blackhawk drive and props
10-12-2015, 07:22 PM
#1
blackhawk drive and props
so I have a 18 donzi classic with a 350 mpi and supercharged pushing 500hp. I am running 85 mph with my 27 but I was wondering I have 2 sets o 27 one set of 29 and 31 can I run 31/27 or 31/29 herd it is hard on the gears. can I get more out of my set up or should I leave well enough alone.Also im planning to put a padded bottom on this winter.
10-13-2015, 08:07 AM
#4
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Based on those numbers I think you are very close to best performance. I would not recommend running different pitch props because it loads the lower gears, and that is after the torque is multiplied by the upper. You would be better served by working the matching set of props. Those props are usually fairly thick and the area of the blade is kind of large.
10-14-2015, 12:10 PM
#6
so I have a 18 donzi classic with a 350 mpi and supercharged pushing 500hp. I am running 85 mph with my 27 but I was wondering I have 2 sets o 27 one set of 29 and 31 can I run 31/27 or 31/29 herd it is hard on the gears. can I get more out of my set up or should I leave well enough alone.Also im planning to put a padded bottom on this winter.
I had one on my 21 phantom ( UK ) hull whit 560 hp turning 29 props to 95 mph@6500 rpm but thats whit 20% slip .
I had the bullet of the prop shaft above the bottom of the hull which is what I found out was the way to mount it most info found on donzi .net where I thought seen you as well in some post .
10-15-2015, 04:15 PM
#7
I'm to low I have some of the cone in the water and from what I now is that you want that 1/2" above the bottom of the hall.did you try 31 on your set up sounds like you could use them that's very hi rpm.My boat is running great I just think this is going to take it to the high 90 for sure with my 31 or 29 and maybe a little more boost. is that a pad on yours too.
10-16-2015, 02:22 PM
#10
I was very high underside of the bullet in line whit the bottom of the hull ,but my hull hadn t had natural bow lift build in .
The rpm is high because I use ls engine that have over 550 ft /lbs tq from 3000-6300 rpm and made 550 hp at 6500
no no parts any more sold all to australia together whit both drives I had ,would love to tried some 31 s but could not find them at the time as they are the most wanted !!
The rpm is high because I use ls engine that have over 550 ft /lbs tq from 3000-6300 rpm and made 550 hp at 6500
no no parts any more sold all to australia together whit both drives I had ,would love to tried some 31 s but could not find them at the time as they are the most wanted !!
