Macs pipes : Which one to buy ?
 

Hello,

I finally made up my mind to order a Macs pipe (apparently the best brand).

Macs sells two kinds of tuned pipes quiet or not. Can u tell me the difference between the two versions (I know one is quiter than the other) ? Is the peaky one harder to set up ? Is the quiet one no as powerful as the other ? If so, how much ?

Thanks for your feedback !

RE: Macs pipes : Which one to buy ?
 

Plain, unmuffled pipe = very noisy
Muffled pipe = acceptable, but still so loud you will get in trouble on fields with noise regulations, especially in high rpm applications
Quiet pipe = is just that, a quiet pipe, most of the time that means less noise than a standard muffler.

RE: Macs pipes : Which one to buy ?
 

The "unmuffled" pipe is insanely loud- works beautifully as long as there is no DB limit where you plan to fly-

RE: Macs pipes : Which one to buy ?
 

Noise may not be in issue... What about performance ?

RE: Macs pipes : Which one to buy ?
 

Run the tuned pipe, if you can....they're not that loud. :D

RE: Macs pipes : Which one to buy ?
 

I'm interested in tuned pipes also. Ive been to the MACS web site and they have three different pipes; Quite, Tuned and Muffled Tuned. What is the difference between their Quite Pipe and Muffled Tuned Pipe?

RE: Macs pipes : Which one to buy ?
 

Money, and noise....I just checked my pipe, and according
to the length....it must be the muffled tuned pipe. I thought
it was the tuned pipe....but it's not. The tuned pipe probably
has no baffling....is much shorter, and is the least expensive.

The Quiet pipe has the most baffling, and is the most expensive.
So obviously it comes down to noise. If you have no noise restrictions....
the tuned pipe will give the most power, and is the least
expensive.

I use the muffled tuned pipe on a long stroke OS pattern
engine, and the performance is great....but the motor only
turns 11,500....and it is pretty quiet. I'm sure the Quiet pipe
would serve well at a field with severe noise restrictions,
but I can't say that the performance would justify the high
price.

All three look about the same externally, the length, the price,
and the amount of internal baffling are the differences.

RE: Macs pipes : Which one to buy ?
 

Dave, I must infer from your previous post that the muffled tuned pipe is "not that loud".
So the tuned pipe must be even louder then [&o] ... Have u heard any ?

RE: Macs pipes : Which one to buy ?
 

I'm running an un-muffled tuned pipe on the Whiplash/Rossi combo. It pegs out the 140dB max on the sound meter. It is very, very loud.

And there are definite visual differences between muffled and un-muffled tuned pipes. The un-muffled pipe has either none or a very short (1 inch or so) constant diameter center section. The muffled tuned pipes have a constant diameter section a few inches long to house the muffler assembly.

Other than the color, both of these pipes are identical. The black one still has the muffler section, the silver one has the muffler removed.

RE: Macs pipes : Which one to buy ?
 

I'm runnig the straight Macs tuned pipe! I don't think it's that loud alot quiter than alot of the Gassers at my field! Super tiger ninety header and pipe! Tached today 12,650 Static! Motor is settling in!

RE: Macs pipes : Which one to buy ?
 

Just looking at your set-up, I think your header is several inches too long to be "tuned". A tuned pipe that is too long is just a muffler.

RE: Macs pipes : Which one to buy ?
 

True....my long stroke pipe isn't that long....looks like
you need to cut about 4 inches off that header....

RE: Macs pipes : Which one to buy ?
 

It Started out Taching 11,500 I cut 1/2 inch off it went to 11,800 I cut 1/8 inch off it went to 11,900 I cut 1/8th more it went to 12,000 I cut 1/8 more it went to 12,600. I flew it for another 1/2 gallon! This engine is still fairly new! Sunday it tached 12,650! So it's still breaking in! I think I'm done cutting the header long or not! Unless some one can convice me that I should! Super Tiger said this motor creates it's best power at 11,000! Go Figure! I'm running an 11X9 APC!

RE: Macs pipes : Which one to buy ?
 

If you are happy, that is the only thing that matters! When tuning a pipe, the common procedure is to keep cutting until it stops turning faster then just stop or back it back out the amount of the last cut, normally 1/4" or so.

I only commented since in my experience running 90's on pipes, yours looked a little long, but I wasn't running the same engine, pipe, prop, or RPM. My experience has also been that a properly tuned (un-muffled) pipe is a lot louder than a gasser..by several orders of magnitude.

You are right though..if your plane is flying to suit you, you don't need every last RPM. Your engine will last a lot longer to boot.

RE: Macs pipes : Which one to buy ?
 

Amen.....I stuck mine on box stock....Macs said it should
turn 11,400 with a 12-8 Zinger....

....Bingo....right on the money....I never cut it....:D

RE: Macs pipes : Which one to buy ?
 

Mac's directions say the same thing! Cut till the rpm starts to drop then replace the last piece you cut off! It's Running Great and it's been said don't go for broke for fear of breaking it!

RE: Macs pipes : Which one to buy ?
 

What do they mean ? Re solder it, or simply move the pipe backwards ?

RE: Macs pipes : Which one to buy ?
 

You stick the last piece you cut off back in the rubber
connector....to be used as a spacer, between the header
and the pipe. It gets you back to the second to the last cut....

....the last cut was too much....:eek: