Creative but easy drone improvements?

[MrC1]

I've done some searching on the topic and have read about a few different ideas on how to get rid of aftermarket exhaust drones, but I'm wondering if anyone's tried any easy creative ways to help it. I dunno, maybe something like inserting deflectors in the tips or something?? Jsut a dumb idea that probly won't do anything.

I could always install some glasspacks where the original resonators/muffs were I guess. That shouldn't hurt flow, right? Maybe something like this: http://store.summitracing.com/partde...5&autoview=sku

BTW, I'm running the Magnaflow catback.

[Super T]

glasspacks sure as hell won't reduce drone. Drone is just a result of the exhaust note hitting the natural resonant frequency of the pipes, causing them to vibrate a whole lot more and make all sorts of racket. Resonators earned their name because they prevent resonance at the problem frequencies... they're tuned for the specific application. It's not like slapping a Flowmaster 40 on that will quiet the car down some no matter what the make/model... these are actual engineered pieces of metal. So easy/creative? You might get lucky... but a deflector in the tip will limit flow.

[topfuel67]

The SRT8s don't suffer from drone. The little hemi's with that mds suffer from drone when 4 of the 8 cylinders shut off on the highway and that makes some god awful sound (never been in one so I wouldn't know). The SRT8s don't have that (yet) so if you are complaining of drone in an SRT8 then you should've just left the stock exhaust alone. The stock exhaust flows nice and there is minimal hp gains in aftermarket exhaust. They're just louder.

My friend has the magnaflow on his srt8 and that is not drone. Its just a nice deep throaty rumble. The way an exhaust should sound. I have the corsa and don't like it. Its a bit louder than stock, but still quiet.

[MrC1]

My Magnaflow catback drones badly at 1500-1650 RPM. Otherwise they sound great.

I've read that a full exhaust upgrade (headers back) gains about 30 hp on these cars. The same article said a catback gains about 15-20. It was in one of the mags, and no it wasn't an advertisement!

I was thinking adding the 'packs might alter something in the resonance, but I guess I could be wrong.

[daveleck]

There's resonance/drone and then there's 'MDS noise'. Resonance/drone occurs in lower RPMS (1500-2000) and of course the MDS noise occurs whenever MDS engages. Obviously an SRT-8 is not having MDS noise issues...

[MikeEast]

Totally different animals too, resonance and mds-noise (<-- I like that description).

Resonance (to me) is when everything adds up just right to deafen you with rythmic throbbing pulsations of all the air molecules in your immediate vicinity, driven by the exhaust pressure doing it's own rhythmic dance inside the (now maybe not) cleverly engineered exhaust cavities underneath the car.

Kind of like driving down the road in a Magnum with just the drivers window open - at some speed everything will start to resonate and feels like it could take out an eardrum if it got just a little bit better. My 1981 Plymouth Reliant Station Wagon on No-Steroids was amazingly good at that part - it got painful for real at certain speeds.

MDS-Noise? You just took the flow volume of a V8 and all the pipeage designed to flow/muffle that configuration and are now pushing a big fat V4 through it. Pulses and flow don't add up right anymore and a great hollow booming sound can be heard when resonation sets in. Convieniently enough, right about 65-75 mph. Properly muffled/resonated it's just-not-there. Invisible. Start mucking about with things and you start hearing it. Zoomers turns MDS-noise into more a B-Flat with no real problem listening to it, because it only sounds a bit out of tune, not any louder.

The Dodge Boys did a pretty nice job of muffling these things really, I was very disappointed to start mine for the first time and hear it sound like a small toaster. Now however, I think of the Caddy commercial about my car turning me on when I turn it on.

Mike

[Chrispy]

The HF cats with catback sounds great but it is VERY deep at 1300-1500rpm and a little too loud for the wife and kids.

Here's what I did to quiet my setup down...

Installed stock Xpipe in front of mid muffler
Installed dynamat exteme (Just four 4x4 sheets)
One roll of dynapad in the trunk

Made a huge difference, it is much better and there is improved throttle response from the install of the Xpipe which is nice.

If I had my time back I would have bought two rolls of dynapad and not bothered with the dynamat extreme. (Dynapad made a nice difference and is a direct fit with no cutting required)

[dodgeboy]

The HF cats with catback sounds great but it is VERY deep at 1300-1500rpm and a little too loud for the wife and kids.

Here's what I did to quiet my setup down...

Installed stock Xpipe in front of mid muffler
Installed dynamat exteme (Just four 4x4 sheets)
One roll of dynapad in the trunk

Made a huge difference, it is much better and there is improved throttle response from the install of the Xpipe which is nice.

If I had my time back I would have bought two rolls of dynapad and not bothered with the dynamat extreme. (Dynapad made a nice difference and is a direct fit with no cutting required)

Where did you find your direct fit dynapad? I'm having trouble finding one that isn't universal, requiring cutting. I'd like to try some of your ideas on my car because the 1100-1500RPM drone is driving me crazy.

thanks,
Dave

[Chrispy]

I just used the roll and it fit

You take out the carpet/cover in the trunk and roll it out. Part of the excess goes down behind the back seats a couple of inches and you have a small lip that goes up the back of the trunk. Like I said if I had my time back I would have bought two rolls of the dynpad. If you decide you need to cut its no big deal. Just use an exacto knife and straight edge
(I'd cut the second one to fit the edges and use the remaining to double layer in the rear of the trunk)

Cheers

[BigIke]

What color is your c20?

[Chrispy]

I'm actually now considering putting the stock rear resos back on the car. The deep noise at 1300-1500rpm seems to be getting louder instead of quieter over time!

Little disapointed and might lose a little power but that noise has got to go...

So I'll have the following: HF magnaflow cats, stock Xpipe into 3 inch pipe into magnaflow mid muffler, to 3 inch pipe all the way to stock resonators in the back.

This will definitely kill the noise at that rpm range and still have a nice bump in sound over stock. I might do this change on Saturday and will post back with the results...

[dodgeboy]

I'm actually now considering putting the stock rear resos back on the car. The deep noise at 1300-1500rpm seems to be getting louder instead of quieter over time!

Little disapointed and might lose a little power but that noise has got to go...

So I'll have the following: HF magnaflow cats, stock Xpipe into 3 inch pipe into magnaflow mid muffler, to 3 inch pipe all the way to stock resonators in the back.

This will definitely kill the noise at that rpm range and still have a nice bump in sound over stock. I might do this change on Saturday and will post back with the results...

I feel your pain! Please let us know the results. I am also considering going back to stock (behind the HF cats).

Dave

[Chrispy]

Will do...It's too bad really, spent alot of money on the system and subsequently a lot on changes to it...

[stevesrt8]

just another note to this thread...

you guys on the fence about exhaust may wish to note that the stock pipes REALLY pick up over time/miles.

Now at 24000 I have a real Hemi roar at WOT, and a neat idle sound that is a deep toned treat.

Never had that new, and still very civilized inside. Loving it.

[Chrispy]

I noticed a change in tone at ~5K miles in mine as well. I went with the magnaflow for the power gains moreso than sound (cats and catback consistently dyno 20-25RWHP higher than stock)

The exhaust is perfect except for that super deep note from 1300-1500rpm...