Using words like "many" doesn't name specific exhausts nor does it substantiate proof to back each claim . Until they do it's simply a baseless assertion .

 

Thanks to all for the replies.

tejoe,

This was from Total 911, issue 52, page 72:

"Porsche has got its standard exhaust systems flowing so well in recent years that it is very hard for an aftermarket exhaust specialist to improve the sound without actually losing some power at the same time."


Agreed. As you can see from the above quote taken directly from the article that "many" was my word not the authors.

That paragraph, along with things I have picked up here and there reading this and other forums combined to form, in my mind, the question as originally asked in the OP.

Taken in context, the author was saying that for meaningful gains in hp, exhaust mods needed to be done in conjunction with intake upgrades and ECU remapping as a a package.

I wasn't able to quickly locate the other quote that led to my OP, but perhaps in a different article an author said something like: Aftermarket exhaust modifications frequently result in an increase in noise behind my head without any meaningful improvement to the power of the car.

I'll try to re-locate the exact quote and the context of that paraphrased statement as well.

 

As well as being more "free flowing" most aftermarket exhausts offer significant weight savings as well ....just my 2 cents.

 

Did they have any test results to back up a statement like this?

I would be surprised that a magazine would make a comment like this and not have a exhaust system test shoot out.

 

Don't believe everything you read. All you need to do is look at the 997 S factory header and look at Porsche's own X51 header. The standard equipment is not necessarily manufactured to produce maximum flow. Goes back to achieving correct cost and "target" HP objectives. Generic statements are difficult - and this certainly doesn't seem to apply to all 911 models. In the context of the E46 M3, I might believe it. Intake, exhaust, whatever, doesn't extact more than a couple of HP out of that engine. Engine mods on that car have very little value.

 

But isn't that the whole issue? "Maximum flow" can reduce power at lower RPMs when the exhaust velocity is lower due to the pulsed nature of exhaust flow. If you just swap in a less restrictive exhaust you can (and probably will) see gains on the top end but can (and probably will) lose torque at lower RPMs. Exhaust improvement is a lot more complicated than just making it less restrictive.

 

A lot more complicated than maximum flow, true, but it is also possible to have a system improvement that increases power and torque across the entire RPM band. I believe the X51 headers and less restrictive cats achieve that results on the S.

 

BrandX...I take you play guitar? I am a drummer, actually work in the industry as a rep.

 

Yep....guitar store owner and fashion photog:

Fat Sound Guitars


Who do you rep' for?

 

ha ha ha, I'm a lunatic!

 

Really.......?.......that surprises you? Magazines of all calibre make comments like this all of the time without exhaustive and conclusive testing (pun intended).

It was, more-or-less, an off-hand comment made out of context of discussing after market exhausts in general and based on everything I have read since my OP it is quite possibly true that manipulating the exhaust alone can cause a disruption of power at *certain* RPM's while increasing them, mildly, at other ranges.

Since I live at or below 6K 80% of the time I'd prefer not to have my 6K and below hp lowered.........especially just for a louder, "more exotic" sounding car.

I want to hear the engine, which is tough to do in the DFI cars, but I bought the car for it's performance first and foremost.....not it's under acceleration volume and tone

Moving on....so what I need perhaps, if I'm going to replace the center exhaust to open up the noise a bit *without* potentially losing power at any point in the band, is an upgraded intake, cats, exhaust and ECU mapping?

 

My first cousin is a guitarist (famous) . Ever hear of Twisted Sister ?

 

Great! I loved Twisted Sister back in the days .

 

How ironic....I have a twisted sister also !

 

Ahh, I know of your store. I am a rep for DW (10 years) and Zildjian...actually Zildjian starts for me on September 28th.