porposing at high speeds [Archive]

dmontzsta

08-22-2005, 09:25 PM

What kind of boat is it? and what kind of set up? I think that will help answer the questions. :cool:

GofastRacer

08-23-2005, 06:23 AM

Yes we need info, what kind of boat, power, prop, gears,etc!.. :confused:

Sanger80

08-23-2005, 08:46 AM

and picts :D

mptheriot

08-23-2005, 05:38 PM

73 schiada, 454 at about 550 hp, casale 41 gears, 11x 15 prop at 12 degrees Runs good approx 90 at 5500 accelerating strong then bounces must slow down! All suggestions appreciated
Mike T.

ColeTR2

08-23-2005, 05:41 PM

41 gears
Put some 18's in it that is way to much gear!!!
73 schiada 11x 15 prop
How many feet long? Two blade or three? is it a flatbottom?

Moneypitt

08-23-2005, 05:48 PM

Yeah, maybe 25s would allow it to carry its weight throughout the speed spectrum......MP

MandDPerformance

08-23-2005, 06:11 PM

we've got 18's in our little flatty with around 1000 ponies. It carries the nose nicely through the 1/4 at 8600. :smile:
Formerly owned a 20' Schiada with roughly 750 hp. The setup: 11 1/2*15 Menkens with 22 gears at 92 MPH. 6700 rpm. Never porposed.
You have way to much gear.
What's up TR2?

V-DRIVE VIDEO

08-23-2005, 06:42 PM

73 schiada, 454 at about 550 hp, casale 41 gears, 11x 15 prop at 12 degrees Runs good approx 90 at 5500 accelerating strong then bounces must slow down! All suggestions appreciated
Mike T.
Mike,
Theres no way you could pull a 40 plus gear 5500rpm with 550 hosepower. Are you saying you have a 12 degree strut?
Try and figure out what you really have and post again. :confused:

ColeTR2

08-23-2005, 06:43 PM

What's up TR2?
Just hoping someone will give me a 11x16 CNC prop for my B-day.

johnmiller

08-23-2005, 07:50 PM

If you have a 12 degree shaft angle, forget about trying to make it go fast, it will always porpose. Big job, but changing the shaft angle to at least 9 degrees will make a world of difference. 12 degrees is WAY TOO MUCH shaft angle!!!!

dmontzsta

08-23-2005, 07:53 PM

wait...did I hear this right? 41 gears at 5500rpm? that would be ALOT more than 550hp and certainly more than 90mph.

MandDPerformance

08-23-2005, 08:09 PM

Just hoping someone will give me a 11x16 CNC prop for my B-day.
Keep hoping!!!!LOL. :cool:
MABE YOU CAN BORROW ONE THOUGH.

GofastRacer

08-23-2005, 08:19 PM

73 schiada, 454 at about 550 hp, casale 41 gears, 11x 15 prop at 12 degrees Runs good approx 90 at 5500 accelerating strong then bounces must slow down! All suggestions appreciated
Mike T.
Wow, if and I say "IF" you have an honest 550hp and with that prop, you need 15's 18's max!.. Are you saying 12 degree shaft angle?? :eek: You need an 8 degree angle if you plan on going fast!..

dmontzsta

08-23-2005, 08:22 PM

Is it just me? or do all old flattys hop around? that is why I switched to a B boat, plus the take a set and look bitchen.

MandDPerformance

08-23-2005, 08:24 PM

Is it just me? or do all old flattys hop around? that is why I switched to a B boat, plus the take a set and look bitchen.
Do we know for sure it's a flatty??

dmontzsta

08-23-2005, 08:26 PM

Do we know for sure it's a flatty??
Well...just guessing since it is an 18'.

GofastRacer

08-23-2005, 08:54 PM

Is it just me? or do all old flattys hop around? that is why I switched to a B boat, plus the take a set and look bitchen.
A flat is a flat, the main reason the old ones hop is because of the steep shaft angle, the steeper the angle the more it pushes the nose up, put an 7 1/2-8 degree shaft angle in and it pushes the boat forward, with the right gear, prop and power you won't get any hop!..

mptheriot

08-23-2005, 10:51 PM

DAVEY B

08-24-2005, 06:32 AM

had 18's in it originally. Engine tachs out too fast. These gears I can run a good speed without my engine sounding like its wide open. With 18's in it you couldnt run it as fast. Now it will go over 100 but not very stable
550 hp and 41 gears does not equal 100mph. :idea: In my SS 619 hp 18 gears good prop 7400 rpm ran 114 at Long beach very stable. K boats are the only ones run that big of gear. Also have your prop checked the ears could be laying back. :confused: Good luck

boatguy222

08-24-2005, 07:16 AM

Mike,
Were do you have your plate set at? sounds like it might be to high, Did you put "wings" on the strut like you were talking about? You can give me a call if you want, I have got a couple of ideas you might try.
Marc

Moneypitt

08-24-2005, 07:30 AM

How are you getting the speed number? Is this a seat of the pants guess, or some sort of speed insturment? Sounds quite a bit off......And if the boat is "bouncing", damm near impossible. 100 MPH in a flat had better be dialed in or you will not like the results. Even the fastest of the fast SSers can't run that speed unless the boat is on a rail. ........Regardless of actual speed, be careful out there, vest up, and even a helmet with proper restraining straps....MP

Carnivalride

08-24-2005, 08:51 AM

550 hp and 41 gears does not equal 100mph. :idea: In my SS 619 hp 18 gears good prop 7400 rpm ran 114 at Long beach very stable. K boats are the only ones run that big of gear. Also have your prop checked the ears could be laying back. :confused: Good luck
Davey B,
How heavy is your boat? What dia & pitch do you run? With a 16 pitch prop thats only about 14% slip which seems pretty good for a flat.

superdave013

08-24-2005, 09:18 AM

I'm pretty sure they don't make a 41 gear. The one's I've seen were either 40% or 42%

DAVEY B

08-24-2005, 11:56 AM

Davey B,
How heavy is your boat? What dia & pitch do you run? With a 16 pitch prop thats only about 14% slip which seems pretty good for a flat.
The boat weighs 1800 lb race ready the props i run are 11 to 11 1/4 dia pitch and rake is what ever dallas makes them i have 3 props that will all run within 1 mph of each other and all handle about the same. The speed reading is from my play back gps and a play back tach. so take it for what thats worth. The boat has always hauled ass in Long Beach

Carnivalride

08-25-2005, 09:01 AM

The boat weighs 1800 lb race ready the props i run are 11 to 11 1/4 dia pitch and rake is what ever dallas makes them i have 3 props that will all run within 1 mph of each other and all handle about the same. The speed reading is from my play back gps and a play back tach. so take it for what thats worth. The boat has always hauled ass in Long Beach
Is the 1800lbs with or without driver? Either way those are impressive numbers (114mph with 619hp). :supp: :supp: Good luck at the races. ;)
Loren