JetChopper30 mono deep v hull FRP

[jose barreiro]

Can it be used for Nitro like a .21 engine ?

would it be legal IMPBA / Namba for Nitro ?

 

[Leo Ho]

Can it be used for Nitro like a .21 engine ?

would it be legal IMPBA / Namba for Nitro ?

Hello Jose,

JetChopper30 nitro NOVAROSSI PLUS 21-5KT:

https://www.youtube.com/watch?v=oqjLXX7h2WA

JC30 is IMPBA, NAMBA, NAVIGA legal MONO and OFFSHORE class. But illegal in deep V class, because of the RIDE PAD, freeboard height less than an inch. Ride pad can be grinded to smooth arc cross section. Then it is deep V legal.

Rgds,

Leo

 

[Leo Ho]

JetChopper30 setup instructions(view from deck, view from transom, view from port):
Drive shaft offset to right by 5mm.
Drive shaft tilt left, form 1.54 degree with the centre line.(adjustment required)
Drive shaft angle slightly negative. Set hull angle of attack to a small positive angle, for stability.
Drive shaft length(Transom to prop. hub) 81mm.
Rudder blade offset to right by 57mm.
Rudder blade length 54mm exceed right bottom plane.
Right turn rudder blade turn angle 11 degree, 8m turn radius.
Left turn rudder blade turn angle 20 degree.
Transom to rudder blade distance 65mm.
Turn fin tip 19mm above the keel.
Weight bias on left side to produce 0.54Nm moment to balance the torque roll(adjustment required).
Upon triming done, uninstall the trim tab.
CG 29% from transom.
The hook near the transom shall be grinded off to make a nearly perfect straight line.

If the above instructions were followed. JetChopper30 shall have following features, desired for oval racing:
Stable full throttle right turn.
Effective left turn.
Perfectly neutral rudder for straight course.
Unnoticeable prop. walk.
Torque roll perfectly balanced.
Chine walk rarely happen.
Jumping rarely happen, if happened, are balanced.
No porpoising.

 

[Leo Ho]

jacodewit

https://www.youtube.com/watch?v=-l085bbxH3M

Joel Mertz

https://www.youtube.com/watch?v=z8WzN4D8eUs

https://www.youtube.com/watch?v=z8WzN4D8eUs

 

[Leo Ho]

JetChopper30, GO .21 3P:

http://v.youku.com/v_show/id_XNDkyNzQ0ODI4.html?from=s1.8-1-1.2