Extension box on a single engine cat
 

All right guys and gals,
I've tried to do as much digging as I could and have not came up with a good answer yet. I was thinking about putting an extension box on my 26' Daytona 3" raise 12 set back. I know there are several out there so I was hoping to see if somebody has any feedback about doing this. "GOOD OR BAD" Thanks for the help.

I dont know if this helps or not but my daytona with out boxes had problems getting on plane sometimes depending on the wind and waves.. i rode in the same boat with boxes on it and it had no problems getting out on plane. you also might gain or loose some mph.. i would call eliminator and ask them bob leach would be the guy to ask.

It works great I had one on my last boat. You have to get the x dimension right tho.

Go for it. We installed several IMCO boxes along with their 2" shorter lower housing on some 26's and a 27' Daytona years ago. They all responded very well, picking up in fuel economy, cruise speed, and planing ability. Some customer chose to re-prop, others were satisfied with their original prop's performance.

Awesome guys thanks for the help. Did it help with control at tops speeds on do anything to the numbers up top? Seems like it mostly helped out on planning and slower speeds from what you guys are saying. Thanks again for the feed back.

bump

If you get the X dimension right , probably mean also adding a 2" shorty as mentioned above, you should pickup in all categories. But now you are also surfacing the propeller so a propeller change will most definitely be needed to get the added speeds capable. JMO

I built an IMCO -3 / Mercruiser X drive this winter. This will put my prop shaft 1/2 inch above the lowest point of the bottom of the hull. I am running a -2 IMCO right now with a 28 Bravo and 650+ HP at 90MPH.
You say that it helped getting on plane and fuel eff. Was that because the prop shaft was now lower in the water with the box than without? With the box did you go up higher than without?
You said that you had a hard time getting on plane - What was the prop shaft height and what prop?
What was the prop height with the box?

All good question tinkerer. I also would like to now there they were at before and after that davidwademarine was talking about.

This is my first cat and I have learned many years ago that set up is just as important as HP.
I am trying to do it right the first time. If a box is the right thing to do than I will have to buy one.
I know why you install a box on a V bottom. Higher X dimension, cleaner water, better bow lift.
But - why do you need bow lift on a cat. The air in the tunnel should lift the bow.
On a single engine cat at speed will the center pod even be in the water? If it isn't than the water should be clean even without the box.
I know that the further back the water comes up coming off the boat depending on the speed of the boat. SO further back you get the prop the higher it can be and still get the same bite. BUT how does this help. Couldn't you just mount the drive at the same height without the box and have the same results?