Edgy01

If your 997 is equipped with the PSE (Porsche Sport Exhaust) system it quiets down between 45 kph and 75 kph (28-47 mph) to comply with strict Swiss noise abatement regulations.

schwartzwest

And let's add some fun:

I recently discovered why the ignition is to the left of the steering wheel on Porsches. Anyone care to jump in? (Dan I'm sure you know.)

Edgy01

Le Mans -- running start!

schwartzwest

Nugget

While we're answering trivia -- how come Porsche uses lug bolts instead of the more typical posts and lug nuts? I'm sure there has to be a good reason.

Edgy01

We covered the lug bolt vice lug nut issue several years ago.

Porsche used to always use lug nuts but switched over to bolts around 1999. I just don't know when for sure. I always had nuts on my older cars. OCBen (as an engineer) gave us a reasonable explanation. Do a search for that. I think he stated that the bolts are proving to be stronger.

MattAu

I wonder if it's European. My BMW 545i also has bolts. Whereas my Infiniti G35 has nuts. And if I recall correctly, my Jag S-Type and my Volvo S70 have bolts but I am not sure, that was too long ago.

THPorsche

My wife's MB R500 also uses lug bolts

Mike in CA

Was intrigued by your post as I remember when I installed a PSE on my 996 several years ago the system supposedly quieted down in the range you describe. To simplify installation I hooked up the mufflers without the vacuum control and let the little muffler bypass run "open" all the time, so I would never have noticed if the exhaust ran quieter in that speed range.

So this morning I had to try my 2009 C2S with factory PSE to see if it quieted in that range. With the windows down and PDK in manual 1st gear I tried two runs, one accelerating slowly and the next quickly from 15mph through the 28mph limit. Then I did the same thing in 2nd gear from 35mph though 47mph. Finally, I started from about 15mph in 2nd and accelerated both slowly and quickly all the way up through 47mph.

From inside the car I can't detect any dip in sound level. The exhaust note is linear all the way up through the rev range. Maybe the overall level of PSE in the latest cars is quieter so the dropoff isn't required. If so, to my mind they got it just right; a very sporty note that's not annoying to me, or apparently, the Swiss.

Edgy01

The sounds gets more severe as you accumulate miles. Perhaps you don't have enough!

Wills

The PSE exhaust is designed to run quieter at those speeds, you can unplug the control unit and bypass this feature....you guys must be having a laugh I thought everyone knew this? or maybe its just here in Europe.

brendo

why pay the premium for PSE if you can't turn it off? you can replicate the exhaust note with less expensive bypass methods if you want it all the time, no?

jnx

This is nothing new, the 996 was the same way.

Da Hapa

1. You can't actually replicate the sound with a bypass. It is similar, but not the same.
2. Many owners, for a variety of reasons, prefer to stay OEM and feel more comfortable with a Porsche designed, Porsche warrantied part.

brendo

^ fair enough. i went with PSE because it's OEM, and i like the sound and i can turn it on/off. of course, i think i was high, spending that money, but i'm no worse for the wear. i love it now.