Exhaust size velocity vs volume

[Vortex-98]

I'm trying to get the exhaust sounding a bit better ,I'm getting sum new headers but when it comes to size it gets a balancing act ,the smaller diameter exhaust pipes better for velocity an moving the air faster than a bigger diameter which is more for volume r but as it has 2 pipes on the inlet the noise they make isnt pulsing in harmony an they cancel the flow of the other making for a stock idle..

[T3rminator]

Do you have a big merge pipe in your current system? If you do, remove it or make the merge section much smaller.

I've never heard a bad sounding AU V8.

[NCII40]

Manta Cat back
High Flow Cats recommended
H pipe already on the kit

https://www.youtube.com/watch?v=RipCZpvv_ag

https://www.ebay.com.au/itm/MANTA-PE...-/172378990840

[Vortex-98]

Tickford 4 into1 extractor an cats into 3 or 3.5 mandrel into centre muffler an then 3in resonator...I'm thinking of fitting a twin system from Cats back,after I get my extractors fitted...can extractors stock xr8 or paceys be fitted an removed easily or do I have to take it to a shop to get it up on a hoist

[Bossxr8]

Originally Posted by Vortex-98

Tickford 4 into1 extractor an cats into 3 or 3.5 mandrel into centre muffler an then 3in resonator...I'm thinking of fitting a twin system from Cats back,after I get my extractors fitted...can extractors stock xr8 or paceys be fitted an removed easily or do I have to take it to a shop to get it up on a hoist

A single 3 inch is actually smaller than the factory twin 2 inch.

Go twin 2.25.

[Sox]

Originally Posted by Bossxr8

A single 3 inch is actually smaller than the factory twin 2 inch.

Go twin 2.25.

No it isn't.
A 3" single has about 12% more area than twin 2".

[Bossxr8]

Originally Posted by Sox

No it isn't.
A 3" single has about 12% more area than twin 2".

But not as much as twin 2.25, which is what he should use.

[Sox]

Originally Posted by Bossxr8

But not as much as twin 2.25, which is what he should use.

Depends what he's chasing.
As I understand his engine is very mild, so a single 3" is probably better than dual 2.25".