3" RISE Extension box
 

Does any one have any have any experience with my boat or close to it with extension boxes??????????

1993 24' Outlaw 500HP

With my boat in pieces i am wondering if this would be a advantage for top end.
I hate to go threw all the work and have it be a waste of time and $$$$$$$$$
Any thoughts,
thanks

Wild card 09 picked up all kinds of speed from doing it on his 25 outlaw w525 efi,I picked up zero and actually lost speed and handling on my 272 w/blown 540 with a stellings box ,1 ft back and 1" up,Smitty

Do you know what year Wild Card 09's boat is????

Look thru the Baja section,he has posted there ALOT,Smitty

Just picked this thread up!
My 25 Outlaw is July 2002 delivered 2003 496HO boat with an X drive.
Stock, it did 67 mph @ 4900 on a labbed 25" Bravo maxed out.

I fitted the 3" lift box, together with a complete 525/XR package
and my best yet is 81.2 mph @5350 with a labbed 28" Bravo.
The handling improvement is incredible (response to trim and rough water ride) and I can´t find a fault with it in the 120 hours since I did the conversion in june 2006.
Mid season, hot days and with a full tank, I still see 78 mph.

Whether it works on the 24, I don´t want to garantee. The hulls are quite different, I think.
25 has a pad bottom and a notched transom.

WELL, it looks like you drive alot like me. cool pics
Thanks for the info
I'm going to try one it seems like its worth it. My boat should respond alot like yours.

Great! This will be interesting. What motor do you have, and what drive?

I take it you´ve figured that you will be fabricating new front motor mounts and cutting new holes for the tailpipes. I used the pieces I cut out (with a 4 1/4" holesaw) to fill in the old holes and then made plates to cover them.

A one inch shorter lower will wake up that 24 Outlaw. I know of a guy who has an old 240 Sport (same hull) and he gained 4 mph with the shortie.

I will be running the Imco Extreme gimble assembly and the Imco sc drive. 500 HP

Maybe running a shorty will require less work, on my part, but what # should I run 1" 2" 3" shorter. what do you guys think.?????????
Wild card is running a 3" rise but with an extension.
I didnt realize you have to raise your motor also, the stellings extention box looks like it comes with a added U-joint Knuckle to accomadate the pinion angle?
Or should i just get the straight extension box with a shorty, and not have to move the engine??????????
any thoughts
thanks guys
Curt

The shorty will give you some extra speed, I´m sure. Buy a 2 or 3" one, and if you get too much slip you can always add a spacer.

Because the water leaving the back of the hull does not run at the same angle as the hull itself, the height of the drive on an extension box must be different to that of a drive directly on the transom.
The 3" lift on my box is probably similar to a 1 or 2" shorty without box. But whether I´ve reached the optimum, I don´t know, yet.

The extension box adds other qualities to the handling of the boat, literally making it behave like a bigger boat in rough water, and amplifying the steering and trim inputs, so that you can place the boat how you want it. It feels like a race boat, and I love that!

I looked at the Stellings box before I bought, because the adjustable x and the use of the original motor mounts obviously appealed. However it uses an extended driveshaft with a bearing carrier and two extra universal joints to achieve this. Another place for something to break, in my view.
The Imco is so simple, and this is probably the reason that you see it on so many race boats. I love it.

An unexpected advantage is the access to the motor, and anything below it, like bige pumps and depthfinder. An impeller change is almost enjoyable, sitting next to it and not hanging like a bat!

The 3" lift box uses the original bravo transom holes, and the inner transom has the lugs for the motor 3" higher so you only need to make front motor mounts that are 3" taller. I made beefed up ones, with 8 thru bolts instead of 3.

Learn from the racers, I say.

