UpdateWith just over 50 flights on the Tempest now I thought I might post an update on things.
I think I've finally settled on a setup I liked.
I initially started with the recommended setup which was the hard dampener inboard and the soft one on the outside with a single shim. This yielded quite a soft head which proved to be very good at hovering.
However, I'm one who likes quite a snappy setup and although the machine was hovering great, it felt like I was trying to compete in Formula One with a pickup truck when it came time to do the aeros.
When I make changes I like to make substantial ones so that I can see a definate difference, so I then put two hard dampeners in, with the .25 AND the .50 shims which is pretty much as hard as I can make it with the parts supplied with the kit.
As expected, I had to raise the hovering rotor speed up to 1580 in order to stop the machine 'mast bumping', however the aerobatics such as the rolls improved a lot and the hovering did not appear to suffer.
However the roll rate still felt too slow for my liking so I removed the standard paddles and installed some Hirobo Freya ones I had lying around. With the brass weights in and the flybar ratio set at 0.75:1 the heli started to get blown with the wind. I then removed all the weights from the paddles and tried again and this time it sat still with a small tendency to fly into the wind which I didn't mind.
Now the roll rate is up where I like it and the aeros have come back up to the standard set by the Vigor CS.
Surprisingly, it seems that the hovering seems to have improved for me too. I think this is because I'm more used to the sensitive setup.
Up until today I have been trying to no avail to get rid of a small vibration in the horizontal fin that wasn't serious but was not really acceptable for an F3C helicopter. I changed from the Hatori to the MPII to see if that made a difference, it didn't. I changed plugs from OS 8s, Enya 3's and Enya 4's. The Enya 4's helped, so I decided to try adding an shim to the engine head to see if that would help. I read the article on Ron Lund's site about shimming the head and decided to add another 0.008 thou shim to the stock one and see what would happen. I was pleasantly surprised to see that the vibration was now gone and I could set the needles properly now. I also did not notice any lack of power that you might expect when reducing the compression ratio.
FYI, I run 10% nitro, 15% oil, 75% methanol on an Enya 4 plug with a MPII.
That's pretty much all I have to say at the moment, with these changes the helicopter has really started to show it's potential for me now. It should be remembered also that setup like this is a very personal thing and what works for me does not work for others, as can be seen by the variety of setups discussed here.
The great thing about the Tempest is making all these changes is VERY easy and straight forward. Changing the flybar ratio is a piece of cake whereas on the CS, it's a major engineering development.