Does a tuned pipe make a BIG Difference?
 

if so what should i get for a os46fx?

RE: Does a tuned pipe make a BIG Difference?
 

A tuned pipe has a tremendious appeal for many people, especially young newcomers. For a tuned pipe to work most efficiently, it must be used in a primarily high speed situation, also the engine must be run in the upper levels of it's rpm range ( like 15 - 16,000 rpm) with a smaller diameter - higher pitch prop. Also the engine must have some pretty radical timing to utilize the physical properties offered by the pipe.

There are some few exceptions to this as in pattern flying whereas the pipe is also used as rpm stablizing device but the engine is still used primarily WOT.

A tuned pipe to use in a 3D application is a waste of your money. Just use a more powerful engine.

There are people who will show up at the field with a LA40 W/tuned pipe and a 10-6 prop on a trainer plane proclaiming how much better it is. If there was any increase with this setup, it would be absorbed by the extra drag and weight of the pipe.

These people would have gotten just as much extra performance by putting a new decal on the plane?

Enjoy

Jim

RE: Does a tuned pipe make a BIG Difference?
 

it is for a speed plane. I have a laser arrow, i guess its a speed plane. Worth it?

RE: Does a tuned pipe make a BIG Difference?
 

So, you're saying that I would be wasting my money on a tuned pipe? I am building an 80" OMP Profile with a MVVS 2.15 gasser. Primarily 3D flying?

RE: Does a tuned pipe make a BIG Difference?
 

Absolutly!
3d and a tuned pipe. Hello?
Many people mistake muffler pipes for tuned pipes.
The latter has no place on a 3d aeroplane that spends most of its time a low to medium RPM.
Thus off the pipe...thus being pointless.
85% of the folks running a tuned pipe on an aeroplane aren't running a "tuned pipe" at all.
Sure it's a pipe...but it aint tuned!
For that you'll be needin' some serious header cutting untill you reach the tuned point at full throttle.
Then the engine is basically useless at any setting other than full bore.
Unless you're into racing or retro 70s balistic pattern flying...stay away.

RE: Does a tuned pipe make a BIG Difference?
 

I have a Macs Tuend on my 46 FX. I noticed a little differance on the top end. It defanitly spins higer RPM's...

RE: Does a tuned pipe make a BIG Difference?
 

Morris has a mini tuned silencer that I am considering. I agree with the previous postings as a waste for 3D "but, My interest is in the throttle responce off idle. This pipe mentioned is suppose to greatly increase the responce time from idle to full bore which will benefit 3D. I dont have one but like I said Im considering..One other benefit is claimed 1000rpm more which might or might not trip yer trigger..My 46 can use more punch and this pipes lighter also..Walt

RE: Does a tuned pipe make a BIG Difference?
 

Oh, I probably should have added that I have the Single Peice Muffler... Im planning on getting one for my .61 and the smoke system for my U-Can-Do .46

http://www.macspro.com/onepiece.asp

RE: Does a tuned pipe make a BIG Difference?
 

The tuned pipe is definitely for speed. As stated above, your idle to wot time will be reduced but you must understand there is no in between per say! For 3D use a standard muffler or one of the tuned mufflers but there is no need for the tuned pipe. Prop range is of the 2 extremes. for a .46 3D prop is 12x4w and a pipe prop would be 9x9/10x8.

RE: Does a tuned pipe make a BIG Difference?
 

So, for 3D a tuned muffler would or wouldn't be advantageous on a gas engine?

RE: Does a tuned pipe make a BIG Difference?
 

I like my Mac's black pipes and for 3 reasons I believe are 100% correct. 1) They look cool! 2)They are seamless so, no leak potential. 3) The make a great handle when cooled down.:D I'm serious here! There may be a gain in RPM but, I don't think it's significant enough to warrant one on that alone.

Jim, the only engine I saw benefit with the black pipe is, oddly enough, an OS 40LA. A friend has one on a SPAD Debonair that is really heavy, and it just amazes me how well it pulls that brick around! Of course, it may just be my perception. Your mileage may vary....;)

True tuned pipes, as I understand it, can be tuned for a specific RPM. That may be high or mid or even low RPM. Unfortunately, when operating outside of it's selected RPM, a stock muffler will probably outperform it. This is based on reading and transferral of motorcycle technology. I haven't actually done this on a glow engine.

Interesting thread!

RE: Does a tuned pipe make a BIG Difference?
 

I had a OS.32SX Reno Racing plane that was doing about 125mph and putting a tuned pipe on it, whinning it out to an incredible RPM, I was able to tweak it on up to over 135ish....140 with the wind.

