Tested a M645 and y547, I need help choosing my next prop

[rearwheelin]

The boat I?m using is a 36? Aeromarine avenger cat and weighs 17 lbs. I run it 5-6 minutes on 16,000mah 6s. Been testing and tuning for a few weeks now and like it?s ride attitude the best with the m645 , the larger diameter y547 seems to make the bow light and bounces easier even after moving the CG forward. Boat still turning great with either prop and without gps it?s hard for me to tell which one is faster , I?ve gone back and fourth on which one has the highest speed . I can say it gets on plain better with y547 but the m645 is great too. I do believe the m645 allows the motor to unload better at full speeds according to my ears and video sound and it could be faster by 1-2 mph. What I?m looking for is a faster prop with same diameter as the m645 or a larger prop that?s been cut down some. Me electrics are running nice and cool so I have tons of room to experiment. I?m interested in a 3 blade or 2 blade with more pitch and de tongued . Appreciate your recommendations in advance! My brain has finally started wrapping itself around the prop topic lol

[dasboata]

I can reduce a X645 for you !

[rearwheelin]

I can reduce a X645 for you !

Thank you

[TRUCKPULL]

Your 645 - 1.6 pitch X 45mm Dia.= 72mm of travel per revolution.
Your 547 - 1.5pitch X 47mm Dia. = 70.5mm of travel per revolution.

So lets say that you are running 30,000 RPM loaded, X1.5mm = 45,000mm extra per min. or 750mm per sec. extra travel, or about 30 inches per sec.

Now this is without slippage.

So your X645 prop should be a little faster.

If you are satisfied with your runtime and your temperatures all is good,

Larry

[rearwheelin]

I’m not sure it’s even possible to over heat the mamba xlx calibrated to 220 amps. I’ve tried running the boat as hard as possible and nothing but good temps in hot weather at that. The motor is the only thing gaining heat as expected with around a 50F rise in temp above ambient in 6 minutes of running hard .

[HTVboats]

KV? Motor?

[rearwheelin]

KV? Motor?

TP5650 5y 1150 kv

[HTVboats]

That and the 16000ma explains the 17 lbs. Without knowing your actual speed it is hard to tell much about prop performance. It boils down to what kind of blade area will be efficient to carry the weight. Then run time and speed will be totally opposite. More prop and speed = less run time. I have experience with a 36 Aero and 6 to 10S. If I had your boat I would be running 3 blades in the 44-48mm range for run time and 450/3 and 452/3 for speed. Your run time will go down and your heat will go up as you go faster. no free lunch.
Mic

[rearwheelin]

That and the 16000ma explains the 17 lbs. Without knowing your actual speed it is hard to tell much about prop performance. It boils down to what kind of blade area will be efficient to carry the weight. Then run time and speed will be totally opposite. More prop and speed = less run time. I have experience with a 36 Aero and 6 to 10S. If I had your boat I would be running 3 blades in the 44-48mm range for run time and 450/3 and 452/3 for speed. Your run time will go down and your heat will go up as you go faster. no free lunch.
Mic

I understand no free lunch ! HA HA ! .. The y547 has the best run times and puts the boat on plain best , however the blades are thinned out and I feel like I’m going to bend it when I tighten my prop nut. My m645 is just sharpened and balanced with no real blade thinning done, I like it the best knowing it’s stronger and seems to let the boat ride better at speeds along with the motor sounding unloaded. Definitely a clear difference with them both doing things better in different areas. I definitely want a large 3 blade for speed running . I want to find a good balance of a prop and just increase voltage for any real speed. I think I’m right around 50 mph with M645 , just want a prop that’s a little faster and be able to run a solid 5 minutes . I have 2 great sport props right now , I’m just being cautious with my next prop purchase and looking for that sure thing lol I have videos of the boat running. It’s clear that it likes both props but handles differently in good ways

[rearwheelin]

I’d like to try a x646 3 blade , anyone think that could give me a 5mph boost in speed staying with 6s

[TRUCKPULL]

Randy
If you want a good jump in speed that will not put much more strain on your system get ahold of Dasboata and order a ABC 1619-17 -45 (2) CLL Balanced - Thinned a bit, Sharpened - and Hardened.
Remember also that you will have to adjust your strut a little. Angle the rear of the strut down a little about 2 degrees.
The reason for this is these props have a more concentrated thrust cone, and will tend to lift the bow more then other props.

What I have found for my race boats with these props is that - Speed whent up and AMP draw whent down.

Larry

[HTVboats]

https://www.offshoreelectrics.com/proddetail.php?prod=cnc-4614350

Try one of these. Inexpensive and doesn't need any special work. Anything from 44-50 mm should work well as you have a big torque. We have actually set 2 lap records with these props.
Mic