crb76

I am trying to understand the pros and cons of the XR, XR sportmanster, and the XR Sportmaster Shortie on a 525EFI ITS applications. How do you choose which drive to use? Insight please...

Hang Time 27

Someone please add/correct me here....

Just the basics...........

XR = merc Bravo High Performance drive

XR sportmaster drive = bare aluminum racing lower case, also shorter (moves prop up ?? inches), designed for higher speeds.

XR sportmaster shorty = same as sportmaster, but even shorter lower case, raises prop up even more.


Shorter lower cases produce less drag for more top speed, but might require more blades on the prop to hook up for getting on plane or even cruise speed. Using more blades than you need will put more stress on the drive.

As far as strength and durability, they are about the same, with the 525 being the most HP Merc will put to them.........

tblrklakemo

the 600sci being the most power merc will put to them

drejustice

Which would you use on a modified tunnel/cat. i.e. ultra hull which does have the center pod?

tblrklakemo

I think they say if your capable of 80 or 90 + mph you will begin to see the benefits of the SSM. As long as you fit that speed and dont exceed the HP, go for it.

Knot 4 Me

The Sportmasters have a different nose design to better get water to the prop at higher speeds. They also have a larger skeg than a standard XR which can add drag depending on setup. Some manufactures will actually cut down the skeg for more speed.

monstaaa

the standard xr typically is a dual water pick up drive,also available as a low water pick up unit, good to about 90 m.p.h before the bullet starts creating prop blow out and becomes hydrodynamically ineffiecient.

xr sport master is surface pieceing low water pick up only drive. it uses the same internals as an std xr but besides what is already mentioned it has a longer wider skeg. it is the same length as the std xr.

xr shorty is identical to the xr sportmaster with the difference being in the height of the lower only. it is 2 inches shorter resulting in a higher x dimension.

as for the application i would suggest runing a straight edge between the two sponsons at the very bottom of each. using the straight edge as an indicator of water level compare it to your drives bullet hieght. if your around the same you can probably use the shorty sportmaster. if your an inch or so higher iwould sway away from it , fearing you may increase your slipage numbers.
if your runing say 90 or 92 then maybe try the std sport master.

good luck.

zt260

The XR sportmaster is the same length as the XR. Only the shorty is 2" shorter.

Hang Time 27

I was thinking Merc was going to be putting their new drive to the 600-800's stuff from now on.......not so??

tblrklakemo

They pair the xr with everything up to and including the 600. The NXT1 is only available with the 700 right now. I would think you can buy the #6 and use it with the the 525 and up, but it will cost you and will depend on boat manf. Fountain uses the NXT1 transom assembly with the #6 drive when paired with the 700 motor. Im pretty sure the #6 is the only thing offered with the 850sci....the NXT1 drive is only rated to 700hp?