RE: Does a tuned pipe make a BIG Difference?
 

Gas motor is different! They benefit greatly from a tuned can. 3D and all!!!

RE: Does a tuned pipe make a BIG Difference?
 

Some of you seem to be confusing a tuned muffler with a tuned pipe? The Morris OSmod1 for OS46FX (and clones) to Rossi Round Mini-Tuned Pipe System is more in the area of being a tuned muffler. $49.95. It has a folded expansion chamber. It's folded back over itself. This might be to advantage to a lot of you? The original Tower 46 muffler costs only $13.99 and is almost as good.

Believe me, the Mac's one piece muffler is not tuned for anything. It's a very nice, quiet, light weight, muffler that doesn't fall apart, but tuned for anything it isn't. I have several and the one for a 46FX cuts the rpm down by 1,000 compared with using the original Tower 46 muffler. With the Mac's muffler the engine is real nice. Needle settings are very stable, there's no in flight quiting, the muffler doesn't fall apart, but the top end power isn't there.

Many more people run tuned mufflers than pipes. They are more realistic for the common man. Though even then, they are more effective at higher rpms than the lower ones. They do nothing to flatten torque curves or increase mid range torque.

By tuned mufflers, I mean things like a mouse' can or poor man's tuned muffler like the original Tower 46 muffler, or ones offered by other companies like Jett or Performance Specialties.

Pipes most often have more bragging rights than performance increase. I hope I havn't offended anyone who has already put out enough money for a pipe to buy another engine or a person who's already learned the truth and is trying to pass his off to some else.

The best way, I guess, is to prove it to yourself with accurate rpm checks and documentation of performance changes? Then you will know what you know and you will not listen to all the other claims. What's all important, is what works for you, even if it's just physiological?Enjoy,

Jim

RE: Does a tuned pipe make a BIG Difference?
 

Ok. I'm getting a little confused. Gas engines are different?
I will be installing a MVVS 2.15 gasser in an OHM Edge profile. The profile is rather large so a pitts style muffler wont work. I cant seem to find anything else with the exception of the quiet tuned pipe system offered by morris hobbies.
Being a profile, I will be performing both 3D and IMAC. 3D performance is my biggest concern. Quick throttle response is a plus. Maximum torquethroughout the entire rpm range is critical?
What do you guys recommend?

RE: Does a tuned pipe make a BIG Difference?
 

My apologies to those of you who use a classic pipe in the manner for which it was intended or those who came across a pipe in a good deal and think it just looks cool whether it does any good or not.

I'm currently, just a sport flyer and have no use for one. I'm around 3D some and know how the engines are used and know that a pipe is not functional on a glow powered 3D plane.

30 years ago we all flew our planes at WOT and the faster the better. In those days, a pipe would have made more sense to me.

I do like tuned mufflers and have several.

There are also pipes sold that have a "less peaky" performance increase and these may be useful for more of us than the old classic tuned pipe? These should be looked at more closely by many of us?

Enjoy

Jim

RE: Does a tuned pipe make a BIG Difference?
 

W8YE.
Ok, I believe you.
Are your opinions the same towards gasoline engines?

RE: Does a tuned pipe make a BIG Difference?
 

John, I have several gas engines of the conversion variety but have no broad experience to elaborate much on them. I have custom mufflers on all of them but do not consider that they are anything tuned. They have more of a exhaust diverter.

There are a few guys at the field with the 3W 150 type engines and I've never talked with them about cans but I thought they had what was considered to be the can variety of mufflers on them?

Now this is just my opinion from watching and listening to these "big guys" but I considered the cans to be more in the tuned muffler department. These engines, however, are never run WOT except for 2 or 3 seconds at a time.

Enjoy,

Jim

RE: Does a tuned pipe make a BIG Difference?
 

Jim, Crash,

...Only high RPM? Wrong!

Please read this about what can be done for an ST .90...

http://www.supertigre.com/engines/supg0235-man.html

...

In 3-D flying you NEED high power to pull out of a hover. If your tuned muffler allows the engine to have a good midrange too, DO USE ONE!
On the MVVS .49, for example, it is great!

RE: Does a tuned pipe make a BIG Difference?
 

Dar, Go back and read what I said and then read your link again... Of the two pipes they used, one was used in F3A which is mostly WOT.

The other one, was one of the newer design Quiet Pipes which I was saying would have a broader torque range than the classic pipe. You will notice, however, that even the Quiet Pipe raised the Torque peak from 7200 to 8000. This pipe could be set up to your advantage in some less than WOT situations for it will really broaden the power band of the G 90. It would require careful selection of prop and airplane.

