BK....I read those Links....
So.....Basically, if you cannot Accurately measure the RPM of your engine (after it has been tuned to its Peak capacity) at maximum speed, then it does no good to run a Header (tuned pipe) or a Stinger (exhaust chamber).
Unless, of course, it was designed Specifically for YOUR engine, (OS tuned exhaust on an OS engine). But you would STILL need a DYNO to determine the RPM of your engine at Top Speed, so that you could Tune in the Correct Frequency and hit the Sweet Spot. ( I dont Have a Dyno laying around....)
Specific top speed and RPM will be determined by type of Fuel (20%, 30%), Average ambient temperature and Humidity (Summer, Winter) and your tuning SKILL.
The Variables are virtually Endless. So, is it PRACTICALLY useless to install a Tuned Exhaust?
I dont think so, and here is Why......
I think Most of these engines come with an exhaust system that is SO Inefficient and Restrictive that almost ANY exhaust would be an improvement over the Cheap,Leaky,Plastic pipe that comes on Most RTR's.
I think that by increasing the flow of the AIR/FUEL mixture through an engine, you will increase the Horsepower in some degree, even without hitting that Magical Tuned Sweetspot......
I think that it is at least somewhat likely that you WILL hit that Magical Tuned Sweet Spot SOMEWHERE between the Startline and the End of the Street.
If you hit the Sweetspot at ANY point between the Start and the Finish, you will reap SOME Bonus of Dramatically increased horsepower and Lower Elapsed Times....
Besides.....They SOUND Cool!