Stock exhaust drone at 2000 RPM?

[thorny]

I have run Akra Evo for about 2 years, recently I sold the Akra and installed my original OEM X-pipe and bought from 3rd party OEM slip-on. So the exhaust is 100% stock. The engine is 100% stock too.

The car drones at 2000 RPM, especially when cold. It is a hollow sound if you keep the needle at 2K, when engine has not warmed up. It gets better when the engine warms up, but still cruzing at 2000 rpm in 7th gear for example it drones. I am totally lost why on earth I would have drone now..

Maybe somehting is not tight enough, but I have done install on x-pipe and slip-on at least 4 times now..

Did anyone else experience something like this?

Thank you

[BrewRifle]

Are you certain that the exhaust wasn't tampered with?

[Blue92]

2000 rpm is the resonant frequency on many exhaust systems. At this rpm you are getting exhaust pulses from each cylinder at 2.05 times per second from our V-8. Move just a little bit either way and, it's gone... I actually enjoy cruising at this speed (all stock, OEM exhaust)

[thorny]

Thank you for your responses. I found the problem!

I installed two black rubber hangers on the sides of the slipon backwards, they are interchangable between left and right, but you can attach them two different way anf only one way is correct. The bolt is not in the middle, so if you attach it one way, the slipon will be hung maybe 0.5 inch closer to the back of the car or further from the xpipe than the other way.

You can kinda tell if you did it wrong, becase you may have hard time getting a good fit between slipon and xpipe. Those clamps dont have enough power to squeeze pipes to ensure tight fit.

I turned those black rubber hangers, and eliminated a small gap between xpipe and slipon - no drone!!

Wonder how many people who complain about drone blamed it on slipon when really what they had is incorrect install like I did..

[thorny]

Originally Posted by BrewRifle

Are you certain that the exhaust wasn't tampered with?

No, it s all good. It was my fault. See above

[thorny]

Originally Posted by Blue92

2000 rpm is the resonant frequency on many exhaust systems. At this rpm you are getting exhaust pulses from each cylinder at 2.05 times per second from our V-8. Move just a little bit either way and, it's gone... I actually enjoy cruising at this speed (all stock, OEM exhaust)

Yes, i like that too, but i found the problem.

[Hujan]

Originally Posted by thorny

Thank you for your responses. I found the problem!

I installed two black rubber hangers on the sides of the slipon backwards, they are interchangable between left and right, but you can attach them two different way anf only one way is correct. The bolt is not in the middle, so if you attach it one way, the slipon will be hung maybe 0.5 inch closer to the back of the car or further from the xpipe than the other way.

You can kinda tell if you did it wrong, becase you may have hard time getting a good fit between slipon and xpipe. Those clamps dont have enough power to squeeze pipes to ensure tight fit.

I turned those black rubber hangers, and eliminated a small gap between xpipe and slipon - no drone!!

Wonder how many people who complain about drone blamed it on slipon when really what they had is incorrect install like I did..

You talking about these:

[thorny]

Originally Posted by Hujan

You talking about these:

Yes sir. Note how the hole is closer to one end, it is not centered. Blue arrow shows the right orientation