There are two opposing problems with the G 90 and a pipe. They go on and on in the link you provided about the conservative timing and small passages on the G 90 (giving it a low torque peak). This goes against the grain of any classic pipe theory that I ever read. They didn't mention it in the link but the last batch of G 90's produced in Italy had the same carb on it as they use on the G 40.

I have a couple of G 90's. If you put a 15-8 on one, it will have a peak static rpm around 9,000. It is the sickest sounding engine you ever heard from a spool up point of view. This is absolutely no good in a 3D situation. I'd rather use my Saito 100. Bax recommends a 13-6 for break in on a G 90 which is fine but you will notice that this is not enough prop for the engine because it will spin it close to 13,000 which also happens to oppose the Super Tiger link that you provided. I like the 14-6 on a G 90 for my kind of flying but a friend here locally, (that's also on RCU all the time), needed more speed in his war birds than what the 14-6 at 11,000 gave him, so he went to a 13-8.

As I said before, I think tuned mufflers and Quiet Pipes are nice, and I have several tuned mufflers, but I generally tend to opt for a more powerful engine rather than spending $50 to $100 for a exhaust pipe. A K&B 61 W/ std. muffler weighs less than a OS 46 FX with a Classic pipe and will out do it, performance wise, all across the board.

Pipes are most effectively used in competition whereby there is a displacement restriction. The competitors will use this maximum displacement engine with a pipe (And the Quiet Pipe, multiple chamber, types are most commonly used now days) To gain more power and competiveness in their flying.

In Western Europe where engines are required to have extra quiet mufflers, the classic single chamber pipe makes no sense at all in a none displacement restriction environment.

You are perfectly welcome to use a pipe if you so desire. I only have control over what I do and often wonder if I even do that very well?

Enjoy,

Jim

RE: Does a tuned pipe make a BIG Difference?
 

Hey Joe: To answer your question check out Morris Hobbies. The may have the answer you requested. Walt

RE: Does a tuned pipe make a BIG Difference?
 

I have to disagree with most of what is being said on this thread. I raced glow powered boats for years, all with tuned pipes. Tuned pipes are tuned for what you want. In general the longer the pipe length, the more torque you will get. The shorter the pipe, the more top RPM you will get. If you get too short you lose your torque and the engine won't be able to get going. This is not even considering the design of the pipe. Some pipes such as an Irwin, give tremendous low end power. A Mac pipe is more for top end. A pipe is not useless for 3D. They will all help in the transition and allow you to turn a bigger prop. Just don't get it too short or you will have the engine jumping on and off the pipe, which is no good except for top end. A tuned pipe is always working. When I talk about length, I'm talking about from the glow plug to the high point of the pipe, not the length of the pipe itself. I hope that makes sense. I have used pipes on 46 powered profile planes and they do help all through the throttle range. This has been on stock motors.

RE: Does a tuned pipe make a BIG Difference?
 

Seems for all that has been said, no one has answered your question. Since your intended use is a speed plane by all means use a straight tuned pipe. It does make a sizeable difference even with sport engine timing. If the engine is setup with more than 22 degrees blowdown angle The PIPE makes a HUGE difference. :D

All this talk about differences between Glow and Gas is hogwash!! Exhaust temps and therefore acoustic wave speed are slightly different, but other than that they both operate on the same laws of physics and both can equally gain a lot of power through the use of a tuned pipe.

RE: Does a tuned pipe make a BIG Difference?
 

Jim,

In his second post in the thread, Joe123s specifically wrote that it is a speed plane.

So he does need the full throttle gains.
Most tuned silencers; MVVS in particular, have a very wide RPM operating range.
The .40-.49 tuned silencer will, as it comes, boosts performance in the 10,000-16,000 RPM range, which covers each and every prop you are likely to use with these engines. With the Bolly 11.5x6 I use, you can clearly hear the engine get on-the-mini-pipe at half throttle (not half RPM, though).

A Mac's OS.46FX, ready-to-use, full length pipe, will only be at its best with 10x6 and 10x7 props and with 10-15% nitro fuel.
Change anything and you could be out of the pipe's RPM range.

The Bolly pipe mentioned in the ST test, was to show that this pipe allows the engine to make the same HP at 20% lower RPM.

RE: Does a tuned pipe make a BIG Difference?
 

Test 1. Open exhaust; fuel -- 5 percent nitro, 10 percent castor, 10 percent
ML70 synthetic oil, 1.5 percent ether, and the remainder methanol; glow plug --
SuperTigre. Following the manufacturer's fuel recommendations, I obtained rpm
ranging from a high 16,867 to a sensibly lowest feasible 4,400rpm.

.... [X(]....(Yikes)