[NSRCA-discussion] 2C Pipe vs Muffler

[Chris Moon]

Jeff I ran a muffler in 2004 on my OS when I was starting back and just 
wanted a simple setup.  I ran the Bolly MF590 and it was a very nice and 
simple setup.  Last year I went to a pipe -Bolly EQ140R and copied the 
setup length etc. that Dave Lockhart used to run when he ran the OS.  I 
don't have numbers to compare but the difference is in the air when the 
motor unloads.  The pipe would run the APC 15 3/4 -11 or 10 (Lockhart) 3 
blade no problem but the muffler didn't have the muscle to pull it in 
the summer heat.  I would bet though they probably tached about the same 
on the ground.  People are running the pipe a little longer than max 
perf to keep the needle setting from getting too critical.  Ideally you 
would change pipe setting for temp - humidity etc but who wants to do 
that?  We just run a little extra length to have an "all weather" 
setup.  You still will have lots of power, just not "peak".

Chris

jeffghughes at comcast.net wrote:

> I was going through the data on Ed Hartley's 2 stroke page and noted 
> that there is virtually no difference between a piped OS1.40 and a 
> muffled OS1.40 for the prop sizes being used.  I assume that is 
> because to get a nice linear throttle curve on a pipe, the pipe is 
> deliberately set too long for peak horsepower. My question is why run 
> a tuned pipe at all if you are going to set it too long for peak 
> power?. Has anyone run back to back tests with same engine and plane 
> with a pipe vs a muffler to see if there is truly a difference in 
> power or feel?
>  
>
> ------------------------------------------------------------------------
>
> Subject:
> Re: [NSRCA-discussion] Fuel Regulation in 2C Engines
> From:
> "Tim" <twortkoetter at yahoo.com>
> Date:
> Mon, 6 Mar 2006 22:24:58 +0000
> To:
> "'NSRCA Mailing List'" <nsrca-discussion at lists.nsrca.org>
>
> To:
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