Another exhaust question

[Johnkathy81]

Needing advice if anyone can help. Have 2013 St D40. Had straight pipe and muffler removed previously and helped also could hear turbo spool etc.. Recently fitted "3" turbo back exhaust (no cat) and one rear muffler bolt on system. Car more quiet than before and can hear turbo less. Had bought a straight pipe to eliminate muffler and try, although too loud and sounded like a very muffled sound although could hear turbo heaps.

My question is and I'm thinking if If I replaced the dump pipe (with cat) and straight pipe would that help as to tone down that muffled sound? Any advice appreciated

Thanks.

 

[abouttogobush]

the dump pipe is the main restriction from the factory the cat wont make a pinch of difference to the noise from the arse end, no muffler will always give a louder whistle but not sure exactly what you are trying to do matey

 

[Johnkathy81]

the dump pipe is the main restriction from the factory the cat wont make a pinch of difference to the noise from the arse end, no muffler will always give a louder whistle but not sure exactly what you are trying to do matey

Thanks bud, that's exactly what I wanted to know I was just trying figure why the big flutter noise now when I use straight pipe but is obviously just the larger diameter. Thought maybe the cat not being there would have had something to do with it.

 

[abouttogobush]

yep spot on!

 

[mike1303]

Do you want it louder or quieter?

 

[Johnkathy81]

Do you want it louder or quieter?

Didn't want it too loud or annoying was just that with stock exhaust and straight pipe had bit of nicer tone to it (more whistle), can hear it now although differently and more quiet. Was more curious what the flutter was with the "3" when I had the straight pipe in but obviously being larger diameter, thought had something to do with cat. Didn't mind it touch louder but I'm guessing when the muffler wears in a little might sound better.

 

[mike1303]

ah huh,

people with the standard exhaust with a straight pipe get the whistle.
When you swap to a 3" ive never heard a D40 whistle.
When you remove the muffler from a 3" system Turbo back you get a ncie note. But still no whistle.

from what i find evey time i drive anyway

 

[Johnkathy81]

Yeah your pretty spot on, that's what I have found I have a slight but different type of whistle with muffler on, although with straight pipe I do get a fair bit of a whistle out of it although very fluttering noise and annoying, hence why I thought the cat had something to with regarding flow rate or something but sounds like I was wrong better just stick to building houses lol

 

[Johnkathy81]

Ok so I ended up replacing dump pipe with a high flow cat one thought it might help and best keep it bit more legal. Then put straight pipe section back in (so no muffler all straight pipe now) Finally it did help with what I was after. Straight pipe with no cat is a very annoying sound and also loud. Just by having the highflow cat and straight pipe the sound is nice not to loud. Nice tone and also can hear it whistle nicely also. Best of all slightly better spool up and response. Hope this helps anyone else going for a "3" system. The cat obviously works slightly at filtering some of the bad sound when going with straight pipe.

 

[Jnrsnav]

Sound clip please