stability questions in a 25 daytona

[pleasantcat]

ok guy's in my quest for speed i encountered something i never felt in my cat. it feels like chine walk. i didnt think a cat would do this but as i run to 114mph it starts to dance from side to side and that's where i back out.i tried trimming her in but that doesnt help and a spectator said it looked as if it were ready to take flight. i have the 25 daytona 2step bottom with a high "x" (gimbal on the rub rail and 2" shorty imco lower) prop that gets me there is a 31 herring 5blade. i'm going out to try a 30 to see if there's less lift and it goes faster. with the bravo 32 prop i get 112mph solid on the water. i try a 34 and it wont hold the water during planeing. any ideas???

[Havasu Hangin']

I'm an idiot (so consider the source)...but maybe that 5 blade is lifting the stern too much? Maybe that's why trim doesn't help, and the 4 blade is planted?

[pleasantcat]

that's what i was thinking. but they say with testing they can eliminate it. sucks that the 34 blows out trying to get up :burningm:

[Havasu Hangin']

that's what i was thinking. but they say with testing they can eliminate it. sucks that the 34 blows out trying to get up :burningm:
You know...when I was at GT, I was talking to a guy who had the same problem. He solved it by installing a bigger cavitation plate on the drive (where the drive shower pickup bolts to). I think IMCO makes them.
He said that it kept the prop from sucking air coming out of the hole. It's just a piece of polished stainless plating (gotta be cheaper than a prop).
Just a thought.

[pleasantcat]

already on there :rolleyes: my x may be too high.

[Havasu Hangin']

already on there :rolleyes: my x may be too high.
Maybe it's time to try some spacers...

[Craig]

Hey dum bass, I thought those were Hydromotive props you and Charlie were dropping the big green on :D
As for the stability issue I talked to a few engineers here at work and they all agreed with me, problem is the loose nut behind the wheel :hammer2: Just kiddin', but do be careful, don't want to see you break your a** before the parade of lights day :wink:

[oknozelman]

My 24' dose the same thing but mine is a trim thing if nI trim down it stops, but it also slows down. I don't know if is the trim or the speed? But mine only runs bouy 105.

[oknozelman]

And I'm runing a 32pitch 4 blade Bravo :shift:

[WETTE VETTE]

I have heard of guys making the bolt-on cavitation plate a little larger on the IMCO shorties. This has been done to help in planing for certain props. Rod at Performance Marine in Oshkosh WI. has done this and claims it has no negative effects and helps the boat get on plane. This may be worth a try for your 34 Bravo. My WPM feels different with the 5-blades as well. Not scary, but definately different. So far I like Bravo props better, but I still have some more playing to do with the 5-blades before I give up on them.
Craig

[Craig]

Friend of ours made some cav plate extensions out of titanium. Really helped getting on plane with the bigger prop, especially with my boat which has never been a rocket out of the hole :p

[boatslayer]

i just say wing it out ,and take the walking :D
haha

[Charley]

I'm an idiot (so consider the source)
This just begs for an "AMEN" :wink:
Just kidding.... I'd agree 5 blade may not be the best prop for his setup stern lift can create exactly these symptoms... the good news is it doesn't burn when he pees :2purples:

[Havaparty]

Quick question, If you are looking at the prop installed on the boat, is the flange fluted like the end of a horn or does the flange look like the end of a pipe? I've heard that the fluted style will give you more lift? I think?

[Blowin Money]

The flare ring on the barrel of the prop puts water to the end tips of the blades for take off.

[pleasantcat]

ok so does anyone have a two step daytona that has been thru this? you cant compare the single to the double. life insurance is payed up but i would wrather not use it ya know :confused:

[Craig]

Come dude, leave the skirt in the truck and git with it :wink: j/k Got my motor back in the boat today :D

[Whipple Charged]

I think the 5 blade is lifting the ass of the boat which is causing it to hop. I don't think it's ready for flight, any 25' going 114 will look out of the water. I have a 28' with big power, dual motor with 36 5 blade heirings and at 145, mine starts hopping, if I full throttle it there, it will stop but I don't have the sack to see where it hops again. Problem is that no other 4 blade prop can get the boat up on plane. I have 36 pitch 6 blades, cavitation plate which must be at max down to get on plane, 1.25 gears, Imco drives high X dimension and extra weight in the back so it has to have the 5 blades.
Have you tried full fuel tanks vs. light fuel tanks? Might respond to more weight vs. the light load.
Thanks
Dustin

[pleasantcat]

dustin thanks for the reply. no, i have not tried full tanks yet but good idea. i know those hemi's your running weigh a ton and the last time i looked at your boat i think our "x"s are right about the same. like you no four blade with enough pitch to run will get me on plane. next week i'll try the 30p 5blade and post the results.

[Blownboat]

Silly boy, those are hydromotive props p5x. :messedup:

[pleasantcat]

dough!!! :notam:
herring,hydromotive,close enough :squiggle:
sorry guys i was wrong. the prop is a "HYDROMOTIVE" but, due to weather and nap time i didnt get to try it this weekend. after dustins post im going to try a full load of fuel as well.

[Robbie Racer]

Pleasantcat, there is a good thread going over on OSO about the 25' Daytona's running the 5 blade props. http://www.offshoreonly.com/forums/showthread.php?t=89678
What drive and nose cone configuration are you running? I haven't tried a 5 blade on my 25 Carrera cat yet but I can relate to the problem you mentioned about trying to get the boat on plane with the 34. I had the same problem with a lab 34 until I sent it to Houston Propeller to put their "Bravorator" treatment on it. I think they cupped it a little so now it gets on plane easily with my Imco SC lower on my B-max upper. But, when I switch over to my Bravo lower with the WPM nose cone, I still have a hard time getting the boat to plane with either my lab 32 or my modified 34. Both props will get the boat on plane easily with the Imco lower. Both lower units are the same X dimension so I can only assume it's the nose cone design that allows the Imco SC to work better at getting on plane.
Good luck,
R/R

[Craig]

Good info R/R, but I HATE I can't look at a freakin' picture on that site without paying some dues! :angry2:

[pleasantcat]

thanks r/r. i believe a friend of mine with a membership put that on there. he said lot's of info is on there and tells me about anything constructive. he's been there when i made the runs and for some reason wouldnt go for a ride :notam:
well i have to work saturday so looks like sunday is the big test day with the 30p and full fuel load.

[Blownboat]

Sean, that is the same thread I started for you.

[Blownboat]

Ya okay I admit it was me. After seeing that boat dance side to side about 3 feet I chickened out. What can I say. I have a small set!!!! Thanks for bringing it up sean!!!!!!!!!!!!!!!!!!!!! :( :lightsabe :devil:

[pleasantcat]

oh c'mon you big baby. looks like the weather goons are calling for rain this weekend as well :cry: :cry: :cry:
im never going to get this dialed in :frown:

[Blownboat]

:cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry:

[Craig]

:cry: :cry: I agree with you Blownboat, I just have to bolt the blower and intercooler back on mine, a few hoses to hook up and then fire it back up! Want to get that done so I can go out weekend before Thanksgiving.