YS91/700 headspeed

[t-rex pedro]

Hi guys

What H/S are you guys running with this motor? I've done various searches and some say 1850 is optimum and others say circa 1950.

Mine has more power than I ever expected (or my skills require) so I'm not chasing power, more concerned about running the YS at too high a H/S and possibly damaging it.

JFI I'm running Magnum 30.

Cheers

[Steve]

Is it the 91 SR you're on about?

I think the peak of the power curve for this engine is at about 15400 rpm, so on a heli with an 8:1 main gear ratio (i.e. my Vibe), that's a head speed of 1920. Practical rpm for the engine is 2000 - 17000 rpm.

Not sure what the main gear ratio is for the 700, but start from the engine and work it back from there.

[helidriver]

1880 max on an sr.

sounds like u need about 1700.

its 8.2 ratio btw

[mattie-lodge]

Pete,

I'm pretty sure mine is running at 1950 Headspeed. I've not tached it but thats what I set the revlock upto.

[Sesame]

had mine running at 1950, until the ring went, but I really dont think it was being pushed too hard.

[t-rex pedro]

It's about 1950 atm as a clubmate tached it on Saturday. Its got loads of grunt and the backplate is cold to the touch. If Mattie and Tony run at this headspeed then thats good enough for me.

Thanks guys.

[Boggy]

t'rex 250 run at 3500 !! go on you know it will

[moonmanflyer]

i think mine is about 1950 ish and has lots of grunt, but thats with a os91pumped

[0h5h1t]

1900 for me on the align 91hz with MP2. Loads of power, but then i did come to this heli from my trex600 so it would seem powerful.. lol