why no tabs? we run 380s on a 25 footer they make a world of difference in ever changing conditions

Can you Eloborate?
I have had V-bottom boats my entire life.
so help on the Cat front is new territory

I would think they would help getting on plane.

I would think they would help control the porpoise.


thank you
Cougarman

Been a while. Any testing with different Props? Neat Cat but setting the drive height and getting the right Clever Prop is The Art of the setup. The Magic that everyone talks about but few totally understand with all the variables. I have a New 28 foot Cat hull that is ready for cutting "the hole" so your post is something to learn from for me.

From all that I know, which is not much, but I ask a lot of questions. On a Cat the X dimension is sort of out the door with all the different center to center dimensions for different drives. then add the different extension boxes and all changes if they are used.

To start with adding a box, as you have with a #6, increases the prop centerline height above the kell or lowest point of the hull. So, Yes you are already to low at 1 inch above the kell with a box. It should be up at least 2 more inches, 3 would be better and then add a spacer to bring the drive down if necessary. A lot can be done with Props. What Prop are you running to start with, Dia, Pitch, Rake? Everyone thinks more rake is better but to much will lift the stern right out of the water as you are describing.

This is/was Current set up at the start of this thread, obviously to low and causing the bullet on the #6 to act as a trim tab.
We believe it pushing the bow down & picking up the transom

Starting over, lets see what we learn



Drive has been raised 2”



We are also going to fill the notch on the center pod which provides another 1”



So, we should be 3” above that bottom with these changes.
this will allow additional testing including being able to space the drive down if needed



Also a few different props to try & see what we learn too
3,4,& 5 blades options along with some different Diameter options too… Being a single Screw

Have any photos of your set up to share?



Thank you
Cougarman

Not an expert, but I'd consult with https://www.wilsoncustommarine.com/blueprinted-drives

The NXT is known to have a big fat bullet that provides too much transom lift for many boats. The VI drive doesn't do that. But there are tradeoffs. I would think Wilson Custom Marine would be my first call.