Well as much as I enjoy the sound of nitro engines...

It is down right F!@#!% annoying running a motor at wot for long period of time to run thru 1/2 gallon of fuel!

Is their a simple way to baffle the engine exhaust without causing any type of issue with back pressure.

Pics of any suggestion or device would be great.

Place a rubber tube on the stinger of the exhaust, in most rc shops you can find these tubes as an extension for the stinger.

run a helicopter pipe

I use a Plastic Coke bottle (preferably the big one), make a small hole at the middle of it so the stinger can be inserted into the bottle. Just open the bottle cap so the fumes can get out.

i use a 5ft piece of automotive rubber hose from my stinger out the door of my shop into a bucket(to catch the oil),no noise,no crying eyes,no smoke

WEAR EAR PLUGS!!!!!!!!!!!

hahahahha good one

ear plugs r the best method. rubber hoses were not meant to be attached to stingers. it creates way too much backpressure for these engines to handle.

if youre looking to hydraulically lock your new $500- $600 engine go for the rubber hose instead of ear plugs......

if you're running it in on the car slap on an INS box along with ear plugs

It really doesnt help that much, and at 1/2 throttle and WOT it starts to deform

never had an issue using a automotive heater hose,im 45 and been doing it this way since 1986 even on my heli's and planes.
if you are hydrolocking then you are setting/breaking in your engines incorrectly.

I just broke in my OS .12 on my stand with the stinger going into a one foot square cardboard box. It still made a bit of noise but not nearly as much as nothing. If you were to stick some fiberglass insulation in the box it will quiet it even more.