Quiet Exhausts

[yipming]

I have a MY07 Subaru GT-B wagon and a pair of HiTech Quads. Those did provide a fair increase in exhaust note that while louder isn't too intrusive. It did resonate/drone a bit at 2000-3000 rpm but is "livable".

However recently I had a de-catted dump and 3" centre pipe along with metal cat installed and tuned. The car became hellish loud. I think the volume probably doubled and resonated heavily within the wagon to the point things in the boot start rattling in sympathy. Funnily enough from the outside the exhaust don't sound too loud.

I am actually returning to have the stock muffler re-installed to (hopefully) quiet the car down. (Lucky I kept those)

But then I will be missing the quad tip look. So I suppose my question is, what are the quieter mufflers out there in the market?
I am thinking the STI quads might be my only choice.

BTW, I know I will be losing a few kW but with a new baby on the way I need the car to be quiet.


Thanks ahead for any advise
Alan.

[hamish_023]

I have TCP auto muffler's and 3" dump pipe and the car is mild on start up, almost stock when cruising and still not an overly aggressive noise when giving it the beans. I would say most of the noise is coming from the centre/y pipe.

[bass_straitener]

Have I got this right you only have a cat from the dump to the mufflers. If so I reckon you get a 13 or 14 inch resonator put in somewhere. This should fix your problem. I'll be getting the AVO mid section put in this month and maintaining the STI quads and don't expect a great increase in sound or resonance. The AVO mid section has a resonator. Check their website for pics.

[yipming]

Basically de-catted dump and a single metal cat in the mid. The XForce pipe does have a resonator and is probably around 13/14 inch long, but it isn't doing a lot though.
Michael (MSR) actually offered to put in an extra muffler in the mid pipe, effectively replacing the resonator but I fear that while it will reduce the volume, the issue will remain.

Forgot to mention that I have an auto, thus the slip point is usually around the dreaded 2-3k rpm which means every start up or going up a hill the car will reverberate like there's no tomorrow.

Might try the extra muffler but I got a "favour" Sunday fix from him to put the stockies back on.
However I do think the STI quads which should dial out most of the 2500 rpm resonance out with its "resonator chambers" design rather than the straight through/hotdog of HiTechs.

But otherwise it does make sense that the larger pipes with more flow would generate more noise.

[yipming]

Quick Update. Michael fitted the stock exhaust back on, replacing the HiTech and re-tuned.

The car is now stock quiet and actually made a bit more power than the HiTechs. Apparently with the HiTech the car won't accept any higher boost and with the stocks, Michael can up the boost to ~ 16 psi which he couldn't before apparently.

Anyhow, pretty happy with the result. Will most likely now hunting for anyone interested in trading their STI quads with my HiTechs.