OS-50 hyper + Jason Kraus pipe WORSE than stock muffler????

[blue_collar2]

Kyosho calliber 5, 30% nitro, OS#8 plug

I've been getting disappointing performance with my new (and expensive) Jason Kraus pipe, so I decided to test it against the stock Kyosho muffler that came with the kit. I put the heli on a run-up stand, went to full throttle, and adjusted the mix for max rpms (read off a Futaba GV-1). Nothing else changed between tests of the two exhaust systems. Results follow:

Stock muffler: max rpm=1690 at 7/8 turn out on mix
Jason Kraus pipe: max rpm=1480 at 1 1/8 turns out on mix

I'm assuming I'm doing something wrong since a $125 pipe should outperform a free muffler...right?

Any thoughts would be most welcome!

[DavidH]

I put the heli on a run-up stand, went to full throttle, and adjusted the mix for max rpms (read off a Futaba GV-1)/

Should have took a video. We will need it for the Darwin award.

1/4 turn difference in mixture makes a difference.

David

[DebianDog]

A STAND???

You need a load on the motor. Once you get that thing TUNED IN THE AIR I think you will be more than pleased with it.

[BarracudaHockey]

:lolol :lolol @ harkey

Though he's completely correct.

[Maxists The Baddist]

Don't some stores sell those wiffle ball things that you can attach to the rotor head to do some sort of testing on the ground? I remember seeing them somewhere. I wouldn't do anything like that but what would you buy those for?

[BarracudaHockey]

Head loaders, they went out of style with parachute pants and mirrored sunglasses.

[Maxists The Baddist]

Were they to test the heli, make sure nothing falls off?

[cdrking]

I've been getting disappointing performance with my new (and expensive) Jason Kraus pipe, so I decided to test it against the stock Kyosho muffler that came with the kit. I put the heli on a run-up stand, went to full throttle, and adjusted the mix for max rpms (read off a Futaba GV-1). Nothing else changed between tests of the two exhaust systems. Results follow:

Stock muffler: max rpm=1690 at 7/8 turn out on mix
Jason Kraus pipe: max rpm=1480 at 1 1/8 turns out on mix

Ah, very scientific method. :roll: NOT!

My JK Hatori and Hyper 50 rock!

Dump the test stand.

Jeff

[flyinfool]

At the RPMs that you are running, the engine is not getting anywhere near its power band.

There must be something not right with your setup.

Also as the performance potential of a pipe goes up, the tighter the rpm bad where it will be effective.

Having the needle open farther with the JK pipe is normal and to be expected. The JK pipe has a lot less back pressure so there is less muffler pressure in the tank which means less fuel pressure at the needle valve, so the needle will have to be open farther to get the same flow.

The test stand is not a valid test because it does not reproduce the same loading as when flying. because the heli is not moving the effective pitch is a lot higher that what happens in the real world.

The JK pipe is night and day better than a stock muffler.

[bgjames111]

:lolol darwin award!