eliminator25

The porpoise is common in cats my 25 does it about 75 mph. My buddies 33 daytona does it about 110-120. The way to get through it is steer left too right a little bit or give it more gas too pull through it. My buddies 28 doesnt do it because the boat only goes 90 mph not fast enough to start lifting the boat.The 33 was smooth as silk at 140+ and mine is smooth at over 100mph.

B BOATER

33 no porpoise here. They changed the hull.

CheckedOut

My 25 doesn't porpoise at all.... it's an 08. They must have changed the setup.

eliminator25

How fast does it go? My buddies is a 2006 33 daytona with 2 1100 hp engines I built. Only 2 years old I would be surprised if they changed the hull. If you accelerate hard you wont even feel the transition. Most boats dont go fast enough to get on top of the air like the cat was designed to do.

eliminator25

How fast is your 25. I was told by eliminator that the older boat have faster hull design. Mine only has a single deep step yours has a double shallow step. The porposing is only at a certain speed if you accelerate through that speed you wont even know its there.If you dont go fast enough you wont either. Example my buddies 2008 27' daytona doesnt do it because it only has a 525hp and only goes 80mph.

B BOATER

Just got this one last week best its ran is 137 on the limiter. Tony from Eliminator ran it at elsonor at that speed with 40 pitch props ran out of room. The lake is real short loke 2 miles so from start up to shut down not much room. Trying some different 40's soon hope to break 140 with it. Should be one of the fastest 33's with its power. They have changed the hull I can show you. They narrowed the rear of the tunnel to compact more air lifting the back of the boat. Dont know if they want anyone to know but I can show you.

B BOATER

I believe the hull change first started to take effect during the ICC packages as you might have noticed the speeds are rising on the boats. Props that we ran in the past do not work now there is alot more lift in this hull compared to our 30 which ran 116 at loto shotout with 620 teagues. Top speed was 119.

B BOATER

Sorry i keep thinking about all the different hulls we have ran an just thought about it our 06 27 daytona ran 126mph with a pfaff 1000 and it also had no porpoise at any speed. The only hulls that I can remember doing it were the 36 and the 33. The 30 was a hull change and has yet to be changed the 33 was redone not to long ago. Think the 36 still does but wouldnt doubt that the speedster and coupe have been redone since.

Adrenaline Junkie

My 36 has a porpoise from 85-95mph unless I have a tiny bit of tab in the water (ie. between 0 and 1), and trimmed in slightly (ie. between 1 and 2). (ie. so after I get up on plane and start running, I'll adjust the attitude of the boat to be slightly below the horizon line (learned this in Tres's class) and consistently work the trim and the tab to keep the proper attitude of the boat -...as I begin to pack more air and approach 100mph - I'll actually begin to trim in from 2.5 to ultimately under 2 and bring the tab from 0 to about .5 - .75 - and will have no porpoise and achieve top end speeds...if I come off the tab, I will actually slow down because the attitude of the boat changes slightly.

If I deviate from this (ie try and just run trimmed out to 2.5 -3, and no tab at all - my boat will porpoise until it works through that transition - fortunately, I've learned how to avoid it and achieve top speeds.

One other thing I learned is prop diameter can play a big role in these cats. Running with 15 x 34 labbed 5 blades the boat felt right. I through a blade in Havasu, and merc set me up with a 15 5/8 x34 labbed 5 blade - ended up having too much stern lift. Was real difficult for me to pack air running down wind - and obviously tough to achieve speeds - running upwind I could finally get up to speed, but it would take a while.

I just tested some 4 blade 32's and loved the way the spun up - very quicly got up to speed..they were 15's and didn't have the stern lift problems of the 15 5/8 34s - accelerated nicely, banged the rev limiter consistently, but hurt me on the mid range and top end with the 5 blades at 4k, I'd be running 80 and topped out at 122.9mph gps..with the 4 blades at 4k, I'd be running 68 mph and was only able to pull 112 mph with roughly the same conditions.

Going to test some 4 blade 34's next to see how they perform...

CheckedOut

My boat is somewhere in the low 70s. Still working on props and may repower it soon. Sounds like I may not be getting to that porpoise speed with the current setup........