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roadtrip se
10-08-2002, 11:06 AM
Many of you have asked me about the decision process I went through and where I got my new shortie drive. One route is to order the case and install your own gearing. I wanted the XR/XZ prop shaft for strength, so I wanted to trade my bravo lower. IMCO doesn't take trades, but some of their dealers do, so I chose that route. Also, IMCO doesn't discount off of MSRP and their dealers will!

I used Total Marine and Performance in Lousiana, Stephen Emmons, because they gave me a
better trade on my bravo lower. They also sent my shortie poorly wrapped for shipping and
pre-scratched. They were no help when I asked them to rectify the situation. I pulled some
strings and IMCO fixed me up. Stephen's number is 985.649.9888, but I wouldn't use them!

Sterndrive Specialists in New York is the other place I shopped. An old Fountain buddy of mine
used them to install a couple of shorties on his 35. He was and still is very pleased with them.
I didn't do business with them, because they weren't willing to give me as much trade on my lower. They have an excellent reputation, but I would ask what they do to protect against shipping disasters! Contact is Chris Martin 315.676.2979.

Installation is an hour at most. Toughest part is mounting the stainless steel cavitation plate which takes a few drilled holes. I also mounted a Simrek drive shower at the same time, so I drilled a hole in the cavitation plate, before it was mounted. If you chose to go the install your own gears in the IMCO casing route, I would pay a pro, because there are special tools and shims needed to do it right!

I chose the two inch, polished shortie mainly for looks. Word on the street is that the brushed finish is faster in the water, but they do tend to dull with use. A little Mother's mag polish on mine and she looks great.

http://www.donzi.net/photos/tsomerville34.jpg

Performance is awesome, although I can't give an absolute number because we did the motor at the same time, the street says 3-5 mph gain. Cool rooster tail too!

With a higher drive, you can turn bigger props.
I am in the process of testing Mirage, Bravo 1, Hydromotive Quad IV, and Hydromotive P5 props.
Of course Baxter has made it more complex for me by insisting that I try both left and right hand rotations. As I said before here, the P5 is unbelievable right out of the box. Great hole shot, acceleration, and grip. I will post final prop results here once I complete testing in the next few weeks.

Anybody considering the shortie route, GO FOR IT!
Donzi's have very conservative X dimesions and this piece really wakes the boat up!

Todd

clayman
10-08-2002, 11:17 AM
Todd, Looks great! It was nice seeing you two again this weekend. Can't wait to go for a ride sometime!
James

Greg Maier
10-08-2002, 11:55 AM
Does the shortie give you less bow lift, almost like a surface drive? If so, how do you compensate for the decreased bow lift?

BERTRAM BOY
10-08-2002, 03:56 PM
Thanks Todd
BERTRAM BOY :D :D :D

Bryan Tuvell 33ZX
10-08-2002, 04:43 PM
Todd, looks great.
We spoke with IMCO this past spring.
Thought I would share what IMCO told me when I called them and see if I can get any other info, they said the 26ZX would see no gain on a shortie, if the bottom of my hull to drive shaft was less than 7" etc. My hull bottom to shaft center at zero trim is 5".

Any ZX guys ever tried these? Cheap gain on speed for the return with a trade, but I surely would not try it untested etc.
Bryan

Greg Maier
10-08-2002, 08:47 PM
That looks ALMOST as good as a Blackhawk roostertail !

Greg Maier
10-08-2002, 09:02 PM
Well, let me know when it is dialed in. We can get out a tape measure and compare the lengths of our roostertails :D :D :D

DonCig
11-04-2003, 07:24 AM
Todd and All, I have a couple of questions to ask concerning the addition of a 2" IMCO shortie to my 1997 Classic 18 Bravo 1 350 MAG MPI.
1. Time to plane speed? Does it take longer to get on plane with a shortie, and what success do you have in pulling an adult male up on a slalom ski?

2. When on plane, does the IMCO have any effect on wake size?

3. Does the boat loose prop contact in rough water sooner than with the Bravo lower unit?

4. In sharp turns does the prop cavitate earlier?

5. Do you normally gain mph?

6. Does the IMCO make a difference in the prop pitch that you can push. I currently turn a 25P Mirage Plus to 5,000 RPM or a 24P Hydromative Quad 1V.

7. Do you need to use a smaller diamater prop, is there still enough clearance to use a 15.5" dia prop?

8. Is there any reason to go with a 3" IMCO shortie?

Thanks,

Don
http://www.donzi.net/photos/untitled.bmp

roadtrip se
11-04-2003, 08:40 AM
Dons' Mile High 18:
Todd and All, I have a couple of questions to ask concerning the addition of a 2" IMCO shortie to my 1997 Classic 18 Bravo 1 350 MAG MPI.

1. Time to plane speed? Does it take longer to get on plane with a shortie, and what success do you have in pulling an adult male up on a slalom ski?
Yes, it does take a little longer to get on plane but I would say only a few seconds longer. Pulling a skier should be no problem, but I'd leave the drive tucked in or they are going to get really wet!

2. When on plane, does the IMCO have any effect on wake size?
Your wake will get longer with the rooster at higher speeds, width and heighth shouldn't make a difference.

3. Does the boat loose prop contact in rough water sooner than with the Bravo lower unit?
Yes.

4. In sharp turns does the prop cavitate earlier?
I haven't noticed this, but I think this issue would have more to do with the driver.

5. Do you normally gain mph?
Yes. I have been told 3-5 mph with no additional modifications. I am running 10-12 mph, but that included a 500EFI.

