New 3'' Manta exhaust,does it quieten down after carboning up

[VFSSVfan]

Hi,just fitted a new 3 inch system,hurricane header & complete manta 3'' stainless steel system including hiflo cats to my vf ss series2 LS3 manual that has lsa supercharger & mild cam..

Like the deep note but it's a bit loud even though it's the quietest version available of the manta exhaust.
Will it quieten down much as it carbons up or should I fit the standard bimodal flaps to the manta mufflers?
Thanks in advance for your advice.

 

[lmoengnr]

Fit your bi-modal valves to the current mufflers.

 

[stooge]

I doubt it will quieten down much over time.
with the bimodal flaps you need to workout whether your mufflers are like this design

you see the valve is on the "straight through" pipe so when it is open you are essentially deleting the muffler and when it is closed the muffler will run the gasses through the baffles and quieten it down.
if your muffler is already running everything through the baffles then adding the bimodal valves wont change too much apart from turning the dual outlet into a single so it might drop the noise a bit but not as much as you need.

if you have the muffler like the picture with a straight through type pipe then adding the bimodal valve to that outlet will quieten it down a fair bit.

 

[Unicorn]

Its the cats helping make it louder.
If they are 100 cell cats you may as well have no cats,they are there for looks mostly,maximum flow and noise to go with it.
The noise difference between the same cat back system with stock cats and 100 cell cats is huge.

Edited

 

[BlackVXGTS]

...Will it quieten down much as it carbons up or should I fit the standard bimodal flaps to the manta mufflers?.........

They won't get quieter, if anything they will get louder.

 

[PeteSS]

Mines similar set up, LS3 with Magnuson supercharger and a cam.

It had a full 3 inch Pacemaker system ( 1 7/8 inch headers, 100 cel cats). hideously loud.

Put a 2.5 inch Hurricane cat back with quite restrictive mufflers. Noticeably quieter when driving, though still too loud at idle, which i'm guessing due to the cam.

Like Stooge said you could be wasting your time putting the bimodal flaps on your mufflers. Try blocking off one of the outlets and see if it makes a difference

 

[vr304]

Would expect it to get louder if anything once it carbons up mate

 

[gtrboyy]

Yep will get louder after a few heat cycles.

Bloke at work has whipple blown 7 litre vf clubbie...with bi-modals closed you'd never guess it had 700rwhp

 

[Strattos]

If it's any help, I've just had a new exhaust system installed and as others have said, will get louder if anything. Now have 1000ks on it.

No blower or cam on mine, but with engine-back 3" with 1 7/8 headers (all DPE) bimodals made a decent enough difference.

Not sure if its the same as the pictured muffler design above, but for me makes enough of a difference to not worry the neighbours, which is really the only reason I had them fitted - that and being able to relax at stop lights with a copper behind you.

Big enough difference at idle with this setup to make it worthwhile.

 

[abuch47]

Does anyone else notice any rattle from an open aftermarket system with bimodal closed?