What makes an exhaust note sound deeper?

[TrophyJem]

Since swapping my Pinto engine for a Duratec the other year, I really miss the deep rumble that the Pinto used to give at tick over and low revs.

 

The Duratec just sounds, well tinny. Its all good on full blat (in fact its a bit of a mental sound), but its very disjointing low down.

 

So it got me wondering what actually makes an exhaust note sound deeper? 

[Andrew]

It's all about gender.. a Pinto's a manly beast, and Duratecs are a bit girlie. ... so I was told.

 

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[CraigHew]

The exhaust design and componenets can play a huge part in the sound

[Olliebeak]

It happens when you awake the Pintosaurus from his slumber. 

[TAFKARM]

Jem, I've got a 2.5 inch diameter exhaust  manifold (4 into 1) and silencer for sale soon that should sound quite meaty if youre interested...

[Dave Eastwood (Gadgetman) - Club Chairman]

Equally cam profiles and cylinder head design play a part; four valve per cylinder engines with lots of valve overlap, always seem to have quite a distinctive sound under load, at speed.

[TrophyJem]

Jem, I've got a 2.5 inch diameter exhaust  manifold (4 into 1) and silencer for sale soon that should sound quite meaty if youre interested...

 

Thanks for the offer, but I already have a 4 into 2 into 1 manifold of a decent size and the silencer is my old pinto one (maybe the silencer is a bit small).

The power output is great from the duratec. 200bhp on the rollers, so that's all good. 

It's just the sound I miss. I've even thought about putting it back in and converting it to efi, but that would just be bonkers.

The duratec is so much more drivable, quicker and dare I say more economical.

[Barry Ashcroft]

Simple, Cubic inches ;-)

[Greenstreak-Andy D]

Simples....

[Geoffrey Carter (Buttercup)]

I found that so incredibly funny. 

 

cannot stop laughing for some reason.        

[DE04*]

LOL brilliant.

[TableLeg]

I found that so incredibly funny.

cannot stop laughing for some reason.

Me too, I've got tears in my eyes from the drive by ending....

[stephenh]

Excellent!

[BenD]

lol the ending is the best

[tisme]

Haven't laughed so much in ages :d

 

When he drove off though, it sounded just like Rosebergs Mercedes

 

As for the OP question though - Dave is right - on a modern 16v engine a lot will depend on cam/valve overlap, unburnt fuel etc - does the Duratec system have a CAT - if so I'd try it without (or even the silencer) to see if there's any inherent "growl" in there. Changing to larger diameter pipes and or silencer may not alter things that much?