Something I will add- when you compare the Stellings box to the Imco box, (after having a stellings box and comparing it to a Imco box) the Imco box is a better set-up. With the stellings box you end up with a 1 foot long driveshaft bolted to the flywheel with no coupler/no cushioning effect,you can go up 1" but to go up 2" you end up with a 7 or 8 degree angle which is too much for a high rpm driveshaft so you still have to lift the motor. With the Imco box you have a inputshaft that goes all the way thru everything thats about 15" longer than the stock,it actually gives you some torsional cushion and still uses a merc coupler. I have heard of guys using the stellings box with a Imco input shaft too but overall the Imco box is less money,easier on your drive and easier to set up. I don't know what a Imco box weighs but the Stellings box is really heavy and I'm not sure thats neccesary either,Smitty

I HAD AND HAVE A NEW 2'' SHORTIE on my baja 24 ol which I have owned since 90 I was running 83 at aprox 5800 to 6000 rpm with the shortie with 670hp late summer last fall you need full steering not add on:rolleyes: you will fight chine walk like mad. so full, I might get a box this winter since my boat is a part after theft:angry-smiley-055: in march and yes you do have a pad. I just got in a new plished shortie 2'' I will go with a standard box a 2'' plus 12'' back = to a 1' lift. I was happy with the 2'' but might go to the box I wish it the box came in 1'' 2 '' also the standard should work too. art

Good point about the coupler, Smitty. The Imco really is just an extension of the basic Bravo engineering, and as such, is foolproof. The Imco box is pretty much just a hollow aluminum casting with a few strengthening ribs. It still seemed heavy enough, but when think the forces it carries.......

Thats a difficult call with the 3" or neutral box. If you go too high, you can drop it down with a 1" or 2" spacer, and you definitely need at least 1" lift just to counter the effect of the box pushing the drive further back and into "deeper" water.
I reckon it is this that has caused many to have disappointing results with the box. If you go back, you´ve gotta go up too. How much depends on alot of factors, and it all changes again, when you add some more ponies!

I still reckon, this is a Powerboat test that alot of people would want to read. No trick, 27 foot base boat with a 525 and a three, four and then a five blade prop tested. Then add a shorty and test the props again, A box and the standard drive, then the shorty.
Wouldn´t that be great.

Wild Card,
I got a drive coming with a 2" shortie on it, you still recommend at least a 1" rise box???

and if so, do i still have to raise the engine also??????

I guess I'm some what confused, when you raised the engine with the new motor mounts and new holes for the exhaust, did you also have to move the transom essembly also??

Stock set up the drive shaft comes out of the drive straight into the coupler.
with the extension box , the bearing is just set higher in the box to keep the shaft straight i'm assuming.
thus brings me to see raising the engine, but what about the back of the engine where the engine sits on the inner transom plate, how do you raise the engine there.

Also what did you use in you engine compartment, did you gel it red, or did you clean it and paint it????????? It looks great. I two like alittle flash with my get.

again thanks for all the great info guys
Curt

The 2" shorty will put you in the right direction, with or without box. However, over here, no other 25OL or 27 foot boat runs as good as mine in the rough. That alone, convinces me that the box is the way to go.
There is only 3" and a neutral box to choose from.

You could possibly acheive great results with a 3" lift box and the shorty, maybe needing to fit a 1" spacer and play with 5 blade props to get the slip down if there is too much. You would have minimised water resistence and you´ll see a roostertail like raceboat with Arneasons. High risk, high gains to be made.

Please measure your propshaft to pad dimension (or bottom of bravo transom or cutout in transom, if everything is stripped out) so we can see where you are to begin with.
I feel that I could go another inch up on my settup, and still have a boat that pops out of the hole ok. i went from 6 1/2" down to 4 1/2" prop to pad, with my box installation.

this is how the 3" lift works: the box is bolted onto the original Bravo bolt pattern on your transom and uses the unmodified cutout, Inside the boat an Imco inner transom bracket replaces the Merc one and has the motor mount lugs cast into it 3" higher than stock. At the back of the box the Bravo transom bolts on in a 3" raised position.

The extended driveshaft which replaces the stock Merc one goes through the transom cutout exactly 3" higher up than in a stock installation. There is no bearing or carrier in the box at all. lThere´s plenty of space around it for the hoses and lines to connect up the drive. The access hatches on either side of the box almost make instalation and maintainance easier than on a boat without a box!

Actually, I couldn´t find a bilge paint in the red I wanted, so I used a single component enamel based waterline (the bit where the antifouling meets the side of the hull on a cruiser!) paint. It said it was resistent to oils and water immersion, and it is. I sanded down the compartment with a disc sander and used a primer paint first of all. It is worth it. Once the diamond plate and and the motor went in, it was amazing.
It still looks immaculate after one year. I never, ever want a white engine bay again.
I have a full artillary of concealed blue LED lights in there and the effect, at the dock is nearly as good as when I start the motor up!

