Written by Rob Turnbull Monday, 30 November 2009 22:40
This article introduces the GP exhaust Nitropower 91 muffler. There is also a link to a flight video showing this muffler in action on my Avant Aurora Ultimate 90.
Introduction to the Nitropower 91 muffler.
Having used this muffler on my Aurora for months, and lots of flights, I'm happy to say that it has never once caused me any problems and delivers outstanding power on the OS 91 HZ that I'm using in that helicopter.
The build quality is top notch, as is the finish of the muffler.
The power delivered by this muffler is excellent. The tuning band is fairly wide and is quite forgiving of richer running engines. To get the power you generally need to tune your engine leaner although the GP Exhaust is quite forgiving here and as you can see in the video, there is a good smoke trail using Optifuel 30%, so I'm running a fairly rich setup while still pulling bags of power!
Compared to the Muscle Pipe 5 that I replaced with this muffler, the GP Exhaust is a big improvement in terms of better tuning and more power delivered.
I'm happy to recommend this brand of mufflers (now that I've used a variety of their 50 and 90 sized mufflers personally).
The flight video of the Nitropower 91 muffler in action on my Avant Aurora Ultimate 90 is in the Video > Flight section of this site.
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