engine rpm , head speed , gear ratio

[vandelescrow]

I am planning to put the YS91SR Long Stroke engine in a Raptor 90 3D and wondering if anyone curently has this engine, what does the manual say the optimum rpm is?

This way when I order the heli I can also order the gears needed. The standard gears that come with this heli is a gear ratio of 8.27:1

Also for a 90 size heli, what is the target head speed? I currently fly 50's so I'm delving into an unexplored arena for me.

Thanks in advance

[heli-cuzz]

I"m not sure about the YS, but the headspeed should be no different than a 50 sized heli.
Run it at 1950 rpm and you'll have a rocket ship. :) I'm sure you can run different headspeeds, but I have a friend that's a TT Raptor rep and he runs his at 1950.

[AaronS]

You are right Cuzz that 1950 RPM is good for a 90. Be aware, however, that 1950 RPM is the top end for a 90, where as a 50 can be spun up to 2100+. I'm not 100% about the power band on the YS, why don't you just call the guys at YS? http://www.yspartsandservice.com/contact.php
see what they have to say on the topic. Let us know what you figure out.

[heli-cuzz]

I'm doing my homework, Aaron. ;)