BT QSY
Series
EN
QUICK
BTQSYSeries
INSTALLATION AND USER’S MANUAL - REV001B
8
4 - Installation
4.0 - Propellers
The position of the tunnel will depend on the interior
and exterior shape of the boat’s bow.
•
FIG. 1
In order to avoid cavitation in the propeller, the
tunnel should be placed as deep as possible. The optimum
tunnel position will be at least 0.75 times the diameter of
the tunnel from the waterline.
B
L1
L2
A
BARYCENTRE
FIG. 2
•
FIG. 2
The lever effect in the boat is proportional to
the increase of the distance (L1 and L2) between the
barycentre and the position of the tunnel A and B.
• FIG. 3
For greater lever effect prefer position B.
SINGLE PROPELLER
DOUBLE PROPELLER
TUNNEL LENGTH
MINIMUM 1.5 TIMES
TUNNEL Ø
MAXIMUM 6 TIMES
TUNNEL Ø
An increase in the length of the tunnel increases the effect of the loss of charge, decreasing the nominal driving force.
• For a proper use of the thruster, we recommend a length equal to 1.5 to 4 times the tunnel diameter. To limit losing charge, a
ratio of up to 6 times the diameter can be tolerated.
Minimum 0.75
times
tunnel Ø
FIG. 1
