Toe in or not on twin duoprops (DPE)

[A_8]

When I got my boat the DP outdrives was not 100% parallel but toed in slightly. When I look at the installation I can see this was by factory and intentional.

The manual says DP drives should be parallel and single prop drives toed in so I fixed this.

The other week on a IPS presentation at Volvo Penta I was informed the IPS drives need a 2 degree toe in for maximum performance...!?

So now I am confused wrt my 2 DP-E drives, IPS is also DuoProp so should my DP-E drives be toed in or not?

Anyone know?

Thanks/
Michael

 

[rubberduck]

I have a twin Mercruiser duo set up 2007 instalation & they appear to be slightly toe in, if that helps? /forums/images/graemlins/smile.gif

 

[[2068]]

Builders normally set some toe-in to give you that extra 0.5kts when flat out. Something to do with optimum water flow, but it depends on the hull.

I've got DP-E's on an S28, and there is a very noticeable toe-in set.

dv.

 

[A_8]

Thanks,

I wonder what the installation manual says.

My steering became neutral when I removed the toe-in and as far as I remember I also got more speed...perhaps this was because they had to much toe-in to start with.

Anyone know how much might be optimal, 2 degrees on IPS but those are further ahead so perhaps 4 degrees might be good for outdrives?

 

[dalex]

From the VP DP290 manual I quote "In a twin installation the 'Toe-out' angle between the stern drives must be adjusted until an operation free from cavitation has been obtained. Increase the angle between the sterndrives on a boat with a deeper V-hull. Adjust the sterndrives in accordance with the picture. If the measurement at the transom shield is 'A', the measurement at the screw-head of the trim tab must be 'A' minus 15-25mm (9/16-1"). Note! Push the sterndrives apart by hand when measuring."
The picture shows measurement 'A' as the distance between the two centrepoints of the transom shields, and 'B' as the distance between the two centrepoints of the cones on the props.
Hope this helps!

 

[A_8]

Thanks Dalex!

I guess I have to adjust them back again /forums/images/graemlins/blush.gif

/Michael