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1.5:1 28p vs 1.36:1 26p

Old 10-12-2020, 12:53 PM
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Default 1.5:1 28p vs 1.36:1 26p

Looks like I ate a drive yesterday testing a new RH 28P after running LH 28P since new. Lasted 2 miles going the other direction.
I have been trying to tune out of torque lean and thinking of spinning a smaller prop faster.

I am turning a stock B1 28P LH to 5400RPM. Since I am rebuilding a drive, I am thinking about trying 1.36 gears and working a 26P prop. On paper at the same RPM and slip, the 1.36 is faster.

Any experience?

Last edited by TxHawk; 10-12-2020 at 02:06 PM.
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Old 10-14-2020, 01:28 AM
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I'm surprised that happened from swapping rotation. Its actually slightly harder on Bravo drives to spin LH. It may just be a coincidence.
Generally a 1.36 spins about 600rpms less than the same prop with a 1.50, so really you would need a 25" prop to spin the same rpm or lab the 26 for an extra 200 rpms.
I have 1.36's and kinda wish I had 1.50's for the simple fact of being able to find one quickly if I need one. Its really not worth it $$ for me to switch though and my boat is dialed with them.
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Old 10-14-2020, 08:01 AM
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Originally Posted by Griff View Post
I'm surprised that happened from swapping rotation. Its actually slightly harder on Bravo drives to spin LH. It may just be a coincidence.
Generally a 1.36 spins about 600rpms less than the same prop with a 1.50, so really you would need a 25" prop to spin the same rpm or lab the 26 for an extra 200 rpms.
I have 1.36's and kinda wish I had 1.50's for the simple fact of being able to find one quickly if I need one. Its really not worth it $$ for me to switch though and my boat is dialed with them.
I have considered that it may be coincidence, just weird it happened so fast.
I am looking for speed obviously but also considering how a lower pitched prop spinning faster may help with the torque lean in a 7' wide boat.
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Old 10-14-2020, 08:11 AM
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I did the swap on my 28' cat. Went from 1.5 and a 32" prop, which was slightly over propped to 1.36 with a 28" prop. ran the exact same speed, 105mph. Whether or not it would help the torque lean, I have no idea, but I am of the understanding that running a LH prop helps. Both of my Advantage V hulls were setup LH from the factory.
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Old 10-14-2020, 11:04 AM
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If it helps , I went from a 1.65 to a 1.5 It was a 4 inches of prop difference.
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Old Yesterday, 12:53 PM
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Thanks for your input all.
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