Pappagray

Hey everyone,

curious is there a way to start up the PSE in quiet mode? My catless T is pretty noisey, and would be nice if I could start it up in quiet mode

Jack F

It that I am aware of. Cold start is always louder for a short bit.

asellus

Nope. It's vacuum operated and you don't have any vacuum to operate it when you first start the engine.

Pappagray

I’m surprised someone hasn’t come out with a controller for it. Few other cars I’ve owned I’ve been able to buy aftermarket controls that completely control the exhaust. Wonder what’s different about the Porsche setup

asellus

It's vacuum operated.

You can't tell it to be closed unless you show the actuators a vacuum.

Pappagray

Has nothing to do with vacuum. All my
corvettes were vaccumm operated. You
fire it up, it’s loud for like 1 second before the vacuum builds and makes it quiet. My 911 is loud for like 10-15 seconds before it comes down. There is some parameter that is making it stay open, or something during start up that is making it loud.

it would just be nice to start it up quiet on the early mornings

tilac999

It's for emissions, for the cats to fire off quickly. Nothing you can do about it.

justabout

They probably open the engine exhaust valves early to dump more heat into the exhaust to light the catalyst. You can’t control it. My cayenne with sport exhaust is super loud on cold starts regardless of sport exhaust setting.

asellus

I'd imagine if it was a simple parameter to change to show vacuum to the actuators earlier, APR's "quiet tune" would have done it.

There was no difference in startup loudness on my 991.2 with that tune. Always that 5-10 seconds of loudness.

There's also the cold start enrichment to heat up the cats, mentioned above, which creates a much louder exhaust note. Most cars I've futzed with you can tune that out.

Pappagray

thanks for the incite guys