|
Originally Posted by sommerfliesby
(Post 3338906)
Thinking about bringing the boat home this weekend or next...I want to really clean up the bilge and I have to pump out the old gas.
|
Originally Posted by 10x
(Post 3338932)
Mike, first see what the #'s are on the dyno. You don't want to spin the engines any higher than you need to. See where the peak torque is and then the peak hp, then you'll have a better idea on what prop you're gonna need. Right now, you're only taking a guess.
Say your motor peaks torque at 4600 and peaks in horsepower at 5600. Where do you try to prop your rpms to? Thanks, Allen |
Originally Posted by 29scarab10
(Post 3339575)
10x,
Say your motor peaks torque at 4600 and peaks in horsepower at 560. Where do you try to prop your rpms to? Thanks, Allen |
Originally Posted by MILD THUNDER
(Post 3339671)
I've always tried to prop close to peak HP. But you need to be sure your valvetrain is up to the task. Propping too close to peak torque is hard on the drives, and can make for ill handling. I have a friend who ran 700hp 540's thru TRS drives for many years with no failures. He spun the motors around 5900. I think that was the key to keeping them drives together. Some guys cringe at the idea of anything over 5k rpm. A properly setup hydraulic roller can turn 5600-5700 all day. Solid rollers even higher.
Mike can't wait to see the new set up and go for a ride:evilb::drink: |
Originally Posted by MILD THUNDER
(Post 3339671)
I've always tried to prop close to peak HP. But you need to be sure your valvetrain is up to the task. Propping too close to peak torque is hard on the drives, and can make for ill handling. I have a friend who ran 700hp 540's thru TRS drives for many years with no failures. He spun the motors around 5900. I think that was the key to keeping them drives together. Some guys cringe at the idea of anything over 5k rpm. A properly setup hydraulic roller can turn 5600-5700 all day. Solid rollers even higher.
|
Originally Posted by 10x
(Post 3340013)
Allen, Joe is right here. Generally speaking, your peak hp will be 1000-1200 rpm over your peak torque. If your peak hp is around 56-5700 rpm, you would'nt want to spin the prop much higher rpm than that. Guessing that you have bravo drives, rpm does'nt hurt the drives, it's putting a big load on them that kills em. They'll last alot longer spinning the props at 57-5800 rpm, than at 4900-5000 rpm at wot. You'll just lose some mid range cruise speed. The bigger the prop, the better the cruise, but you'll sacrifice speed on the top. I'm guessing that you would need something in the 26-27 pitch area.
I typed that wrong. Motor peaks torque at 4600 and makes peak horsepower at 5600. Thanks, Allen |
Originally Posted by 29scarab10
(Post 3340182)
10X,
I typed that wrong. Motor peaks torque at 4600 and makes peak horsepower at 5600. Thanks, Allen Allen, I believe that's what you said the first time, you were correct, and that sounds about right. 56-5700 you'd want wot. :drink: |
A set of bravo 4 28 or maximum 5 will due well. The max isn't as hard as you'd expect. You may want to try the bravos with the std lowers.
|
Mike, there's a pr. of 5 blade 28's Hydromotive P5X's in the swap section. Might be just what you'll be lookin for. Check em out.
|
Had a similar set up on our last 35... 1 step, standoff boxes, 585 hp per side, 1.5 gears, max hp at 5600 rpm... no shorties, though..
29 Quad IVs 65MPH @4500rpm, 76@5000, Hit rev.lim.(5600) 85mph 29 P-5's 72 @4500, WOT@ 5200 87.4mph 31 5bl(CNC) 76@4500, WOT@ 5200 90mph Throttle up Hope this helps, we ended up with the Throttle Up 5 blades, but a labbed pair of Hydro P-5's was very close in overall performance. Carder |
| All times are GMT -5. The time now is 12:59 AM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.