"notched transoms"...???

[oldLenny]

Does anyone know "why" these work, if it allows a higher "X" dim really, and are there performance gains...
I can only see it bringing cleaner water to the drive and thus propulsion (less slip) and maybe a raised drive therefor less drag. Does it work?

And how does a boat benefit from all of a sudden becoming "shorter in length" than what was originally there and does the ride suffer having a perfectly flat 6-8" portion at the transom on re-entry???

Lots of questions. Need GOOD answers please wink

[MOP]

The only notched boat I rigged and tested and worked on some afterwards was a Switzer, we ended up with the only the gear case below the bottom. It was a 21 footer with a 200 Johnson, I got to run it against a Tahiti, I think an 18 with a 235 Johnson. The switzer was quite a bit faster, what was spooky was when you chopped the throttle it just skimmed along like a "No Brakes" feeling till it dropped off plane. In my mind the notched transom is a faster combination.

[PaulO]

Leonardo,
You are absolutely right. The notch basically amounts to a setback for the outdrive allowing higher X dimensions and cleaner water. The trade-off is that you lose real world length. A better modification would be an extension box with a raised X.
PaulO

[MOP]

How much would the lose of length do to speed with most of the boat out of the water at speed?

[Bryan Tuvell 33ZX]

Lets just say the next 38ZX coming to the HRPA in a few weeks has a notch in the transom, we have the photo's, so it must work, I believe it is similar to the ZR bottom. The Red Gelcoat bottom is sweet also!

Just in from the latest HRPA gathering, we enjoyed the pictures of Greg's new 38ZX Donzi provided him.

Just FYI for those that watch bottoms. :D

Bryan

[Ed Donnelly]

I had a pad and a step(notch) on my 16 in 1974.snall block twin turbos. Made it much faster but the pad was a big mistake. Pounded like crazy in any kind of chop.I also extended the cavitation plates to make up for the lost length.Cavitation was also a problem in high speed turns. Hope this helps..Ed

[Walt. H.]

Yep!
My Carlson cvx-18 has a padded hull and what I gain in speed on calm water I lose when in the choppy stuff, And on the Hudson i'm always in the choppy stuff :mad: throttling back. :( $#@%
up dated explaination 6/21 @12:noon
At speed it rides on the narrow center pad like a water ski, less boat in the water is less drag to slow it! :p Negative side is = it slap's in the chop. :mad:

[MOP]

I have a bunch of small boat dealers out by me, I have noticed a lot of the new boats come with the notch and don't have the pad. A buddy sells Pro Sports they are notched and set up with the engines pretty high for a fishing boat and run real well in nasty water with a good sized notch. I ran a lot of them last year, no problems with cavitation. The pad is what screws up the ride, how much does it do for speed once up and going. In thinking about this, the notch to me would be better than moving the running gear back. It would also be far more cost effective for a production builder. The extension boxes and bracket for outboards are the only way to go with an already built boat and do make a lot of difference. I remember when Grady White sent us the first bracket boats, the basicly same exact boat, last years with the standard transom was a fair bit slower at top speed with the same HP motor.

[Jake]

I am a little lost. For those of us who are unfamiliar, is a notch the same as a stepped hull? If anyone has any pictures, I would love to see the difference if there is any. Thanks.

Jake

[Shanghied Again]

We just had 3 38ZXs 1 Daytona notched and 1 Standard notched. I also sold a 38ZX with the normal bottom all 525s one with the XR speedmaster bottom. The Daytona GPS 28 Pitch Lab 79.5, 30 pitch Lab 78. The 38 ZX knotched 525s Speedmaster bottoms 28 Pitch lab 74.5 mph. The 38ZX Bravo XZ drive 525 30 pitched, 80.5 mph gps/ I see no change maybe a little loss. I am asking DONZI to send me a pair of 30s non labbed to try on the Daytona, Hopefully I will see a big difference.

[Bryan Tuvell 33ZX]

Good data Frank, I will pass to Greg, his will have HydroMotive 30's (5 blades I think), 525's, Sportmaster Drives with ext boxes etc, he also got the Gen-set, and all the goodies.
He expects to be 80, his goal, I think he will make it...
I will email you the pictures.
He is working with Donzi to post a thread on the boats construction etc... she sure is pretty.

Bryan

I sent this link to Greg, he certainly knows more about his set up than I.

[Shanghied Again]

I will be taking pics of the Daytona we just sold, WOW a custom paint job from Donzi (She is Awesome!) My hats off to Donzi for a paint job well done. I drove the 38 to NY City and back (My Job Is Real Hard to do) I fell in love with the 38, Maybe not the fastest but the most comfortble Offshore boat out there. PS We are now a Cigarette Dealer

[Bryan Tuvell 33ZX]

I have enjoyed this thread, great data on hulls for us uneducated about classic's guys.

Frank, I hear ya, like I tell Greg, top speed in the ocean/bay is not the issue, the 38ZX at 70 will out do all it's competition when the **** hits the fan in the big water...

If you run across another Cig 30' twin 500 boat call me at home. The 01 Cig T500 we called on sold, and the 01 Cig twin 496 boat we were sniffing (waited him out too long) from Harry also sold two Saturdays ago, day late and a dollar short at times.

We are no longer looking at 28's & twins, not cost justifiable over what we have.
Bryan

Hoping to see some bottoms today! :D
Taking DIGGER to Kerr Damn :)

[MOP]

Had a crappy rainy day so I decided to go and look at a few bottoms at one of my buddies marinas. That lead to four more places, I found mostly fully notched but did see some with about half the transom notched leaving more planing area outboard. I wonder which works better or maybe a high speed it is irrelevant.

[Bryan Tuvell 33ZX]

Frank, were these runs in the 38's just break in runs or were these boats ready to rock and proved these numbers as reliable data?

We are all excited to see Greg's new boat! And to get in line for a ride.

I hope you and Melissa are well, see ya soon up north, and keep your eyes pealed for me on the 30' Cigs with steps and 500's.
Bryan