Your project sounds great, and you are right, we seem to enjoy the same driving style, giving the expression "airing it out" new meaning!
Stephen

I measured my propshaft to pad and it is 10 inches, or from bottom of hole to pad is 6.5 inches.
this is from my old drive, not with the new 2" shorty drive.

Wild card,
where did you get the red waterline paint??????

these are some poker run pics last summer

Ten inches?! That drive is buried real deep! That was how it was, back in the days of three blade aluminum props and mid fifties top speeds. The 24 hull goes back to the mid eighties, even though your boat is a 1993 example. It ooks great in its original graphics, by the way. Classic Baja!

So now we are looking for 80 mph performance, and although the pad is very small (maybe 1/2 the width of that on a 25OL or even a 272) I think the basics of raising the drive to reduce water resistence will be similar to later hulls.
The pad does not create more lift at the transom, as some think it does, because it actually climbs toward the back of the boat. At best, it is horizontal as the bow lifts at speed.
The narrow pad, and the lack of transom notch mean the shape and character of the flow over the drive and prop is different to mine.
However it does look like you can raise the drive quite some way without getting into massive slip and holeshot problems, because a good four blade will provide you with enough grip near to the surface, especially if you get some distance between hull and prop.
My recommendation would be to go with the 3" lift, together with the 2" shorty, and you will still have your propshaft 5" below the pad.
No need for a five blade, yet!
Call Ron, at Imco, Nevada and get a second opinion. He was a great help for me, two years ago when I was researching my project.
If anyone has put an Imco box on a 24, he will know.

The paint was called Hempels Brilliant Enamel, and the colour is 50800 red. I think this is the same product, now called Hempalin Enamel. Hempels appear to be available in the US.
http://www.hempel.com/Internet/ineco...9?OpenDocument
The description even suggests the products suitability for enginerooms. The grey primer that I used is also listed.

Sweet I'll call Imco ASAP and get some info on the extention box.

This is going to be a fun project wildcard.
I'll let you know what i find out.

Your engine will raise up 3 inches so be sure you have room above it so as to not hit the hatch.

The 24 has about as much headroom above the standard motor installation as a 25. There is acres of it. With my raised motor, I still have enough space for a Whipple on a good sized chiller:cool-smiley-011: :cool-smiley-011: :cool-smiley-011: .

If you get the 24 to run like my 25 does - and I`m sure you will - you will love it...........

Wild Card, nice photos. I like the attitude of your hull and how it sits on top of the water.

FYI for anyone reading---it takes A LOT of testing and $$$ for all these combos. Here's what I have experienced. I have a twin engine boat (32' A/T). My boat originally had TRS drives and I immediately removed the TRS's when I bought my boat and installed XR drives with Stellings extention boxes and I used 32" 4-bladed Bravo One props. However, when I removed the TRS drives---which by the way requires a tranny, I left the engines in the same spot. I did NOT moved them back and just used a longer driveshaft between the flywheel and the bearing carrier flange. I liked how my boat would ride across the water---nice and flat attitude, but it seemed a little too bow heavy even with trim. The bow seemed to stick to the water and just didn't sit up on top of the water the way it should for a boat like mine.

So, I had the hull checked and found out I had a pretty good hook going on that I had removed, and then we moved the engines back to a stock bravo installation to try and get the boat to ballance a bit better in hopes that the bow would sit up a bit more.

Once we did that it DID lift the bow a bit as we hoped, BUT now the boat would not ride in rougher water as well and wanted to chine walk above 80mph and I could not control the chine walk without running the K-Planes in the water a bit which had a negative effect on the speed. So, I HATED the how the boat handled and about the best I would see is about 87-88mph.

The stock length Bravo ones (no nose cones) prop shafts I had sat about 3.5"-4" below the hull. I also thought adding some nose cones would be a PLUS. An option I felt would work well was to add some IMCO -2" shorties with their noce cones already casted into the gear case---so, we installed them. The boat was VERY difficult to get on plane with a 4-bladed Bravo one prop, but once on plane I noticed how well the attitude of the boat was and how it would ride across the top of the water and the chine walk had gone away , but I lost about 10mph in the midrange and no gain in top end speed.

