ABC high pitch props

[kfxguy]

Rake is new to me. I don't think Octura even mentions rake in their specs. Would someone explain it to me. I might like to try ABC props soon.

Let's see if I can sum this up for you.

Octura is more or less a "general" or "sporting" type prop compared to abc. Not to say they won't go fast because yea they will. Abc is more targeted at going faster and giving you some "tweaking" choices. Now this is just what I've experienced.
Rake refers to how much the blades are angled to the rear. A higher rake means blades angled closer together which tightens up your thrust cone and creates more bow lift. The new abc props are modeled after full size race propellers.
Here's an example of rake. One is a m645 octura and the angled back one is an abc 1815-17-45

[Mxkid261]

Wow that is quite the difference. So what is the advantage of having more rake? Like in a mono application where stinger/strut adjustment is minimal, but you want more "bow lift" ?

[kfxguy]

Wow that is quite the difference. So what is the advantage of having more rake? Like in a mono application where stinger/strut adjustment is minimal, but you want more "bow lift" ?

More rake would loosen it up and it concentrates the power cone tighter so in theory the forward movement should be great (=little faster) which is what I've experienced. The comparable props between abc and octura, m645 and abc 1815, the abc has proven to be about 6mph faster with less pitch than the m645. And pulled 17 less amps.

[Mxkid261]

Have you ran the abc's on your cats? Might have to try one that is comparable to the m445, I got one like you recommended and boy what a difference it made compared to the CNC prop.

[Jamey]

More rake would loosen it up and it concentrates the power cone tighter so in theory the forward movement should be great (=little faster) which is what I've experienced. The comparable props between abc and octura, m645 and abc 1817, the abc has proven to be about 6mph faster with less pitch than the m645. And pulled 17 less amps.

I think you meant abc 1815

[kfxguy]

Have you ran the abc's on your cats? Might have to try one that is comparable to the m445, I got one like you recommended and boy what a difference it made compared to the CNC prop.

Yes. I think I've mentioned this before. An abc, say 1815 or 1915 slips or cavitates a bit on my mono when taking off. It does not do that on my cat (that I no longer have). Here's a couple videos to compare.

Mono:

Listen to when rpm drops....

http://youtu.be/2w5EXLJuEgs

Cat....

http://youtu.be/GlWajwBlup4

[Jamey]

Have you ran the abc's on your cats? Might have to try one that is comparable to the m445, I got one like you recommended and boy what a difference it made compared to the CNC prop.

I went from a m445 to a 1914 (48mm) and picked up 7+mph on my pursuit. But the more comparable size would be the abc 1814. Both the 1914 and 1814 are the older style 10 degree rake. Can't wait to try one of the new 17s.

[zooma]

I have been having trouble with my P class Pursuit flipping, particularly when crossing another wake. Would higher rake make that better or worse? Also, are these high rake props mostly for SAW or still OK for oval racing?

[kfxguy]

I have been having trouble with my P class Pursuit flipping, particularly when crossing another wake. Would higher rake make that better or worse? Also, are these high rake props mostly for SAW or still OK for oval racing?

I can't say that I would because if you slow down too much it starts cavitating. I guess you could try it tho. If you don't drop below 20 mph you should be ok

[Jamey]

Zooma, i dont race but run oval playing and i think you will be fine but you would just need to try one and see what you think. You are running a m445 now right? The 17 rake props are 1.5 pitch and up so you might need to drop down to a smaller diameter. Maybe test a 1715-17 see how you like it and how the temps are.

[dasboata]

I have been having trouble with my P class Pursuit flipping, particularly when crossing another wake. Would higher rake make that better or worse? Also, are these high rake props mostly for SAW or still OK for oval racing?

Go back to octura or lower your strut to put the bow down !!!

[oscarel]

James, here's the video from yesterday.

https://youtu.be/iO1xicAAY60

https://youtu.be/fmkKmtgJUHo

[srislash]

James, here's the video from yesterday.

https://youtu.be/iO1xicAAY60

https://youtu.be/fmkKmtgJUHo

A little bit of trim tab would go a long way on settling that hull.

[Jamey]

Thanks Oscar!

I have got some room to play with battery position still and I also had a little bit of positive angle on the strut I needed to take out. The batteries were moved forward for the second run. You can tell it helped but not quite enough. I can't really get on it wide open but the very first pass. After that the wakes are just too much for it. The max speed was about 64mph yesterday. By the way after both of those videos my cells were still at 3.93/3.94v . My amp draw has got to be fairly low.

[dmitry100]

dasboata: Are the blades of the ABC props supposed to be alot thicker compared to octura's especially after they have been S/B'ed ?