Deeper Burble

[sti and]

Have the Blitz nur spec (cat back) exhaust on my Hawkeye impreza and was wondering if it was possible to get the car sounding a bit deeper? Would putting a de cat pipe or induction kit/high flow panel filter make a difference or just make it even louder rather than deeper?

[beefoss]

Increasing the bore size from 2 and a half to 3 inch really deepens the burble. Like you said it also increases the volume with a decatted pipe aswell. I've got a full cobra 3 inch decat and its very throaty!!! Also very droney on the motorway.

I don't know whether ported headers would make a difference but maybe someone else will be along sometime soon to let us all know.

[spect]

I believe the deepness of the Burble comes from the size of the back box. You do need to remove the resonator box from the centre section too. Best bet is to find someone who has the sound you want and buy the same kit as them.

[sti and]

Thanks for the info Beefoss & spect. Will be keeping my ears open Beefoss did you take the Down pipe cat out or the cat pipe between the down pipe and the centre section?

[beefoss]

Both are out, mine has the resonator in the centre section and a 4 and a 1/2 inch backbox. It gives out a lovely tone but I'd suggest maybe a sports cat in there somewhere as MOT's don't allow a full decat.

Whereabouts in the country are you as If its near then I'd happily let you have a listen.

[spect]

I have de-catted the downpipe and got rid of the resonator box and have the Ninja 2 back box. Not too noisy but you can hear it coming!

[sti and]

Beefoss I'm up in Scotland so not local. Good of you to offer though, thanks. See from another post your away off on tour, stay safe out there.

[spect]

Beefoss is now winging his way to Afghanistan!! So even further to travel.

[dannychapman]

i have 3inch straight through except a short backbox and ported headers. does sound different to other classics, more deeper but since i ported it got slightly louder in my opinion. il dig a video out and excuse my m8 sounding a dick lol, and this was a private test track on my garden.

My link

My link

Edited February 13, 2013 by dannychapman

[sti and]

Thanks for the link. Does sound rather deep Am I right in thinking that If I replace just the cat pipe I need to get the car remapped or is that only if you de-cat or sports cat the down pipe?

[dannychapman]

Thanks for the link. Does sound rather deep Am I right in thinking that If I replace just the cat pipe I need to get the car remapped or is that only if you de-cat or sports cat the down pipe?

my car ran fine without for months but made the map made a difference, someone cut the cat temp wires on mine but probally could bung it. mine is a classic so maybe different. i think if i remember if you decat watch your boost or adjust wastegate to were it usually boost. may cause it to creep. it did this when i ported the headers.

[spect]

I would personally not want to run it de-catted without a map as the whole flow through the exhaust is different and cause issues.