Author Topic: Mini Pipe. (Read 2180 times)

Chris Wilson · « **on:** October 15, 2012, 07:43:52 PM »

Any one try a mini pipe plus header instead of a full length pipe on a stunter yet?

I have this alloy mini pipe with a flat disk first baffle, perforated by three holes plus a short tube and upon first look I can't see why it wouldn't work OK.

Thanks.

Steve Helmick · « **Reply #1 on:** October 20, 2012, 07:54:07 PM »

I'd like to see a picture or diagram of your "mini-pipe". Over here, a "mini-pipe" is a short, straight piece of tubing as used on a few classes of CL speed, as decreed by regulations. There are no baffles, just a straight piece of tubing. AFAIK, the events are .21 Sport, .21 Proto, Formula .40, and NW "C" speed, which is a new .40 engine event that allows monoline, unlike the others.

Steve

Reptoid · « **Reply #2 on:** October 21, 2012, 03:31:30 PM »

Steve;
I believe Chris is talking about a muffled mini pipe, I.E. made popular on cars and Helicopters they consist of 1/4 or 1/2 wave mini pipes with a muffler can around them and a small outlet stinger. Some use baffles and others use pipe within a pipe and outlet location is not critical.
I can't give Chris any advice as I personally don't prefer pipes for stunt, and just use mufflers

Chris Wilson · « **Reply #3 on:** October 21, 2012, 04:17:29 PM »

Quote from: Steve Helmick on October 20, 2012, 07:54:07 PM

I'd like to see a picture or diagram of your "mini-pipe". Over here, a "mini-pipe" is a short, straight piece of tubing as used on a few classes of CL speed, as decreed by regulations. There are no baffles, just a straight piece of tubing. AFAIK, the events are .21 Sport, .21 Proto, Formula .40, and NW "C" speed, which is a new .40 engine event that allows monoline, unlike the others. Steve

Hey Steve,
yeah, the 'minipipe' is much like a cross between the buggy ones and a shortened full length flat disk pipe.
(Since I am not versed with posting pics here the best that I can do is to supply the link to the purchase of it -
http://www.ebay.com.au/itm/130777228843?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649)

With the proper header length I am assuming that getting a limiting effect or wall will be possible and the only issue that I can perceive is that the divergent cone is very much shorter than the norm so the negative wave may not be strong when coupled with the added length.

Thanks.

Reptoid · « **Reply #4 on:** October 21, 2012, 09:55:15 PM »

Yes Chris;
Mini pipes work on the same principal as full length pipes, The length from the reverse cone or baffle is critical. the only benifit is reduced size and weight. They produce less power than a full pipe and the overall length for the same RPM range will be 1/2(1/2 wave pipe) or 1/4th(1/4 wave pipe) as long. The volume is also engine size dependant just like a full pipe, so you can't just use a 21 size car pipe on your larger stunt engine. If you stick a random small engine pipe on the end of a long header you will in effect just have a non-power improving muffler. Exhaust system tuning on a two stroke is a science/black art unto itself and requires a lot of testing/tweeking to optimise, even after all the theory is followed correctly.
Hope that helps

PS: The one you showed the link to looks like it might work for 32 to 40 with an appropriate header, by tuning connector length to the RPM you want to run with your chosen prop and fuel.
I have used pipes extensively on high performance racing/speed planes, inboard/outboard model boats and full size carts/motorcycles but prefer the simplicty and ease of using a muffler for stunt and like a 4-2-4 type run.

Chris Wilson · « **Reply #5 on:** October 21, 2012, 10:30:31 PM »

Quote from: Reptoid on October 21, 2012, 09:55:15 PM

If you stick a random small engine pipe on the end of a long header you will in effect just have a non-power improving muffler.

Ah, that was plan B.

Shove it directly onto the exhaust stub with no header and see how it goes. Thanks.

Steve Helmick · « **Reply #6 on:** October 23, 2012, 10:28:45 PM »

Are these Mini Pipes manufactured D.U. someplace? They're for rear exhaust engines only, or are there side exhaust elbows available also?

Are you familiar with the "MACS Mufflers"? http://www.macspro.com/onepiece.asp The #6650 works very well on .40FP's and .40/.46LA's, but you have to prop them for a bit over 10k at launch and get the airspeed you want. No baffles, all one piece with the exhaust flange welded on.

Posting pictures is pretty easy. Click on "Additional Options" (below text field on left), then browse, choose your picture and post. It has to be 1,000 kb total or less, for all of the pictures in one post, whether one picture or 10 (or is it 20?). Note that this picture is really too large, and will require scrolling back & forth to see the left and right edges, a minor problem. It may also make the text extra wide and require scrolling to read, a major PITB.

Steve

Chris Wilson · « **Reply #7 on:** October 24, 2012, 12:42:18 AM »

Quote from: Steve Helmick on October 23, 2012, 10:28:45 PM

Are these Mini Pipes manufactured D.U. someplace? They're for rear exhaust engines only, or are there side exhaust elbows available also?

Are you familiar with the "MACS Mufflers"? http://www.macspro.com/onepiece.asp The #6650 works very well on .40FP's and .40/.46LA's, but you have to prop them for a bit over 10k at launch and get the airspeed you want. No baffles, all one piece with the exhaust flange welded on.

Posting pictures is pretty easy. Click on "Additional Options" (below text field on left), then browse, choose your picture and post. It has to be 1,000 kb total or less, for all of the pictures in one post, whether one picture or 10 (or is it 20?). Note that this picture is really too large, and will require scrolling back & forth to see the left and right edges, a minor problem. It may also make the text extra wide and require scrolling to read, a major PITB. Steve

Hi Steve,
are these pipes made in Australia? No idea mate, but its where I bought it from.

I am familiar with Macs pipes and I am also familiar with postal charges from the US to OZ.

Um, where exactly is 'below the text field on the left?'

Cheers.

Steve Helmick · « **Reply #8 on:** October 25, 2012, 05:45:39 PM »

Quote from: Chris Wilson on October 24, 2012, 12:42:18 AM

Um, where exactly is 'below the text field on the left?'

Cheers.

Uh, that would be below the area where you type in your experience/opinion/facts, and in the left margin. About 8 O'clock on an analog clock, if you remember those. Well, it will probably be different for you, being a different day and the time zones, etc.

But where it says "+ Additional Options...", well, just put your cursor there and push down on the left mousey button once (unless you're left handed, of course). The dropdown menu has some boxes to crick...crick on the "browse" button, and go find the picture you want to post, wherever it is on your computer. Read the instructions under that ("allowed file types, etc."). Try and help Sparky's balance book by keeping the photos down around 600-800 pixels wide and 100kb...easy peasy. If you don't have software to do that, IrfanView is freeware that works well and is very easy to figure out (I did!).

Steve

Chris Wilson · « **Reply #9 on:** October 25, 2012, 06:57:21 PM »

Quote from: Steve Helmick on October 25, 2012, 05:45:39 PM

Uh, that would be below the area where you type in your experience/opinion/facts, and in the left margin.

Got ya! Thanks.

Author Topic: Mini Pipe. (Read 2180 times)

Chris Wilson

Mini Pipe.

Steve Helmick

Re: Mini Pipe.

Reptoid

Re: Mini Pipe.

Chris Wilson

Re: Mini Pipe.

Reptoid

Re: Mini Pipe.

Chris Wilson

Re: Mini Pipe.

Steve Helmick

Re: Mini Pipe.

Chris Wilson

Re: Mini Pipe.

Steve Helmick

Re: Mini Pipe.

Chris Wilson

Re: Mini Pipe.