StormRune

It's been around a long time. I recalled reading about it in an old Car & Driver or MotorTrend or some such publication ages ago. Back in the 50's and 60's there were numerous cases of people succumbing to CO1 seeping up though the floorboards and trunk into the cars of the day when exhausts and bodies were more rust-prone, so I imagine this was a response to that. I think kids in the back seat were more susceptible.

I found an old research paper making mention of it way back in 1972.
"Beginning with 1971 models, some automobiles have a fan-operated ventilation system that circulates fresh air through the passenger compartment and produces a slightly positive pressure designed to keep out exhaust fumes."

https://ajph.aphapublications.org/do...JPH.62.11.1463

StormRune

I agree with the others that nothing you do in the way of a more open exhaust is going to make the popping more moderate... it will just be louder. A lot louder based on my experience with 991.1 exhaust mods. I had my son do some drive-bys and dump throttle with my prior 991.1 aftermarket exhaust and it was like someone set of a round on M80s. I went back to stock after that. A map is of course a possibility if someone is doing a mod that way... assuming you are okay with the engine-related warranty issues with a tune.

The nice thing about Normal mode in a 991.2 in manual mode with PSE on is that it provides a modest off-throttle burble in the exhaust but omits the pops. I find myself much happier with Normal mode in the 991.2 in around-town driving due to the torque and burble. I was never very happy with Normal in a 991.1 except when warming up the car... the low-end torque just didn't support much responsiveness there.

Like hbear first said, there are no pops in Sport Plus either but the burble goes away too. But Sport Plus has its own interesting sounds. It keeps the turbos spun up faster all of the time, so you hear the turbos spool up more than you do in the other modes. To quite a few here that whistle is a minus... but I'm a fan. You can really hear the difference in turbo whistle in the different modes if you try each of them out in an empty area of a parking garage and just do simple light accelerations from a near stop. The sounds really come back at you in there.

Like someone noted in another thread yesterday, the retarded-timing / throttle-closure trick that Porsche uses to keep the turbos spun up more In Sport Plus creates its own interesting off-throttle sound. Its not as dramatic for sure, but interestingly different.

So in summary here are the audio effects for a 991.2 (with the PSE open for best effect).

• Normal Mode: Burbles, no pops, less spool-up whistle
• Sport Mode: Burbles, pops, less spool-up whistle
• Sport Plus Mode: No burbles, no pops, more spool-up whistle when coming on throttle. Also has its own off-throttle sounds.

Avalon911

"Set key"

StormRune

Nope. The fan will still come back on at its low setting regardless. It won't let you save it turned off. It appears common in the German cars at least. The same painful long discussions have taken place in the BMW forums as well.

2000se

Fan = as stated above..nothing wil fix that.

Radio - Here is how I did mine.. My radio does not come on when I start the car.
While the car is running, press and hold the volume **** in on the radio. It should completely cut the radio off after about 5-10 secs (can't remember how long). Once the radio is off, set your memory as normal on the door. that should do it.

lazar96

Thanks for such an in-depth explanation, it's really cleared things up! Only other thing I want to know now is how to turn off auto blip. Can you advise?