Thanks for the comments Dustin,
    The RD-1x was designed with plenty of margin in mind but keep in mind the original target was a normally aspirated 13B.  50% more for 20B applications wasn't too much of a stretch but there are a few known places where anything above that is approaching the estimated limits. The shear pin that links the sun gear to the input shaft and the rubber dampers come to mind.  The shear pin can be made larger but the dampers are a bit more problematic for reasons that are too long to go into here. 

Also keep in mind that mind that these drives were not subjected to an exhaustive mechanical analysis which I've always tried to make clear to builders.  Many builders have asked if the drives have been tested to FAA Part 23 standards.  The first answer is a chuckle and the second is that if you expect that standard to be met, do not use these reduction drives. 

Bottom line is that the exact mechanical limits are unknown.  This is definitely Expermental aviation.

Tracy Crook

On Sun, Nov 21, 2010 at 9:51 PM, Dustin Lobner <dmlobner@gmail.com> wrote:

Tracy - awesome, that sounds great.  Thanks for designing a flexible product.  I know you probably didn't have nitro in mind when designing that feature, it's nice that it'll work though. 

While we're on the topic of nitro Tracy, how well do you think your RD-1C will stand up to the occasional 350HP burst?  I do a lot of mechanical testing at my company and actually generate a lot of the AGMA curves that our company uses in aircraft hardware, I just don't know how they get applied by the designer.  I'd be planning on a teardown after a shorter than normal amount of time.  If I do go this route, I plan on keeping a log of nitro shots and have each one count towards half an hour or an hour of PSRU lifetime.  Does that seem reasonable?  What time would you recommend, or any feelings on the matter in general?

Ken - What model of NOS kit do you have?  I went to their website and it seems to be broken out by car type and whatnot.  Some sort of a generic kit, or was it a custom setup?  Thanks!

Dustin 

On Sun, Nov 21, 2010 at 2:58 PM, Tracy <tracy@rotaryaviation.com> wrote:

I think Ken is right that the EC3 would work fine with nitrous but to be on the safe side you could set the B controller up with less ignition advance and/or disable the trailing coils during takeoff with the nitros shot.   There is a coil disable input on the EC3 for coil testing that could be used for that purpose.

Tracy

On Sun, Nov 21, 2010 at 12:48 PM, Dustin Lobner <dmlobner@gmail.com> wrote:

Ken,

How easy would it be to add it after the fact?  I'm building a Bearhawk, planning to put it on floats eventually, but not right away.  The nitro would be assistance getting off the water, same as you.  If I were to add the nitro when I add floats, how hard would that be?

Dustin

On Sun, Nov 21, 2010 at 11:19 AM, Ken Welter <rotarycoot.ken@gmail.com> wrote:

  I have been running NOS with a 125 hp burst to get my Coot up on the step and out of the water, without it I would just have a boat that could not fly, I think it would work fine with Tracy's setup as the nitrous system adds extra fuel to make up for the extra oxygen, use only the NOS brand system as most other systems are junk.

 Ken

On Nov 21, 2010, at 8:21 AM, Dustin Lobner wrote:

Yeah, I'll put that idea to rest for awhile then.  Thanks!

Dustin

On Sun, Nov 21, 2010 at 6:42 AM, Tracy <tracy@rotaryaviation.com> wrote:

Nitrous systems that I've seen have a completely independent system for injecting additional fuel when the nitrous is on.  The EC3 has no way of knowing anything about the NOX system so it does nothing different.

Tracy

On Sun, Nov 21, 2010 at 1:26 AM, Dustin Lobner <dmlobner@gmail.com> wrote:

Some talk on HomeBuiltAirplanes.com forums brought up the question, has someone ever used nitrous oxide on a rotary aircraft install?  I'm pretty sure a supercub-type plane did that awhile back (on a Lyco) for a super short takeoff roll using a fixed pitch cruise prop (with a crapton of HP at takeoff).  That's close to my application in the end, probably with a N/A 20B, hence the interest.

Tracy, how would your EC3 handle short bursts of nitro?  Would that totally throw the mixture curve, would I need to manual adjust while doing it, or would it auto compensate somehow?

Thanks!

Dustin
Rockford, IL