So, I installed a pair of new 30" P5X 5-bladed props from Hydromotive----the boat popped up on plane no problem and I picked up most of my midrange speed again and gained a minimum of 4mph at WOT, but now I really like how the boat rides across the water---on TOP of the water with a different angle of attack and new attitude...just a very BIG improvement on handling! I think the P5X props from Hydromotive helped lift the transom of the boat on top of the water as well. I wasn't really expecting it all (-2" shorties, 5-bladed props) to be as good as it all turned out.

I am very happy with the results,....but for the extension boxes, -2 IMCO shorties, P5X props I spent AT LEAST $9000+ per drive/side!

A friend of mine has a 32' A/T like mine. He has 556cid engines with 8-71 superchargers---all rebuilt, new hydraulic roller cams, ported Dart PRO-1 heads, and added some Stelling large extended primary exhaust manifolds with 5" dry pipes and supposedly made 815hp on the dyno---engines were fresh this year. We ran against each other about 5 times last weekend in South Haven---with air temps and humidity that day we ran dead even at 91mph that day. Even in the mid range he could not pull away from me as we headed up to the top of the RPM range. We both were turning 5400rpms that day. I believe one of the ways he could not pull away from me with my 565cid naturally aspirated engines is because of all the equimpment I have hanging off my transom---which he doesn't have, but with same identical boat, I still expected him to beat me badly with his supercharged engines---all in fun.

MY 24 OL LOves the 5 blade.
I have 25 labbed high five and my boat handles like a dream, cornering, hole shots, mid range pull, and alot of transom lift.
It always felt like i was on a pocket of air.
When i would jump the boat it would land in the water and it felt like it would spring back up.

Wild card is right, my 24 OL has the deapest engine compartment. I needed to do some measuring with the hatch closed one time and i got in the engine compartment , closed it and still was able to crawl from side of the engine to the other.

KAAMA, it sound like you have a real nice set up now. But as you well know men in general are never satisfied with anything to long. WOMEN, HORSEPOWER, SPEED, It's a tragity but HOLY SH*^><""*%# is it fun.

My quest for bigger and better things will never end. My 24 OL is only the start of my long list of (HELL ON WATER) that i will have in the future.

thanks again for all the great info guys
will talk soon

@KAAMA - good post, and interesting results. I admire anyone who has tried so many alternatives on a twin rig. Its really interesting to see what different settups do, and you´ve highlighted an important issue that is good to remember, that it is not just the top speed figure that makes a great boat! If the price is too high to get the last couple of miles, then they are not worth it.

Good recreational boating is generally a mixture of many different experiences, and finding your top speed is only one of them.
However......
In that fabulous movie "The worlds fastest Indian" where Anthony Hopkins plays an old retiree living in New Zealand in the sixties who only lives for his hotrodded and modded 1929 Indian. He still has an eye for the ladies but most of all, he wants to take to the Bonneville salt flats to find out "what she will really do".

As he works in his workshop, the neighbour´s son is often there, asking him the sort of questions only a ten year old could ask.
At one point, wanting to justify his seamingly pointless infatuation with speed, he says to the youngster something like" if I spend five minutes of my life at my top speed, I will have lived more than others have done in a whole lifetime"

........and that made me smile alot!

I must admit, I was almost going to remove the -2" shorties and re-install the stock length lowers and just add some nose cones to them because I didn't think $8000 for the shorties and another $2200 for the 5-bladed props was worth the minimum of a 4mph gain---especially with a loss of about 3-4mph in the midrange because that is where I cruise at 99.9% of the time.

I will tell you the truth, the ONLY reason why I kept the -2" shorties and 5-bladed props was because of the BIG IMPROVEMENT in handling I experienced after the installation! At that point it I felt it was worth the $10,200. The way the boat handles now is awesome. :party-smiley-048:

I suppose if I were to add some 32" 5-bladed P5X's vs the 30" P5X's I now have, then perhaps I would regain all of my midrange cruising speed back as I once had with my stock length lowers and the 4-bladed 32" props I used with them.

By the way, the 30" P5X's I now have on my boat are STOCK/UNTOUCHED props...they're NOT labbed!!!

