Sorry I missed responding to this earlier... I did cut my header and found I still got about 100-200 more RPM over the stock pipe. This was cooler weather of course and a new engine.
In a much earlier post I posted all the tach/dB measurements I got when using several mufflers (5 or 6) including stock cut and uncut. The Hyde pipe with the cut off header gave me 100-200 more RPM... though not the 7000 my buddy NEO is gettting in current weather.
I will check again my rpm's and noise levels with the pipe once I get the opportunity.
ORIGINAL: racekannon
I got this e-mail after I sent this:
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[email protected] wrote:
> I followed his lead with my hyde pipe and am worring. Please elaborate. thanks
[email protected]
The Hyde pipe is actually a tuned silencer and is affected by header length. The shortened header causes the return exhaust pulse to hit the exhaust port at the wrong time, essentially creating an excessive backpressure and robbing horsepower. The resulting effect causes a 500 RPM loss over stock, instead of the desired 100-200 rpm increase. We will probably have to use the flexible question mark header and actually mount the big part of the cannister over the landing gear block. I am not even going to bother right now, as I am happy with the weight loss from going back to stock, and I want to get the engine broken in first.
I would have loved to have known this earlier I cann't find it in the thread. I just wasted alot of time. I am sick and haven't wanted to touch the plane since finding out. My options are tear up plane while removing pipe while having to ruin pipe to remove. I mounted my engine and made and installed everything just this week.