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Well its official.

John at BGB has been bugging me to set up DashCmd and do some logging in preparation of the new tune I am about to try.

I set up a Lambda gauge and did a test run. DashCmd is pretty cool.

What I saw was, in Normal mode when you back off the throttle you see the lambda change immediately and the exhaust run lean.

With PSE on in sports mode you see the Lamda go rich while it Bubbles and Pops and as soon as the popping stops in goes lean.

So PSE on, means more fuel consumption. I have no idea how much, I suspect minimal but it does use more.

I guess that this relates to the ECU update that gets done when you do an aftermarket PSE update.

:cheers:
 
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Nice piece of info, you've confirmed what heard about the Pops and crackles. It does inject fuel during the cut off. So yes more fuel consumption.
 

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It does inject fuel during the cut off.
It's probably closing the throttle plate abruptly and completely rather than closing it more-slowly so as to ensure complete burn of fuel during the transient of throttle closing. The latter is why cars made in this century don't have cables that connect the go-pedal to the throttle plate; it's an emissions control necessity.

Thinking a bit further, today's direct-injection engines (as opposed to port-injected) probably allow good-enough control of fuel that even in transient conditions there is no extra fuel. So I would bet that the PSE software closes the throttle plate and reverts to a fueling algorithm that is reminiscent of how fuel control worked last century.

The real question is: How long will The Smog Nazis continue to allow manufacturers to put buttons in cars that result in more emissions than necessary?
 

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Good to know. So if I'm going to use PSE all the time, I should also leave auto start/stop enabled so I can call it a wash. :D
 
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Well its official.

John at BGB has been bugging me to set up DashCmd and do some logging in preparation of the new tune I am about to try.

I set up a Lambda gauge and did a test run. DashCmd is pretty cool.

What I saw was, in Normal mode when you back off the throttle you see the lambda change immediately and the exhaust run lean.

With PSE on in sports mode you see the Lamda go rich while it Bubbles and Pops and as soon as the popping stops in goes lean.

So PSE on, means more fuel consumption. I have no idea how much, I suspect minimal but it does use more.

I guess that this relates to the ECU update that gets done when you do an aftermarket PSE update.

:cheers:
Nice finding BJR, I noticed that with my car. I am not getting good mileage per gallon, I figured it is a new car and It will get better later. I am lucky if I get 15 mpg. I do both freeway and street driving. I noticed when I use the PSE its even worse. I am not complaining on the mpg so much as I didn't get the car to save fuel but to have FUN, but the mileage is not even close to what Porsche says specially when the PSE is used. For me it is worthy.

Thanks BJR and awesome parking spots you get in public places; nice color of your car. That was one of my top threes choices of colors before I finally ordered mine.
 

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PSE is on in my Cayman S about 95-100% of the time. I have found my average overall mileage is about 20 miles to the gallon. Around town 15.5-18 and higher on the highways.


Nice finding BJR, I noticed that with my car. I am not getting good mileage per gallon, I figured it is a new car and It will get better later. I am lucky if I get 15 mpg. I do both freeway and street driving. I noticed when I use the PSE its even worse. I am not complaining on the mpg so much as I didn't get the car to save fuel but to have FUN, but the mileage is not even close to what Porsche says specially when the PSE is used. For me it is worthy.

Thanks BJR and awesome parking spots you get in public places; nice color of your car. That was one of my top threes choices of colors before I finally ordered mine.
 

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Discussion Starter #11
No, auto stop is disabled during "sport" mode. sorry weasel
Ah but you run in normal with Auto Start/Stop and turn on PSE. That would be a weasel wash.:hilarious:
 

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Good to know. So if I'm going to use PSE all the time, I should also leave auto start/stop enabled so I can call it a wash. :D
PSE without sport mode enabled is essentially a dummy button. auto start/stop is disabled once sport mode is activated.
 

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PSE without sport mode enabled is essentially a dummy button. auto start/stop is disabled once sport mode is activated.
For real? If you just get in a drive, and only hit the PSE button, it doesn't make a difference in the noise??
 

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Others may disagree, but I'm certainly not hard of hearing. I actually brought the car in because I thought something was wrong with it when I first got it. Unless you're in sport mode, PSE is barely (if at all) audible.
 

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I shall report on whether this is also true for GTS models just as soon as I can. :D
 
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Others may disagree, but I'm certainly not hard of hearing. I actually brought the car in because I thought something was wrong with it when I first got it. Unless you're in sport mode, PSE is barely (if at all) audible.
You can't tell the difference until the engine is greater than 3500 rpm. Try driving steady at 5500 rpm and turn on and off the PSE. You can tell easily.
 

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That would be swell. Will definitely give it a try again.
 

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You can't tell the difference until the engine is greater than 3500 rpm. Try driving steady at 5500 rpm and turn on and off the PSE. You can tell easily.
Thank you

Well that is something definitely different between the 981 and 991 cars. Strange they would do that.

If you click the PSE button on the 991 it immediately goes into a deeper tone. Sport add the sound symposer to the cabin and the software adds more burbles. Sports plus adds additional burbles and more raw fuel being dumped.

Here is a Carrera 3.4. Notice the tone change when he turns PSE on at 46 seconds. Its clearly different.


Here is a 3.8. Now watch at 10 seconds, the tone clearly changes


The 981s do not behave this way? Interesting but I don't understand why not.
 

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Wait... does the sound symposer have a valve as well? I thought it was just a hole. :D
 
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