing my boat to surf because novice drivers can't control it well. So, the wifey has learned how to drive the boat weighted and does a damn good job keeping from dipping the front or taking waves over the back. For now, gonna keep the '07 and keep foiling and surfing behind it.

[Cory]

Oh man! I guess I need to flip my 1615.

Ya, since the 2773 achieves the same top speed with more torque, it really does seem like a better option. It would seem this is too good to be true, but I guess the increase in torque is coming from the increased efficiency from the larger diameter. If there are any downsides, I would note: 1) if you hit an underwater stump, there is less clearance (safety margin) before your prop hits the gel coat if you bend the strut/shaft, and 2) there may be increased prop torque. I'm not certain about 2). I didn't notice any additional roll. Perhaps the lower rpms of the 15" prop while surfing offsets any increase in prop torque due to its size???

[Cory]

2773 performance on my 22VLX with my wife and I and two very small children:

3000 rpm: 23 mph

3500 rpm: 28 mph

4000 rpm: 32 mph

WOT 5500 rpm: 41+mph