prop for Echelon 350 MPI 290 hp

[Woodshed]

My stock prop at 13 x 13 pulls decent and gets me 47mph. It's a Dymex Mr. Minus.

I dinged the prop and am currently running a friends spare Acme 13 x 12. I love it's better whole shot but i lost top end. I didn't want to push it too hard but at 4800 rpm i only got 41mph.

Most of my use is slalom course for me and the guys. I'm learning to barefoot this Summer. The rest is kids stuff.

So am I gaining anything getting a new cnc prop and if so what do I want for my uses? What will i lose and gain as far as whole shot, top end, and slalom wake? Should I continue with the OEM Mr Minus 13x13?

Thanks

[Woodski]

That sounds odd to only get 41 mph @ 4800 rpm, I would check the Acme part number to see exactly what it is. You should be able to install a 515 or similar and get excellent results. For the disciplines you mention, a 3 blade CNC prop correctly sized (either Acme or OJ) will provide excellent results and should get you very close to the 100 rpm for 1 mph ratio. What was the rpm @ 34 or 36 mph?

[JasonK]

I'd say stick with MrMinus unless you want to trade top speed for holeshot. Wish my boat did 47. I only get 40, but i't's a 23 y.o. prop. Time for me to upgrade.

[Woodshed]

drove it again paying attention to the rpm's. It's pretty close to 1:1.

@ 30 3080 rpm

@ 34 3450 rpm

@ 40 4100 rpm

I got 44 at 4700 rpm and then backed off I suppose if I ran it harder i'd eek out a few more mph's. But I just feel like I'm pushing it so hard.

I think I'm losing a few on the top end. I'm fixing the stock prop and will put it back on until I figure this out.

[JB-FOOT]

When you say you are getting 47 mph, what is your reference for speed? Speedometer or GPS?

Speedometer is not always accurate unless it has been calibrated on a given day...

Are you on a Lake or on a River?

If a river, what was the current speed, and were you testing with or against the current?

Are you at Sea Level or at what ELEVATION?

Was your boat full of people?

.....how many?

Was the boat full of Fuel?

.....how much?

What year is your boat?

What motor is in your boat and what is the recommended RPM range that is notated on your motor?

4200-4600, 4200-4800, 4400-5000 RPM??? Etc?

When Dialing in a prop, and I do mean truly dialing in a prop, you need to consider all of these factors...

And then you say you want to start barefooting later this year...if that is the case, have one of your buddies that KNOWS how to barefoot evaluate your wake crossing and curl when you are trying out the new props, and make sure he/she compares them on his/her bare feet to your "repaired" Mr. Minus prop for a baseline comparison....

Once you answer these questions, we can help you MUCH better based on your facts not our guesses.....

Edited July 10, 2013 by JB-FOOT

[Woodshed]

When you say you are getting 47 mph, what is your reference for speed? Speedometer or GPS?

Speedometer is not always accurate unless it has been calibrated on a given day...

Are you on a Lake or on a River?

If a river, what was the current speed, and were you testing with or against the current?

Are you at Sea Level or at what ELEVATION?

Was your boat full of people?

.....how many?

Was the boat full of Fuel?

.....how much?

What year is your boat?

What motor is in your boat and what is the recommended RPM range that is notated on your motor?

4200-4600, 4200-4800, 4400-5000 RPM??? Etc?

When Dialing in a prop, and I do mean truly dialing in a prop, you need to consider all of these factors...

And then you say you want to start barefooting later this year...if that is the case, have one of your buddies that KNOWS how to barefoot evaluate your wake crossing and curl when you are trying out the new props, and make sure he/she compares them on his/her bare feet to your "repaired" Mr. Minus prop for a baseline comparison....

Once you answer these questions, we can help you MUCH better based on your facts not our guesses.....

JB-Foot Ok... thanks

I'm not sure the rpm WOT range at this point. But I have a 1996 Echelon LX Mercruiser 350L MPI 290 HP

I have Stargazer so that's my GPS speed. 637' elevation, on a lake, I was the only person, I got 44 at 4700 rpm but up to 40 I was close to 1:1. I forgot to add and consider that I had a bimini up that I would think was a big drag factor. (embarrassed I didn't consider that!)

I've only had one barefooter behind my boat before my prop interests started, so we had no conversation about it. I'm around many here, so I will ask them as I go forward.

[JB-FOOT]

JB-Foot Ok... thanks

I'm not sure the rpm WOT range at this point. But I have a 1996 Echelon LX Mercruiser 350L MPI 290 HP

I have Stargazer so that's my GPS speed. 637' elevation, on a lake, I was the only person, I got 44 at 4700 rpm but up to 40 I was close to 1:1. I forgot to add and consider that I had a bimini up that I would think was a big drag factor. (embarrassed I didn't consider that!)

I've only had one barefooter behind my boat before my prop interests started, so we had no conversation about it. I'm around many here, so I will ask them as I go forward.

Good to know you have REAL speed via GPS

you are about the same elevation as me, so this I can relate to...

We constantly foot behind a 94 Closed Bow, 95 Open Bow & 97 Echelon Closed Bow....so I KNOW that your wake CAN be good, but individual props feel DIFFERENT under your feet and at different line lengths and speed that you foot at...as all of those factors change the shape and feel and placement of the rooster tail and table of the wake....

Our 94 and 95 both have big blocks in them and our 97 has the Monsoon 320hp in it....so the only prop we can really relate to is on the 97....I don't know what we have on that one exactly, but my guess is an OJ 13x13 3 blade....

I am a fan of 3 blade props for skiing and footing and an even bigger fan of Acme over OJ, although I own both....for different boats and applications..

Our 97 Echelon turns 5050 rpms and runs 47.5 mph maxed out...

[Woodski]

44 mph @ 4700 rpm for a 290 hp Echelon is reasonable for the described condition. Bimini will make a very big difference, it is a lot of drag. Drop the bimini, check with: 1. center window open/closed. 2. spark arrestor on/off. 3. steering wheel centered and going straight/ hands off and going where it wants too (if safe to do). Rudder torque (item 3) will have an effect on top speed. Temperature and humidity will also have a significant effect on top speed, so checking in hot weather will result in a slower top speed. Is your hull reasonable clean, if not, time to clean it. As noted many things affect top speed including air and water temperature (and condition), boat weight and balance, add on items like bimini's and towers.

I found alternate props to the Dymex provided a 2 mph boost in top speed, that one seemed to hit a wall at the top end. I went to a CVP which was better and now use an Acme that works well. The CVP props have a tendency to sling a blade on occasion as it appears they crack at the blade to hub weld over time.

Awesome on the learning to barefoot aspect, have fun and as noted, get some good advice on it. A good driver is a huge asset when learning the sport particularly for deep water starts and advanced tricks.