Fenderjack

iTrader: (2)

I have seen them run/used on plenty of big boats. My question is would they benifit a small boat 21ft or so, make it run better. Any info on this matter would be great.. Thanks JOHN

articfriends

iTrader: (1)

Good question,not sure of the answer but I'll throw my experience in. I added a stellings 12" ext box to my 272 baja,it created porpoising,cavitation and a myriad of other issues plus boat goes 3-5 mph slower all the way around. Between the box and parts it added at least 100 lbs to my boat plus seriously moved my center of gravity back. I was hoping shifting the c/g back would help my boat but it only hurt it. You don't see boxes on shorter boats,probably because they are so small it screws them up royally.Maybe a land and see stern jack would be better for you and if you didn't like it you could easily pull it off instead of having to pull your motor backout and whole gimbal like I'm about to do.Julie at throttle up told me my boat didn't respond well to the box because I have a pad bottom and they work better on true vee's with a 24 degree deadrise plus the fact I only have a 25 foot actual hull runnning surface,Smitty

Fenderjack

iTrader: (2)

Hey man thank for the response, I would love to here from other. I also have a pad bottom, as the box would go on a 202 stinger. As you said I was thinking that it would make the boat think it is longer then it is and let more of it get out of the water..Only problem of a a stern jack is they don't make them asnymore for alphas

Thanks again

MACTIME

I would not recommend wasting your time or money. I owned a 222 Stinger that we installed a 502 w/blower, removed the alpha, and raised the X dimension when replacing with a bravo.

Was very disappointing! The boat chine walked dangerously at high speeds, the hull was never designed for in the 1st place.

KMP

Articfriends....

The Stellings extension box moves the drive and prop back from the hull 12" and is only adjustable 1" up or down from original x-dim. Did you keep the same x-dim?

If you move the prop back 12" and you run with your bow positive from level, you should be able to run a higher x-dim. If you did not raise the X, then you are actually running your prop deeper creating more drag.

Try adjusting your drive up. Then try a shorty if you can borrow one. Getting the drive up should be good for a few MPH.

articfriends

iTrader: (1)

When I installed the box I went up 1" above stock with std length drive. My prop was originally 7 1/2 below hull,with box it was 6 1/2 below the hull. Boat cavitated,porpoised wildly,breaks prop loose when on plane,handled rough water terribly,wouldn't carry bow well which is neccesary on my boat to run fast,felt real skittish and loose at high speed,plus went 1-2 mph slower than originally. I added a 1 inch spacer which put prop c/l back to stock depth,that cured 80 % of the problems the box created but boat still feels real squirelly at high speed when running light or in rough water,plus boat went even slower (3-5 mph slower than before installingn the box). I tried a 5 blade prop,slowed boat down another mph,even with spacer back out,plus put enough stress on my drive to shear off a prop shaft. I now believe that in my case the box fights the way the boat rides on the pad. Even if I were to buy a 5 blade and get it labbed and worked on,plus buy a shortie to try to get it up higher,I would have to gain 6 mph just to get back to where I started and theres no guarentee I could even get back to that point after spending another 5 thousand on more props and a shortie. Throttleup told me pad bottom boats don't typically like boxes and I am now convinced. Btw-the 3 sets of holes in the box (according to stellings)1st set puts prop at stock C/L ,neutral, (box is angled up),2nd set puts prop plus 1",3rd set puts prop plus 2",Smitty

JasonSmith

I think you need a bigger boat to do what you want to do, unless what you want to do is get hurt. Then I'd say you are on the right track.
Not busting your balls or anything, just my opinion. Hell you might be a brave S.O.B.....?

Fenderjack

iTrader: (2)

No not looking to get hurt but want this thing to run. I like being in something that i have to drive and stay on my toes, I know there isn't any ball busting here, thats your opinion, just need this thing to haul..

KMP

What boat/motor combination do you have? There are several people here with experience (and lots of $$$ spent) to do the same thing you are looking for. It's best and cheaper to do what has been tried and proven for your combination.

Tinkerer

What do you want for the stand off box??