ASP 46 with three different mufflers
 

I do testing for my own benefit & enjoyment & am happy to share my observations with everyone whose interested.

ASP 46 swinging an APC 10 x 6 with spinner nut. Fuel being 10% castor, 10% Klotz 200, 10% nitro & balance methanol. Ran the engine with 3 different mufflers to see the performance difference in changing only aspect of the engine setup - the muffler.

I used the following:

OS 873 muffler - 14,250 rpm

JENSD47 muffler - (obtained from Just Engines in the UK - this muffler bears has a passing resemblance to the Jett Stream muffler) 14,580 rpm

Tower Hobbies Aquacraft muffler - 15,090 rpm

The above tests were performed on a test stand. I later bolted the ASP 46 & Tower Muffler into my sports model & the performance improvement in the air over the standard OS873 muffler was very evident. "Bolt on" horsepower !

I did not have time to assess the JENSD47 in the air however bench testing suggests it should be a marginal improvement over the OS873 muffler, but a fair way short of the Tower muffler [8D]

RE: ASP 46 with three different mufflers
 

This is good data.

I would like to point out that the 10 X 6 prop allowed the engine to most effectively display the exhaust improvements

RE: ASP 46 with three different mufflers
 

Nice work Bone - thanks for the data.

As you said, the JENSD47 sure looks like a Jett/UT muffler type but I wonder if it's just hollow on the inside rather than having an internal tube from the header to the "bell" at the end like the real deals.

Those Tower/GMS/Aquacraft mufflers have got to be the best non tuned muffler option available for a .46 sized engine. Our club swears by them!

RE: ASP 46 with three different mufflers
 

Yes Harry, internally the JENSD47 is simply a hollow tube - nothing like what you have described as the internals of the JETT/UT muffler) - no baffles either. It also has a slightly smaller diameter than Tower muffler. It's very well made with thick solid castings, probably too solid as the completed muffler weighs 150 grams or approx 5.25 oz.

Will pull it apart this weekend & post some pics.

The lads at the field were impressed by the extra power obtainable from the Tower muffler - I can see a bulk order being lodged from Australia very soon [8D]