XR VS IMCO, and the answer is
 

I have wondered, as have probably many of you guys if the high perf Imco gearcase is any faster than a stock XR gearcase.
There probably is no set answer for every boat/engine combination, because there are so many many variables, such as current top speed, hull design, HP to weight ratio, propeller design, X dimension, etc, etc.
I did have the opportunity to test an Imco back to back on consecutive days on my 28" Nordic/modified HP575SCi. With a moderate gear load, heavy fuel load, 1 person, the XR ran 84MPH/GPS @ 5500RPM with a 28" P5-X.
With a standard length (same as the stock XR) IMCO with the same gear ratio (1.50), the boat ran 85MPH/GPS @ 5600RPM.
Conclusions:
I think the Imco is more hydrodynamically efficient, and loads the prop a little better than the XR. The faster your boat is, the more the Imco will help. Subjectively, the Imco seems to handle a little better, and it looks cool as hell.
Is it worth the extra $$? If you're after every last MPH, yes.
If you have other items that will add significant horsepower for the same amount of cash, probably not.
Regards,
Steve

Re: XR VS IMCO, and the answer is
 

Steve,
my thought was that going to the Imco, if it were shorter could provide some decent gains. If you build a new drive, adding the shorty at that time is only a little more money.
And Lloyd said to say hello when I spoke with him yesterday. He said the H2x would benifit greatly with a shorter drive, so that is the way well will head unless I hear some negative before then. I still need to get to Baja and see what they say..

Thanks
Dick

Re: XR VS IMCO, and the answer is
 

are you comparing the imco lower to the sportmaster lower by merc and if you are wonder what would happen if you cut the skag on the sportmaster down like the imcos as it is 2" longer in stock form?

Re: XR VS IMCO, and the answer is
 

Mike,
It's the more common XR case, vs the IMCO, in the same length to compare their hydrodynamic efficiencies.
I'm a Mercury guy, but the I/O Sportmaster has not proven to be any faster in most applications than the XR or XZ. Looks to me like it's a tail lifter, and that's not what you need with most of our boats.
MR Gadgets, Glad you hooked up with Lloyd. He's a great guy.
Because the X dimension is already very high on my boat at 19.25"s, I don't need/can't use a shortend drive. However, on most Bajas, because of their normally conservative X dimensions, the shortened drive should work well.
Regards,
Steve

Re: XR VS IMCO, and the answer is
 

steve my brother and i have the same boats and have bought two sportmaster lowers and one imco shorty lower all three 2" short and we are going to try the sportmaster in stock form with the skag cut down and te imco to see if there is a big difference both boats have farly big power and are well over 90 so that is why i ask the stock lowers with out a good nose cone do not work as good at those speeds on our boats

Re: XR VS IMCO, and the answer is
 

Mike,
If that's your motor in your avatar, then you do need a sleeker than stock gearcase.
The options for Bravo drives seem to be:
A nosecone (like the "leading edge") on the XR or standard case.
A sportmaster.
An Imco.
It would be interesting to compare the Imco to the Sportmaster. I'll put my money on the Imco.
Regards,
Steve

Re: XR VS IMCO, and the answer is
 

I have often wondered what I would buy when I finally destroy my Bravo 1. I know it just a matter of time since I have a Vortech Supercharger on a 502 mag efi. When that day comes I just planned on buying an Xr, mostly because of price, what are the advantages of the imco (not the shorty because thats been tried in Kachina's with no gain) or the Teague or Konrad. What drive is the best (subject to everyones opinion) and what prices do they run? Do you have to change anything other than the drive itself to change out to one of these drives? Gimbal bearings, external steering wing plates? Etc? I have external steering already so I had wondered if the wing plate will bolt up to any other drives.

Re: XR VS IMCO, and the answer is
 

yes that is my motor we think the imco might be faster to but i wont to get them side by side i thank the thing that is hurting the sportmaster is the big skag its a monster hell we cut the stock ones down and they are small comparded to the sportmaster

Re: XR VS IMCO, and the answer is
 

also if i was going to buy a drive now it would be the max machine worx drive i thank the two brothers are kicking exeryone else in the the drive ind. azz no way would it be the imco but i do like there lower case

Re: XR VS IMCO, and the answer is
 

Maxx is the way to go, I've know and heard horror stories from IMCO customer service and quality.