Wild card do all XR drives come with a different prop shaft size.
I was just thinking about that cause all my props are for a bravo 1
Now, If they do fit with the setup im going for, do you think I will be running the same pitch as i was stock????
If not what do you think I'll have to upgrade to.
now i'm running a 23 labbed and a 25 labbed high five. The 25 has cup taken out and the 23 has cup put into it. I would say that i'm running a 24p with the 23 mirage at 5100 RPM, and the high five i spin about 4850 RPM.
I would like to be about 5200 - 5300 RPM when finished.

Also i was running a 1.36 drive and am also running the same gears in the new XR. I've been told the gears in an XR are 1.35 VS 1.36 in the Bravo 1.
Is this true???????

Part of the beefed up internals of an XR is the 1 1/4" propshaft.

Do your props haft solid or welded in hubs?

If not, it will be no problem getting the XR hub from Mec racing. However they are expensive ($140). you only really need one, as the prop should slide on it easily.

I haven´t had any need for a 1:36 drive, as I was told that they really become relevant on boats running 90+. So I couldn´t even tell you the exact ratio.

It may not be to your advantage, but shouldn´t hold you back either, as the 23 - 26" pitch range is quite efficient.
But there must be a prop specialist here who will be able to say more about that.

imco box
 

I run a 24 degree , 24 ftl non step old school rocker bottom with an Imco 3 inch box and 2 inch shortie . The propshaft is still 1.25 inch below bottom , I run a new Hydo quad 4X -28 , non labbed , by the way out performed all around compared to labbed bravo one , pitch for pitch .Boat will never blow out , I'm going to redrill transom and go up 2 more inches . Any thoughts ?

Well Its Done
 

I finnally finished the the boat, Im going to post some pics this week, before it goes back into storage for the winter.

i went way over board and pulled all the stock rubber hose of and put all stainless braided lines with AN fittings on everything.

diamond plate aluminum (thanks wildcard) on the floor, new carpet, all aeromotive fuel system, hardin marine billet water pump, full twin ram hydrallic steering, two chrome coolers that cool the engine oil, drive oil, power steering, and the fuel.

It has been alot of work but it turned out very nice.

not to mention the $22,000 it cost to do it all (parts only)

Now the question is, HOW DID IT PERFORM??????????????

Well i'm not sure yet, 100 new fittings and alot of leaks to tend to.
Flirting with fuel pressures.
Differant props.

and now its going to get down in the low 40's this week, kind of put a damper on working the bugs out.


But it is faster, how much is yet to be determined.
I'll post some pics soon.

@activatorf1, what power are you running, and what speed and revs?

@laxbaja, congrats! Hope you find what you´re looking for. Did I miss something? Did you fit the extension box? level or 3" lift? What is your propshaft to pad dimension, now?

5100@80 mph . Propshaft is 1.25 below a very , very tiny delta pad . It never blows out and can start out with trimmed out

11% slip is an amazing number for such a high x. I thought that an x like yous only works on 90+ rigs. What weight does your boat have?....and what power?

I'm considering the extension box deal -possibly next year sometime.
I don't want to raise the motor though. I was thinking a straight extension box with no rise, combined with a 3" shortie. Seems like a more simple swap. (less work and fabricating).

Could also switch to the sportmaster lower.

Everyone says the sportmaster lowers don't do much until your into the 90's, but my experience with outboards saw a speed increase in the upper 70-80 range. Was a very lightweight (and massively overpowered) boat, but the speed increase was significant -2-3mph+. It's hard to believe a nosecone or sportmaster wouldn't result in at least some gain on the baja.

what box did you use? a 3'' plus a shortie, I told you my ol worked good with a 2'' shortie, my height was 7'' before and now 5'', I might put a box on this winter but hate to recut the hloes again did it once:D well at 40 out it should run even better.:D art for props see BBLADES there the best

2'' shortie 670hp 83.2gps ran out of prop at 6000:Drpms but the dry pipes sound nice at 6000rpms. well what box did you go with and what drive a shortie?? pics pics, oh congrats Iam thinking of all so painting my ol this winter something wild if I come up with the money. art

I wish someone would try the box on a 24. I hate to be the guinea pig. Wildcard loves his but a 25ol is a very different boat than the 24.

laxbaja PUT A BOX ON i THINK, I have a 2'' shortie only and that gained 3 to 4 mph, so I hope we see some pics here which box, art