What Is Drone

dave-m · #1 Tue, December 1st, 2009, 10:17 AM

sorry to jump in on someone else's thread, but I keep reading about "drone"

what exactly is drone?

***88Racing*** · #2 Tue, December 1st, 2009, 11:51 AM

Drone is a noise that is created by the aftermarket cold air intake due to its construction and design and the way the air flows in it. The drone noise is from air resonating in the intake tube as it flows or is pulled in from the vacuum the motor creates. At some rpm intervals and to some people the drone is a very irritating noise=constant humming. This drone can be a real pain especially if you are on a long trip, trust me it gets real annoying.
I like others thought it was cool at first but after 6 months and some DTC codes, I removed mine and went back to the stock intake.
For the most part the noise occurs in the plastic style ones with the tappered tube design. It does occur in the metal tube ones also but not as often as the plastic ones.

***88Racing*** · #3 Tue, December 1st, 2009, 11:56 AM

I'll add this:
The drone noise can be tuned out by Bill but there are a lot of factors on weather or not this can happen.

dave-m · #4 Tue, December 1st, 2009, 02:06 PM

so dyi intake mod doesn't exhibit any of this, because of the stock design?

I'm still trying to figure out if there are any noticeable gains for the effort, even if the effort is quite minimal.

***88Racing*** · #5 Tue, December 1st, 2009, 02:46 PM

The DIY intake mod allows for more air at higher rpms. As long as you don't modify the OEM tube and take off the silencers there should be no droning noise some have done this and reported some noise when silencers were removed.
For $8-$15 the cost and effort is minimal compared to an aftermarket CAI and the gains you would get with that.

***Jackpine*** · #6 Tue, December 1st, 2009, 10:55 PM

I'll add to Lars' reply -

I did the mod, I think I've gotten improved performance (I'm sure it's helped my fuel economy, maybe by at least 0.5mpg), and there's NO drone. I didn't cut off the resonators.

As Lars mentioned, it cost me less than $10.

- Jack

***Jackpine*** · #7 Tue, December 1st, 2009, 11:53 AM

Dave, as you see, I've moved your post to the Gryphon section and out of "Support". It's no biggie, but we try to keep the support threads specific to one problem and on topic.

"Drone" is an unpleasant sound that seems to be related to installing some aftermarket intakes on the engine. It's probably a resonant frequency that is hit at certain RPMs which is triggered by turbulence in the airstream. If you look at an OEM intake, you'll see those funny looking rectangular shapes along the sides of the intake, which are called "Helmholtz resonators". They were put there to dampen out the "drone" frequency by creating opposing pressure waves whenever drone starts to happen.

Bill can adjust a tune to get rid of an intake drone usually. (But, I can't help but think this may actually be a sub-optimal solution - this is my opinion only. I feel the aftermarket intake should have been designed so that it doesn't induce drone in the first place.)

Edit: I see Lars and I were posting at the same time. Glad I got the explanation right!

- Jack