Exhaust question concerning drone.

[Raf The Weasel]

Hey guys, just had a question concerning the srt8 and hemi models. I've been thinking about getting an exhaust for my srt8. I know people have had drone problems on their hemi's because of the MDS. Will the Srt8 get any type of drone since it's just a straight up 6.1 liter with no MDS?

[niner49]

Can someone pease tell me what the hell is a "drone" or "MDS"? (Sorry for the stupid question) But I see those words all the time and I have no Idea what they are. I also have a SRT8 and I would like to install an exhaust, and would like to learn more before I do anything.

[bruno]

Originally Posted by niner49

Can someone pease tell me what the hell is a "drone" or "MDS"? (Sorry for the stupid question) But I see those words all the time and I have no Idea what they are. I also have a SRT8 and I would like to install an exhaust, and would like to learn more before I do anything.

Now you know, there is no such thing as a stupid question on this forum! The V-8 HEMI 5.7 has a multiple displacement system.MDS shuts down four of the 8 cylinders when the engine is operating under a low load, which occurs in stop-and-go city traffic and when the car is cruising at steady highway speeds. It's only when you stomp on it that you're firing on all eight cylinders. The transition from four to eight cylinders and back again is seamless and undetectable. DaimlerChrysler claims it will reduce fuel consumption by at least 20%. The 6.1 SRT-8 does not have MDS so this drone does not seem to be an issue with aftermarket exhaust systems.

To me, a drone is a constant noise and vibration you feel while inside the car that is annoying to the point of driving me crazy. The constant sound can interfere with conversation and the internal body vibration is like some type of torture.

bruno

[niner49]

Thanks for explanation! I always thought the SRT8 had the MDS. Oh well I guess its 20% more fuel

Originally Posted by bruno

Now you know, there is no such thing as a stupid question on this forum! The V-8 HEMI 5.7 has a multiple displacement system.MDS shuts down four of the 8 cylinders when the engine is operating under a low load, which occurs in stop-and-go city traffic and when the car is cruising at steady highway speeds. It's only when you stomp on it that you're firing on all eight cylinders. The transition from four to eight cylinders and back again is seamless and undetectable. DaimlerChrysler claims it will reduce fuel consumption by at least 20%. The 6.1 SRT-8 does not have MDS so this drone does not seem to be an issue with aftermarket exhaust systems.

To me, a drone is a constant noise and vibration you feel while inside the car that is annoying to the point of driving me crazy. The constant sound can interfere with conversation and the internal body vibration is like some type of torture.

bruno

[Sleeper300]

Layman or Un-car-guy

I would explain drone as a deep bass pitch that resonates within the cabin of the car and interrupts conversations seriously and almost makes the car undrivable with a hangover. Liveable, YES, yet while driving in D (drive) the lower rpm's are worse and the noise level compared to stock is ten times louder inside, Corsa is the only exhaust Cat-back which is now on my car that doesn't exhibit any Drone effect at all inside the cabin, now at cruise the car is very mellow, almost stock like, yet when opened up or slight throttle input (moderate acceleration) the deep aggressive note is very nice and has a very good bark at full boogie.
If you don't mind the sports car sound inside and out, any exhaust will do, for luxury car interior quietness that the stock exhaust allow's theres only one option.

Just my 2 cents.

[niner49]

So your saying that the Corsa exhaust does not sound loud inside the car? Sound similar to stock? What about outside? Is it loud? If I also put a set of headers on would it make a big difference? I don't want loud/drone...I just want a nice rumble more then stock and proformance of course.

Originally Posted by Sleeper300

Layman or Un-car-guy

I would explain drone as a deep bass pitch that resonates within the cabin of the car and interrupts conversations seriously and almost makes the car undrivable with a hangover. Liveable, YES, yet while driving in D (drive) the lower rpm's are worse and the noise level compared to stock is ten times louder inside, Corsa is the only exhaust Cat-back which is now on my car that doesn't exhibit any Drone effect at all inside the cabin, now at cruise the car is very mellow, almost stock like, yet when opened up or slight throttle input (moderate acceleration) the deep aggressive note is very nice and has a very good bark at full boogie.
If you don't mind the sports car sound inside and out, any exhaust will do, for luxury car interior quietness that the stock exhaust allow's theres only one option.

Just my 2 cents.

[onedug]

I think they were trying to say that if you have a SRT there's no MDS(which kicks down the cyclinders) so you don't have to worry about drone as in the 5.7 engine

[jconnolly1119]

Any cat-back system is going to have a certain tone, but some will have a frequency(or pitch) that will have a resonance and this is what you'll hear in the car usually at lower RPM's. I have the Magnaflows and they do have a drone at 1500rpm's, which if you tool around in drive alot you will experience regularly. Headers shouldn't really make the drone or resonance louder, but they will give the system a different sound----but not neccessarily a louder one.

The Corsa system seems most like the stock rig in terms of volume and drone issues.....basically it's the quietest. Then the Borla and MF which have some drone but aren't quite as loud as the Zoomers (although these seem to have less drone).

Alot of folks will put on headers, but retain the rest of the stock exhaust to stay quiet and more stealth. Other folks (like yours truly) don't mind folks hearing me coming..........start up is always a headturner and WOT is nothing but grins.............

[jconnolly1119]

Originally Posted by jconnolly1119

Any cat-back system is going to have a certain tone, but some will have a frequency(or pitch) that will have a resonance and this is what you'll hear in the car usually at lower RPM's. I have the Magnaflows and they do have a drone at 1500rpm's, which if you tool around in drive alot you will experience regularly. Headers shouldn't really make the drone or resonance louder, but they will give the system a different sound----but not neccessarily a louder one.

The Corsa system seems most like the stock rig in terms of volume and drone issues.....basically it's the quietest. Then the Borla and MF which have some drone but aren't quite as loud as the Zoomers (although these seem to have less drone).

Alot of folks will put on headers, but retain the rest of the stock exhaust to stay quiet and more stealth. Other folks (like yours truly) don't mind folks hearing me coming..........start up is always a headturner and WOT is nothing but grins.............

[kings11]

Originally Posted by onedug

I think they were trying to say that if you have a SRT there's no MDS(which kicks down the cyclinders) so you don't have to worry about drone as in the 5.7 engine

Uh, sort of. All exhausts have some RPM frequency that will produce "drone" at some level of annoyance! Magnaflow's happen to produce that drone at a very common RPM (like 2,500 or 3K RPM) at 60 mph while on the freeway when the MDS kicks in!

Well engineered exhaust systems bend the pipes, create baffles, open up the diameter of the pipes, etc. where the drone happens at less common RPM's (outside of normal driving ranges I suppose).

So that is the rest of the story.

On a foot-note, drone is a very personal and subjective thing. In my case, the drone from the Magnaflow is most noticeable at 40-70 mph. However, the drone I hear (and it is obvious when the MDS kicks in), isn't annoying to me. I interpret it as just a deeper growl in the engine exhaust.

Cheers,

Scott