??? about stand off box
 

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 :drink:

Re: ??? about stand off box
 

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

Re: ??? about stand off box
 

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

Re: ??? about stand off box
 

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.

Re: ??? about stand off box
 

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.

Re: ??? about stand off box
 

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

Re: ??? about stand off box
 

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. :eek:
Not busting your balls or anything, just my opinion. Hell you might be a brave S.O.B.....?

Re: ??? about stand off box
 

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.. :evilb:

Re: ??? about stand off box
 

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.

Re: ??? about stand off box
 

What do you want for the stand off box??

Re: ??? about stand off box
 

I have a 202 chris craft stinger. I am curently putting togather a 355ci chevy(400hp). I am just checking to see if this would be worth it since I see them alot, only on big boats..

Re: ??? about stand off box
 

Best return will be to put a 383 stroker kit in it.

Re: ??? about stand off box
 

Just curious why would the 383 be better then the 355?? Just because of more tq, the boat only weights about 1800 lbs..

Re: ??? about stand off box
 

It´s interesting to see how the extension box issue keeps coming up again and again.
Well my 25 Outlaw has now got 60 hours on it since I fitted the Imco box (with 3" raised x) and it show absolutely no handling or performance problems - and runs 81 mph on the same power (525) as Baja only quotes its boat to do 75 mph with!
Yes is does feel like a bigger more capable boat, reacting beautifullly to trim and steering inputs.
I´m totally happy with the convertion and a friend just put the same settup onto his 29 Aerotek (runining 900 hp) and is equally convinced.
Like KPM said - due to the angle of attack that a planing hull runs at, 12" back has to be accompanied by raising the x sufficiently.

Re: ??? about stand off box
 

How big is your pad on your boat? As I mentioned before in previous threads we have talked on before the 1 inch above stock combined with the 12" setback absolutely screwed up my boat and the 1 inch spacer got rid of 80% of the box created problems but slowed boat down even more. I think there is a direct relationship as to how the box reacts compared to true v-hulls and boats with pads on them,Smitty

Re: ??? about stand off box
 

I am in the process of building up a 24' P&D (Same hull as the Pantera 24)

It has a small pad similar to your Baja. However I am using an IMCO with a 3" rise. This will put the X at 20.5" (17.5+3). I am setting it up exactly a couple of Corsa's that competed against each other for a few years. Yes it will have long tabs.

Re: ??? about stand off box
 

Ok, my boat is a '93 Checkmate 230 Enforcer and it doesn't have a pad whatsoever..
21 feet of hull ..24° deadrise and a 7' beam....Propshaft 6.5" below the keel.

Do you think I could possibly benefit from an extension box??


Next question is.. would I have to raise the engine at all??


Thanks,

Doug

Re: ??? about stand off box
 

THE PAD ON THE 25 OL IS WIDER THAN MY 24 Ihave a 2'' shortie no box and picked up a lot of speed over stock

Re: ??? about stand off box
 

I have been told by several reputable sources AFTER installing my box with negative results that boxes work better on true v-hulls. I'm no expert however. I was able to use my stellings box in the plus 1" position with just very small changes in my engine position and was able to achieve about a 3 degree angle on the driveshaft. That put my prop1 inch higher than stock. It caused my boat to porpoise,blowout,cavitate and drive like crap in rough water. I was able to get rid of 80% of the ill effects by adding a 1"drive spacer but I lost speed from the box and lost more speed from the spacer. The box could be moved up another inch to achieve 2 inches above stock but motor would either have to be raised 1/2 inch to get 5 degrees of driveshaft angle or you would have a 7 1/2 degree angle which would be alot.I would be leary about moving drive back 1 foot on a 21 ft boat and up after my fiasco this summer but you could either find someone who did it on a similar hull as yours or just do it and see what happens,Smitty

Re: ??? about stand off box
 

heres some pics as installed it

Re: ??? about stand off box
 

you have a small pad like me and the 25ol has a wider one ,and he likes his I would to at 81mph at 5300 with a 28b1 with a 525

Re: ??? about stand off box
 

Do you know where I can find a reasonably priced used one? :rolleyes: :D :D



Doug

Re: ??? about stand off box
 

Boatally, I bought a used one for my checkmate but I never got the chance to try it yet. I would consider selling. It is an Imco with ears and drive shaft. I also have a bravo with Imco 2" shortie I want to try but may be willing to sell. Let me know if your interested.

Re: ???
 

I HAVE A 2000 288 SUNSATION WITH A 12 BOX I TRYED MOVING THE BOX UP AND DOWN ALSO USEING ALOT OF DIFFERENT PROPS THE BOAT LOST SPEED BUT HANDLES GREAT IN ROUGH WATER MY FRIEND HAS A 2002 HE PUT ON A IMCO 2" SHORTIE BOAT WENT FASTER AND HANDLED BAD WITH A 1" SPACER AND A LAB 5 BLADE HE GAINED 2MPH AND GOT HIS HANDLING BACK .HE GOT THE SHORTIE DRIVE FROM SUNSATION TO TRY OUT SO HIS TESTING WAS FREE HIS BOAT IS FASTER THEN MINE BUT MINE HANDLES BETTER WITH THE BOX AT THE SAME SPEEDS . YOU DONT HAVE TO MOVE YOUR MOTOR UP IF YOU USE THE SETTING ON THE BOX I MOVED MY MOTOR UP 3" AND GLASSED UP THE HOLE AND THEN CUT A NEW HOLE UP 3'' PUT THE BOX ON THE HIGHTEST SETTING WITCH MADE MY X 2" UP FROM STOCK

Re: ??? about stand off box
 

why not try your buddies 2'' shortie at the end of the season with the 5 blade