GOT NEW MOTOR NEED NEW PROP

[HavasuBarney]

My prop has been worked. I had the diameter cut, blades thinned and cupped, 2 inch holes drilled.
Mine is actually closer to a 27 then a 26 now. At 7000 rpms, I'm running between 95 and 99 depending on load.
Did you say you have a Bluewater trim gauge?
Do you know the angle of attack your running?
Gear set?
You may have too much positve trim running and your not getting enough bite and just spinning your prop. It's turning the rpms that way but your not getting effective use.
Typically DCB's do not run enough setback, those Dana Brackets are bitchen but may not provide enough lever for you to run efficient.
With the design of an air entrapment hull, you should be running your top speed with 0 trim, none. Prop shaft should be level with the surface of the water.

[ March 19, 2003, 08:43 PM: Message edited by: HavasuBarney ]

[HavasuBarney]

This was one of my testing days last year.
26 Hydromotive
26 Trophy
26 Hoss
28 ChopperII
30 Cleaver
30 Yamaha Drag copy

[TOBTEK]

HavasuBarney:
My prop has been worked. I had the diameter cut, blades thinned and cupped, 2 inch holes drilled.
Mine is actually closer to a 27 then a 26 now. At 7000 rpms, I'm running between 95 and 99 depending on load.
Did you say you have a Bluewater trim gauge?
Do you know the angle of attack your running?
Gear set?
You may have too much positve trim running and your not getting enough bite and just spinning your prop. It's turning the rpms that way but your not getting effective use.
Typically DCB's do not run enough setback, those Dana Brackets are bitchen but may not provide enough lever for you to run efficient.
With the design of an air entrapment hull, you should be running your top speed with 0 trim, none. Prop shaft should be level with the surface of the water.
HMMMMMMMMMMM..interesting. Yes I do have a bluewater and its usully around 2.5 or 3 at speed. I'll try lowering it back down and check it out. Your Bravo looks WAY different than mine. Id love to try it out sometime. They just drilled 1" holes in it...."your holes are bigger than mine" hehehehe I cant remember the gear ratio's but I know I have the lower gearing 1:75??? I think instead of 1:62??? if memerory is close?? anyway thanks for all your input Barney....tobtek

[HavasuBarney]

That makes a big difference, I'm running the 1.62 gear ratio. Maybe a 28 is the ticket for you.
I might even sell you my 28 if you like it. You are more than welcome to try both when your here.
If you were able to maintain the same slip factor moving froma 26 to a 28 pitch, at 7000 rpms you would be running 94+
If your prop shaft is not level with the surface of the water, it increases the amount of drag on the gear case. With positive trim it will be slightly dragging the nose and with negative trim, it will be plowing.

[ March 20, 2003, 11:35 AM: Message edited by: HavasuBarney ]

[ZSARGO]

HavasuBarney:
That makes a big difference, I'm running the 1.62 gear ratio. Maybe a 28 is the ticket for you.
I might even sell you my 28 if you like it. You are more than welcome to try both when your here.
If you were able to maintain the same slip factor moving froma 26 to a 28 pitch, at 7000 rpms you would be running 94+
If your prop shaft is not level with the surface of the water, it increases the amount of drag on the gear case. With positive trim it will be slightly dragging the nose and with negative trim, it will be plowing.
IF TOBY HAS THE SPORTMASTER, WHICH I'M SURE HE DOES, THEN HE IS ALSO RUNNING THE 1:62 GEAR RATIO. I WOULD LIKE TO TRY OUT YOUR PROPS NEXT WEEK IF YOU DON'T MIND. I WAS IN HAVASU ON TUESDAY AND TRIED TO CALL YOUR WORK AND CELL. YOU MUST OF BEEN OUT PLAYING. I TOOK THE COWLING TO CUSTOM AUTO TRIM. ANYWAYS I WILL CALL YOU NEXT WEEK AND TRY TO GET BY THE SHOP.

[Boatmaster]

Toby's 300Xs has 1.75 gears thats the way Dave rigs them to help with hole shot and mid range.

[ZSARGO]

DREW,
I'M SURE TOBY WISHES HE HAD 300(X'S). DOES THAT MEAN WITH MY 1.62 RATIO I WILL HAVE MORE TOP END?? ALL THINGS BEING EQUAL?
[ March 20, 2003, 04:21 PM: Message edited by: ZSARGO ]

[HavasuBarney]

ZSARGO:
DREW,
I'M SURE TOBY WISHES HE HAD 300(X'S). DOES THAT MEAN WITH MY 1.62 RATIO I WILL HAVE MORE TOP END?? ALL THINGS BEING EQUAL? In theory, things would stay equal because he could turn a higher pitched prop.
I blew up a couple lower units on my 98 300, it still had the small prop shaft. Parts were on back order and so I bought a new sportmaster so I would not be without my boat for a couple months. Before I bought it, Lou let me test a 1.75 gear set sportmaster.
With my set-up, I could only turn the same props as with my 1.62. I found no advantage to the 1.75 gears with hole shot but I was slower.
When I say turn a prop, I mean running with no trim and putting the tach on the limiter.
Still, every boat is different and there's no question Dave has put together many more of these boats than I have, I would trust his judgement. Unless you got 1.62's wink

[Boatmaster]

Zargo I would think you will be alittle faster on top end, do to the fact that a lower pitch prop normaly has a lower slip factor. My own feeling is the taller 1.62 gears are the better set up.

[ZSARGO]

Boatmaster:
Zargo I would think you will be alittle faster on top end, do to the fact that a lower pitch prop normaly has a lower slip factor. My own feeling is the taller 1.62 gears are the better set up. OH OH. YOU KNOW WHAT'S GOING TO HAPPEN WHEN TOBY READS THIS. HEADS UP DAVE.