Im pretty sure I will buy the 80" Edge 540 ARF with the OS 1.60, I see it comes without a muffler. my question is where do I buy either a good muffler or pipe and header for this engine? also thinking about using a 18x6w prop will the prop be ok to use? according to OS they reccomend the following props? Aerobatic: 15x12-14, 16x10-14, 16.5x10-13 Sport: 17x10-13, 18x10-12

Get the Macs one piece muffler. It saves you 6oz. over the OS powerbox and gives the same or slightly better performance. Do not get a header and tuned pipe as they will kill your midrange.
[link=http://www.macspro.com/onepiece.asp]Macs One-Piece #7310[/link] This is the one you want. Get a better price at a hobby shop or eBay. For props I like the Xoar 18x6. The APC W's are heavy.

Also excellent resources at The profile brotherhood . com

The solution is to use the MACs header part 4311 and a sport pipe rather than a tuned pipe. The most popular sport pipe setup right now is using the budweiser beer can pipes. We have a local guy here that is making them for us and we had a ton of them for sale at Toledo. Email [email protected] or give him a call to order the header and bud pipe as a combo with the 80" Edge. We also have the OS 160 engines in stock and offer a good savings if you buy the arf and engine. 18-6W is the best prop for sure. Either the APC, pro Zinger, Zoar, or Vess are good choices.

As requested by some here are some pics of my bud pipe on the 80" Edge. We have a bunch of these in stock with the MACs Header. Must call to order those.

That looks awesome, I did order one when I ordered the edge, thanks for all your help

One thing I did not mention is that you need to add the pressure port on the header flange right by the engine exhaust. Just drill and tap a hole for a 6-32 pressure nipple.

I would guess the pressure fitting is shipped with the mufffler?

The MAC's muffler has the biggest pressure nipple I've seen.

Probably for commercial one piece mufflers, but not with the headers. If you get a MACs header and use a custom bud pipe or any other pipe, you'll have to drill, tap, and install the pressure fitting yourself.

Or poke a hole in the beer can with an awl and poke the line into the hole. It works.