deletemenow

I'm currently flying a aresti 40 with a 46fx and ultrathrust muffler with 11.5 x 4 prop at 3600 ft. eleavation. The plane is fairly quick but I want it to be faster. I have both a macs pre-tuned pipe and the marine tuned pipe.The plane weights in at about 4.5 to 5lbs.

I have no experiance with tuned pipes but I have read just about everything here at RCU and I'm ready to give it a shot.

Of the two pipes which one would give me what I'm looking for and what prop would I want to tune too? I would like to see more speed. Also do I lose vertical performance to go fast?

Thanks for any help, Ken...........

Alastair

I don't know a lot about tuned pipes, but for the prop you will probably want to go with a 10 x 7. From my experience it gives the best combination of vertical performance and speed. Since you live at high elevation it might make a difference to the prop that works best, but I think a 10 x 7 or maybe a 10 x 8 would be a good prop.

PAINLESS

My Feedback: (19)

You would see an improvement with either pipe.

Regular tuned pipes are quite loud. If one of the pipes you mention is a muffled pipe (has an extra chamber on the end) use that to avoid any noise issues where you fly.

If noise is not an issue use the one that has the most volume, usually bigger in diameter.

deletemenow

Thanks guys,

Well noise is not a issue at our field so I don't have to worry about that. I was just worried about where to start on the prop size. From what I've read here is you tune to the prop and if you change props you have to re-tune. Is that correct???? I just kinda want to know a little bit about what I'm doing...hehehe...
You learn by doing so here goes nothing....later......Ken

ChuckAuger

My Feedback: (12)

Try this..

The UltraThrust muffler is pretty good as far as tuned exhaust goes. You can change props without having to re-tune anything.

Try the 10X7. 3 more inches of pitch ought to give you some extra speed. Yes, you will lose some vertical, but a 4 pitch prop is just about as slow as you can buy, speed wise.

Try a few different props first..you might find something you like, then if you want to go further try the pipe. Tuning a pipe isn't hard if you've done it for a while, but try changing props first.

deletemenow

Yeah I really like the ultrathust muffler. I have been playing with different props. Let me see if I can translate what I thought was going on. With the current setup with the 11.5 x 4 prop there seems to be good speed and excellent vertical (unlimited really), there is a considerable tone difference in the muffler (much louder).

With the 10x6 and 10x7, The speed seems to be much slower and the muffler noise is considerably lower.(It may appear slower due to the fact it is so quite.) Vertical is not to bad but not unlimited.

I tried 11x6 and 11x7 just to compare and it seemed that it maybe was too much. It was like the engine couldn't unload enough to spin the prop where it needed to be. The muffler noise was even more silent. The 11x6 seems to perform the same as the 10x7 but the 11x7 was too much.

Are the audible differences telling me anything?

I'm not sure if I'm going to go much faster with the current motor and muffler combo (46fx and ultrathrust) on a 5lb airplane thats why I was considering the other tuned pipes.

Hey ChuckAuger we met last year at the ARKS fun fly. I was just starting to fly the gas planes. I enjoyed the diamond dust and I believe it was a duelist. The speed blew my mind. Darrell at AHS has told me that if I wanted to start experimenting with speed you were the man to talk too....Catch ya later......Ken

ChuckAuger

My Feedback: (12)

Yeah..don't slow the prop down too much or it will fall out of the RPM range the UT muffler was designed for.

And I met a lot of new faces at the ARKS...do you have a van or something with some graphics similar to your avatar?? I seem to remember something like that.

deletemenow

Yeah your probably thinking of the the bronco....was this it?

ChuckAuger

My Feedback: (12)

Not sure..I just remember some ride there with some graphics..

If you think last year was fast, wait til this year! LOL

Darrell said somebody over there got a Diamond Dust..did they ever get it going??

deletemenow

Yeah that was me....it's about half way built..I've been working on some gliders for some contests coming up so it kinda got shelved...should get back to it this week though...Ever since I saw that on of yours(rip) I had to have one....later...Ken