VT-VZ Exhaust What's Responsible For Drone

[Mohit]

I have a supercat cat back on my SS no drone at all sometimes makes you wonder if it is a V8 until you get up it not loud really not to me it sounds just nice ,but in saying that my kids hear me leaving home in the morning for work 7.30 am they like how it sounds so all good here ..

Exactly how the Supercat used to sound like on my VYII SS, which is why I was surprised with the drone on my VYII Calais when another Supercat was fitted to it.
I'm sure once the quieter rear muffler is put on by the shop it should be all good again, like this:

[wally01]

Mine is louder than that now has 35 k on it still sounds good though ,and your SS with that cat back was the reason i bought one it was just what i was looking for ..

[wally01]

Some people seem to get quality of note mixed up with volume of noise. I like a good loud V8 like anyone, but would not trade loudness for a good quality deep note. How your car sounds outside compared to what you hear in the cabin is also a factor.

Alot of people that have heard mine have said it sounds very nice ,quiet at first get into it and it and it stands out ..

[Mohit]

So looks like I wasn't imagining the extra drone from when I last had the Supercat cat back on my previous LS1 car.
Spoke to the exhaust shop and he said there are 2 versions of the rear muffler, a quiet and a loud.
Most people ask for a loud system so they fit the loud rear muffler.
They are ordering the quiet rear muffler for me and will swap it over.
Let's hope it's as good as I remember from last time.

Problem solved.
The exhaust shop put on the quieter (much larger) rear muffler and the drone is now gone.
Part number for the quieter/larger rear Supercat muffler is SCMS 5001.

[VL Executive]

The key to the drone problem on VT - VZ exhaust systems is definantly in the rear muffler/s. I have a VY SS Ute, and went from a stock system to a Manta twin 2.5" with centre mufflers and rear hotdogs, and the drone is bad at highway speeds 100 km/h in 6th gear or around 1500 -200 rpm. Got the full mufflers from Manta and put those on in place of the hotdogs and drone problem gone. Only trade off is it took away abit of the nice deep note and loudness it had with hotdogs.

[QldKev]

The key to the drone problem on VT - VZ exhaust systems is definantly in the rear muffler/s. I have a VY SS Ute, and went from a stock system to a Manta twin 2.5" with centre mufflers and rear hotdogs, and the drone is bad at highway speeds 100 km/h in 6th gear or around 1500 -200 rpm. Got the full mufflers from Manta and put those on in place of the hotdogs and drone problem gone. Only trade off is it took away abit of the nice deep note and loudness it had with hotdogs.

Did you try hotdogs in the center and keep the rear resonators/mufflers?
Hotdogs up front for mufflers won't muffle the sound as much hence will allow a deeper / louder sound
A decent resonator at the back will then help get rid of the resonating frequencies that cause drone.

[macca_779]

Did you try hotdogs in the center and keep the rear resonators/mufflers?
Hotdogs up front for mufflers won't muffle the sound as much hence will allow a deeper / louder sound
A decent resonator at the back will then help get rid of the resonating frequencies that cause drone.

Bingo. My car is pretty loud with that config and doesn't drone

[white lie]

The closer you can get that back muffler to the end of the system, the less drone you're going to have. This is a no brainer and applies to all exhaust systems.

Otherwise the sound is just going to echo and resonate in the metal pipe all the way to the end. If you break the sound waves up right before they hit the end of the pipe then there's no chance of that happening.
So either keep/install a decent resonator at the back of the car or dump the system right behind the middle mufflers

[VL Executive]

Did you try hotdogs in the center and keep the rear resonators/mufflers?
Hotdogs up front for mufflers won't muffle the sound as much hence will allow a deeper / louder sound
A decent resonator at the back will then help get rid of the resonating frequencies that cause drone.

Bingo. My car is pretty loud with that config and doesn't drone

I was originally ment to get the Centre hotdogs and rear mufflers configuration. But Manta buggered up the order and ended up with Centre 'muffs and rear 'dogs. The reverse of what I wanted. So as a quick fix, I got the rear muffs / ressies from them. When I want quiet highway running, I change to the muffs and when I want the louder better sound around town short runs I put the hotdogs on. Takes about 10 mins to swap 'em over.

[kewgi]

I'm running a X-force cat back with a rear resonator on my wagon and I can hardly stand the drone. Originally it had a straight through rear section and it was terrible. I had hoped the resonator would have fixed it.

[Wonky]

Sounds like you need a bigger rear muffler kewgi to reduce/eliminate drone. However, it will probably also reduce how loud it is which you probably don't want.

[QldKev]

Change your diff ratio to a shorter ratio to free up the load on the engine, it helps reduce drone, and the extra off line performance is a win win.