Bogging during big air loops

[trillian]

Yeah the SK540 has that feature as well but I did not want to enable it whilst testing and tweaking. For the moment I have just pulled the pitch curves for idle-up down to 10.5 but I still have 11.5 in hold.

It may be a moot point anyway if I put a bigger or modded engine in there. It's ever so close though, pretty much handles most of the moves I do, it just feels like it needs that tiny bit more power in reserve. (or maybe I just need to up the headspeed a bit? )

Originally Posted by Rototerrier

Vbar has a nice governor setting that has really made a huge difference for me. Collective Reduction

This allows you to continue to run a high pitch in the event you need or want it. Vbar will back off for you if the engine can't keep up.

Maybe other governors have the same option. Might be worth looking into.

[LoveToFly1]

4 things that can affect this....

Blade Brand/Size
Overall Pitch
Tuning
Gear Ratio

I like Rail blades for my Gassers, they seem to be the perfect mix for 3D flight, and not overloading a motor. I am also flying a TT300VX with a QD pipe though, so mine isn't bogging unless I get in trouble and really over drive it.

I would start with turning the pitch down first, then looking at smaller blades, then the tuning. IMO...

[trillian]

Originally Posted by LoveToFly1

I would start with turning the pitch down first, then looking at smaller blades, then the tuning. IMO...

Well, it looks like I've got a modded engine on the way as a friend here was selling one at a price I couldn't refuse.

Soooooo, correcting the bogging will be, 1. Change engine :-) hopefully that will be job-done. It's a TRM 300 so it should have a fair bit more grunt vs the stock 260.

[LoveToFly1]

Originally Posted by trillian

Well, it looks like I've got a modded engine on the way as a friend here was selling one at a price I couldn't refuse.

Soooooo, correcting the bogging will be, 1. Change engine :-) hopefully that will be job-done. It's a TRM 300 so it should have a fair bit more grunt vs the stock 260.

yes, you are going to be amazed. be sure to get an RJX pipe, and mod it like Tom explains in his thread. that is a big motor and needs a lot of airflow.

now, with that motor, your new worries......snapping blades lol JK....

[trillian]

Just to follow up on this a little bit. I thought before I swap out the engine with the TRM I'd see just what the stock 260 can do and go through the tuning from scratch. Since I bought this heli complete bind 'n fly I had not changed the needles and didn't know where they were set.

When I turned them both in all the way to see where they were set the low was a bit lean, something around 1 1/8 and the high seemed a bit rich, right about 1 1/2.

So I started by getting the low needle intentionally rich and then leaning it only just to the point where there's still a little four-stroking. Then with the high at about 1/38 I did some climb-outs, tried it a bit richer a bit leaner till it seemed just the tiniest bit on the rich side.

So now when I do those big loops, you can hear it is under load but it just keeps pulling.

To me the performance is very close to being on par with an OS .91 on 15% nitro, not a rocket but pretty darn capable for smooth F3C / big air style stuff. Which I think is pretty cool.

The pipe on it is a Hatori BTW, hopefully the TRM will run well with this pipe.

[Doug Darby]

If the TRM is a 300 you will get much better performance with an RJX pipe from Carey Shurley. The hatorie will "work" but nothing like the RJX from Gas-powered-helicopters.com.

[fastflyer20]

If you are flying higher head speeds with the TRM VX300 run this engine richer with the muffler Doug suggested. It will make more power over the entire flight especially in high demand maneuvers. 4 stroking at mid stick is normal then it completely clears out under load.

[gassed]

I have often wondered about 4 stroking in a hover while in idle up...I get that with my modded engines and have never been able to get rid of it, but during full power climbouts it clears up... so I guess thats normal given this happens to top of the line custom engines...

So if my engine, a stroked g20 (up to 22cc) gets me 3.3hp at 12600rpms... would the RJX from Gas-powered-helicopters.com work better than my V2?

[fastflyer20]

I doubt you would see a benefit on the g20, a stock V2 should flow freely enough unless it is getting plugged with carbon.

When working on high rev'ing 27.2 and 29.5cc is where we saw the limits of the V2 and stock RJX mufflers. They did not respond normally to needle changes and would sometimes surge at 13,000 and up. Increasing the flow of V2's and RJX's improved response and power.

You can drill out the center of the internal tip on the V2 to 3/16" (5mm) and run without the reducer if you want to see if more flow helps.