eagle1960

I was seent 2 files to try. One did nothing and the other turned PSE off completely. The most recent file was about 3 weeks ago.

eagle1960

With the performance increase from the M-tune, I doubt any reduction will be noticeable. I am interested in the exhaust note impact.

Jimmy-D

For those that have this tune does it make the car jerky/nervous or is this tune smooth and linear.

Also - on the 2022 GTS I thought I read that the dual mass fly wheel was made stronger to help with the extra torque over the C2S. Any info on this??

Mb111

When you turn on the car the engine revs very high, and it's really, really loud and it lasts for about 2-3 minutes. It's loud enough that people have to raise their voices quite a bit to speak if they're around the car when it starts. If you want to leave your house early in the morning and not wake up anyone living on the side of the house that your garage is on, you want to turn this 'feature' off. When the valets bring me and my buddies' cars (my 911, a McClaren 720S and a Ferrari 458) to the front of my club after a round, mine was the loudest of the three during the cold start period, and the Ferrari is just plain loud and the McClaren has a noticeable low throaty constant growl. To me, the 911 cold start sound has a very high pitch to it - I hated it. But if you're in a quiet environment and you want everyone around you looking at you when you start the car then you'll like the attention. If you ask for it, the tune can turn this off - this is my daily driver so if I'm running errands around town my car doesn't scream 'look at me' at the dry cleaners or supermarket. I know for some that's the appeal of the car - to each, his/her own.

Tupper

How so?

It seems like there is so much conflicting information when it comes to car performance. On one hand, increasing flow and thus reducing back pressure causes turbos to spool up faster, thus better throttle response and overall slightly more power.

Now we are being told the opposite. Most exhausts on turbo charged engines that improve flow tend to see slight gains in power--this has been shown on Dyno, such as when Kies Motorsports tested the AWE exhaust (the one I have) on the BMW M340, with dyno proven gains in HP and torque, albeit small ones.

So how can the opposite be true at the same time?

Pad Bender

Valves are partially closed in Sport+ on TT/S...i presume that is for optimal performance.

Perhaps flow is less turbulent when not fully open?

BIGWORM

Less backpressure can sometimes take away low end torque.

PTS-BRG

I am not an engineer but, I am fairly certain that Porsche didn't build in cold start to make the neighbors upset or to make everyone say "look at me". I can only assume that it is done for some pre engine warm up and to get the car to operating temps more quickly to avoid any damage. I don't like it at all. I think its obnoxious and in my garage it does reverberate and bother the neighbors. That being said, its there by design for a reason and I am more concerned about doing long term damage to the car with premature wear than I am about disabling it to make my neighbors happy. It is not 2-3 minutes, its probably less than 1 minute but, its programmed like that for a purpose so Its not being un programmed. Its not like Auto Start Stop that is there for fuel economy, that I have no problem removing

Tupper

^ Then why do dynos taken for larger bore aftermarket exhausts that have no valves (like the AWE exhaust I mentioned) show the opposite?

aquanaut

It's for emissions purposes. No need to overthink it.

PTS-BRG

aquanaut: So your position is that the higher revs are necessary to heat up the cats in order to more quickly burn off fuel? Im certain that may be part of it, but I wonder why it needs to rev so high? Wouldn't the car sitting at normal idle also warm up the cats in the same time period? I would love to hear M engineerings take on this..

aquanaut

Correct. There's good data on this (like: Reducing Cold-Start Emissions by Catalytic Converter Thermal Management (nrel.gov)) which is why basically every car does it now.

BIGWORM

Im not sure Tupper. I just know that having less back pressure can sometimes take away low end grunt. Perhaps it shifts the torque/HP to the top end. But I'm not 100% sure.

AlterZgo

Most of the increased sound happens not necessarily b/c of higher revs (which aren't really that high) but because to heat up the catalytic converters as fast as possible, waste gates are fully open thus bypassing the turbochargers which makes the car basically sound like a naturally aspirated car during cold start. N/A 911s have always been louder than turbocharged 911s b/c the exhaust gas is not routed through the turbos which naturally quiets the noise.

As for why not just warm it up with a normal idle, the problem is, when catalytic converters are cold, they are not effective so this is the time when the car pollutes the most. The cold start process makes the catalytic converters functional much faster than just normal idling. So, if you code in this feature to eliminate cold start, your car will be quiet, but it will pollute more than stock w/ cold start.

Pad Bender

Well guess im gonna have to explain that to the neighbors.