Dual vs. Single-Outlet exhaust. Performance gain?

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I want a new exhaust for my 930. My OEM muffler is pretty dented from the PO, so I want to treat myself to something that sounds real nice (louder), and adds some performance. I don't want, or need, bling.

Stock, I've got a "single-out" (well, two pipes on one side of the car coming out of one muffler). Aftermarket offers "dual-outlet" designs.

Do they offer more power?
Are they louder?
Will my turbo spool up faster?

I've been looking at this unit from Fabspeed. It appears to only have one side going through the muffler:

[Steve@Rennsport]

Hi:

Generally speaking,......the only difference between single and dual outlet sport mufflers is noise.

In the case of the 930, dual outlet mufflers DO make a difference in throttle response, boost lag and power output.

Having tried several products on many different 930's over the years, the best single modification to a 930 is the installation of the header/heat exchangers make by either GHL or B&B and the dual outlet muffler. Nothing offers as much bang for the buck and overall performance boost and makes a big difference in reducing boost lag.

Its not cheap, but VERY well worthwhile.

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Originally posted by Steve@Rennsport
"...the best single modification to a 930 is the installation of the header/heat exchangers make by either GHL or B&B and the dual outlet muffler."

Thanks, I appreciate the reply.

Am I assuming correctly that a GHL header/heat exchanger will bolt up to a Fabspeed muffler? I really like the GHL header/exchanger, but funds are limited right now... so I was going to do this piecemeal and start with the muffler.

In effect, I'd bolt the Fabspeed muffler to the OEM header/exchanger. At a later date, I'd replace the OEM header/exchanger with the GHL.

[Steve@Rennsport]

The header/heat exchangers bolt to the engine and turbocharger. The muffler bolts to the turbo outlet,.........

Due to performance of these mufflers and other issues, I do not use nor recommend any Fabspeed products so I cannot say for sure that it will fit the car and locate the outlet in the original position.

Personally, I'd install the dual outlet GHL muffler and add the header/heat exchangers when you can swing it.

[911Sickness]

Note that many people (myself included) have had fitment issues with GHL mufflers/headers. To get a true, clean install, you may need to modify the right side outlet. I've been told that the problem ultimately lies with the headers and the muffler will fit perfectly on your stock headers.

I concur with Steve about the performance gain tho, and I'd definitely go with GHL again in spite of the fitment issues.