Stand off box or extension box
06-29-2002, 12:35 AM
#1
Registered
Thread Starter
Join Date: Jun 2002
Location: Burbank, CA
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Stand off box or extension box
I am new to high performance boating, and would like to know what a extention box or stand off box does for an outdrive.
Thanks
Thanks
06-29-2002, 10:40 AM
#2
Platinum Member
Platinum Member
ditto on Troutly's post.
Picture your boat as a seesaw, with the pivot point at the transom. If you trim the drive up, you see that the prop thrust pushed both forward AND down on the end of your seesaw. This down component pushes the stern down and lifts the bow.
Now move the drive off the transom a foot. You now can see that the DOWN component has far more leverage and, thus, effectiveness in lifting the nose of the boat/seesaw. Now, you can either lift the nose more, OR use less trim angle to lift the nose like you could before. Any time you can use LESS trim, more of the prop force goes towards moving the boat forwards.
The LAND & SEA ads for the stern jack do a good job of illustrating how the water cleans up as it gets further away from the transom. (a stern jack is not an extension box, but sort of does similar stuff).
Picture your boat as a seesaw, with the pivot point at the transom. If you trim the drive up, you see that the prop thrust pushed both forward AND down on the end of your seesaw. This down component pushes the stern down and lifts the bow.
Now move the drive off the transom a foot. You now can see that the DOWN component has far more leverage and, thus, effectiveness in lifting the nose of the boat/seesaw. Now, you can either lift the nose more, OR use less trim angle to lift the nose like you could before. Any time you can use LESS trim, more of the prop force goes towards moving the boat forwards.
The LAND & SEA ads for the stern jack do a good job of illustrating how the water cleans up as it gets further away from the transom. (a stern jack is not an extension box, but sort of does similar stuff).
