I've been running Borla and/or Magnaflow straight perforated mufflers with SS packing but I've been burning them up every year or so. I've been running my car more now, and my $280 borla muffler is getting louder only after a few months. My EGT isn't too crazy... around 1450*F at lean cruise and goes down to 1300*F with WOT. I'm sure it's up in the 1600's when I am playing with tune and rolling launch control.

That being said, I'm looking for a good 4" muffler that is narrow profile (at the most 6-7" thick at the body) that actually muffles the sound and can withstand our exhaust heat. I understand I'm almost asking to defy the physics, but I'm curious what the members have good luck with.

I'm not using resonator, just 2 mufflers in series. I'm now thinking of adding a resonator because the exhaust drone loves to shake my skull loose between 68mph-80mph without fail. Any successful resonator/muffler or 2xmuffler combo that has been friendly as daily driver for turbo 20b is the information I am seeking. Thanks in advance.

 

HJS from Germany.

 

Are you using the XR1s from Borla?

 

yea I'm using their straight through multicore muffler. It's still very loud. as for its longevity, to be fair, I also don't think it's designed for constant ignition cut traction control backfires in mind lol.

I am thinking of doing baffled muffler. I just don't have room to put another straight through muffler. or I may do inline cutout valve and perforate the butterfly valve so I can close it at cruising rpm and open it with boost... still thinking about it.

 

Try looking at this company
Performance Exhaust Systems
Jones Exhaust
JT4040
4" C/C, 6" Round, 20" Overall Length

 

SMB from australia do better quality stuff than any magna flow or borla ive seen. And they will build any muffler custom for you if you tell them what you want and still keep the price competitive. That said im pretty sure mine is louder now (2 years later) than when it was new (resonator and muffler) but that's with a fairly crappy rich tune. Im thinking I will cut them open and re-pack.

 

Lol.. Another area I am also working on with mine.. So my question is a bit different I have some unknown back box and silenced mid pipe fitted right now and as they are a bit of a mess compared to my custom 3" downpipe I have got some new bits in. My downpipe is proper 3" OD pipe I think the current midpipe and back if are too. I got a straight through midpipe sold as 3" but it turns out to really be 75mm OD. Not a big problem I don't think. Then I got an Apexi GT back box as I was told this was 3" as well bit it isn't.. It is 2.75" flange which flares straight to 3" pipe and then out to 3.5" after. While I am not happy about the size changes through the pipework will these restrict flow and cause a problem? I have a 50mm screamer pipe up front and not going for mega power.. basically whatever it makes at about 1bar boost. Thoughts?