6. Does the IMCO make a difference in the prop pitch that you can push. I currently turn a 25P Mirage Plus to 5,000 RPM or a 24P Hydromotive Quad 1V.
I replaced a motor at the same time, so my results were pretty dramatic. But as an example, Donzi ships their 500EFI boats with a 25 pitch Mirage and I run with a 29 Mirage.

7. Do you need to use a smaller diamater prop, is there still enough clearance to use a 15.5" dia prop?
I also run Hydromotive Q4 27 and 28 inch props which are 15.5 inches without a problem. They are actually the best overall prop for the boat with much better handling and acceleration. The 27 Q4 turns the same top end as my 29 Mirage.

8. Is there any reason to go with a 3" IMCO shortie?
I looked at the 3". I turned away, because the upper part of the drive has to be modified which means more $$$. The 2" will bolt right up.

One more piece of advice. I bolted up an XR lower to a stock Bravo upper. I have since replaced the upper due to failure with an XR upper. I would go with a stock lower to match your stock upper to avoid the gear stress.

Let me know if you have any additional questions... Happy help out... Todd

Thanks,

Don
http://www.donzi.net/photos/untitled.bmp

Rootsy
11-04-2003, 09:34 AM
Todd,

how far is the propshaft C/L below the keel with your setup? 6 inches?

on the 16 and 18 setup with the same X the bravo / alpha Propshaft C/L is 8 inches below the keel.


Don,

just for comparison sake.. and kind of apples to oranges other than prop position in the water... the alpha SS puts my propshaft C/L at 5 inches sub keel. turning the quad IV and the smaller quad IV O/T i have no issues gettin on plane. i do not hammer onto plane either since i like my SS too much to go destroying things. i have gingerly done it once or twice with no noticable difference between the gen II and the SS.

the only time that i ever see any ventilation is when i do not trim in coming out of a turn and pour on some power rather quickly... even the quad IV will ventilate.

I would think that you would get comparable results with the imco on your 18 if not better @ 6 inches vs 5 sub keel.

Having been in an 18 / Alpha SS combo it has no issue pulling skiiers and tubers. NO blowout getting on plane... handling and performance are superb... same X dimension as my 16...

heck all said i want to be another inch shorter!

Root :)

terry
11-05-2003, 04:37 AM
:D ROFLMAO! :D

MOP
11-05-2003, 07:52 AM
Todd that drive to a guy is like a 5 carrot ring to a gal it is gorgeous, has to one of the best I have ever seen. That being said, what you said about burnished being faster is kind of close to my heart. I like a few others up here were at one time fairly serious Blow Boat racers. Me for one as soon as Stars & Stripes demonstrated that a rivulet bottom was 2 tenths of a knot faster stopped sanding my bottom till looked like a babies butt. It did make the boat faster, but at very low speeds. I wonder if it really makes any difference at higher speeds??? CDMA where are you? Again drive looks great and ride attitude is poetry in motion!

roadtrip se
11-05-2003, 12:01 PM
Opening my address book and putting a little black mark next to a certain Canadian's name..

So when you coming through on that USA tour?

We've got a room in the barn reserved for you, but don't expect to get much sleep...

eek! eek! eek!

Todd
Godzillapedes were nothun..

oldLenny
11-05-2003, 12:41 PM
:D May sometime... :D

As you know, I can sleep anywhere. Bugs are another story...

When is your snow gone? usually.

oldLenny
11-05-2003, 05:39 PM
Poodle, here is something waaayy off topic, but a buddy here, just got back from Ft. Lauderdale and said that there were spiders that made their webs between the telephone cable and messenger to the secondary power lines and in these webs they caught "small birds and giant insects" and ate them. He said they were as big as a hand...Is this true and what are they???!!!! eek! eek! eek!

harbormaster
11-06-2003, 07:35 AM
But when trained correctly, they make good pets. OR At least thats what we do down here...

Rootsy
11-06-2003, 09:24 AM
dont worry lenny, i have a firearm for every occasion :D

But i do find the bow more challenging and gratifying... wonder if there is a P&A catagory for tarantula wink

Root - Kill it N grill it

pmreed
11-06-2003, 10:16 PM
Actually guys, it's a Golden Orb spider or more commonly a "Banana" spider. Yeah they're big, and yes, their webs are big enough and strong enough to occasionally trap a bat or small bird, which they don't eat, by the way. But their bite is nothing to fear. Nothing worse than a large dog.... :p kidding.

http://www.donzi.net/photos/pmreed050.jpg

Here's the lady in all her finery.

Phil

Pismo
11-20-2003, 11:11 AM
RoadTrip......

Did you finish your prop tests on the IMCO shortie? What worked best?

Looks like a 22 classic, what is the engine and how fast were you running before?

I like the hydraulic steeering as well, it must help with the IMCO.

Thanks very much,

SL

roadtrip se
11-21-2003, 01:36 PM
Pismo:
RoadTrip......

Did you finish your prop tests on the IMCO shortie? What worked best?

The prop search is never over. I like trying anything new. Currently, the Hydro Quad4 is my favorite for overall performance. Intend to try the Turbo TXP again in the spring.

Looks like a 22 classic, what is the engine and how fast were you running before?

22 Classic running a 500 EFI. Boat came new with a 502 and ran 68-70. Boat now runs high 70's or low 80's on a great day.

I like the hydraulic steeering as well, it must help with the IMCO.

Hydraulic steering is the only way to go over 70!

Thanks very much,

SL