Exhaust note change in Sport mode
#16
Burning Brakes
I've always assumed it's the more aggressive throttle mapping, providing a richer air/fuel mixture, with the extra igniting during deceleration.
#17
Rennlist Member
Since Sport Plus is the "fastest" mode anyway, they tuned them out.
#18
Burning Brakes
When I had a Jaguar F-Type, it was famous for gurgling and popping, and that was the explanation given by Jaguar engineers.
#19
Rennlist Member
No, I didn't say it was providing more air/fuel once off throttle, it's just cooking off the excess remaining after coming off throttle in Sport and Sport +.
When I had a Jaguar F-Type, it was famous for gurgling and popping, and that was the explanation given by Jaguar engineers.
When I had a Jaguar F-Type, it was famous for gurgling and popping, and that was the explanation given by Jaguar engineers.
Sam or other tuners can weigh in, but pops / cracks in modern cars are all in the tuning in whatever mode. People actually pay tuners to tune their cars to do that crap...excessively at times..
The older race cars or hot rodded cars poped and cracked due to the extra fuel from the combustion fueling, and not so much from deliberate tuning for it.
This is just the way I've always seen it... but I'm not a tuner....who knows.
#20
Burning Brakes
I'm obviously not expressing myself well.
Mine is running the original OEM tune, and I heard no audible gurgles and crackles with the OEM exhaust in SPORT or SPORT +. That giant suitcase muffler was probably just making them inaudible.
The ONLY change to my car was swapping out the OEM muffler for a Speedtech X-pipe w/ no mufflers, and voila, gurgling and crackling during deceleration in Sport, but not in Normal mode.
The OEM throttle mapping and air/fuel mixture is changed for performance, not sound effects. Ample proof of that is comparing your mpg in Normal and Sport modes. The sound effects are just a benefit (or annoyance) with an X-pipe depending upon your perspective.
Mine is running the original OEM tune, and I heard no audible gurgles and crackles with the OEM exhaust in SPORT or SPORT +. That giant suitcase muffler was probably just making them inaudible.
The ONLY change to my car was swapping out the OEM muffler for a Speedtech X-pipe w/ no mufflers, and voila, gurgling and crackling during deceleration in Sport, but not in Normal mode.
The OEM throttle mapping and air/fuel mixture is changed for performance, not sound effects. Ample proof of that is comparing your mpg in Normal and Sport modes. The sound effects are just a benefit (or annoyance) with an X-pipe depending upon your perspective.
Last edited by Foosh; 06-22-2024 at 03:22 PM.
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Big Swole (06-22-2024)
#21
Rennlist Member
I'm obviously not expressing myself well.
The OEM throttle mapping and air/fuel mixture is changed for performance, not sound effects. Ample proof of that is comparing your mpg in Normal and Sport modes. The sound effects are just a benefit (or annoyance) with an X-pipe depending upon your perspective.
The OEM throttle mapping and air/fuel mixture is changed for performance, not sound effects. Ample proof of that is comparing your mpg in Normal and Sport modes. The sound effects are just a benefit (or annoyance) with an X-pipe depending upon your perspective.
If the "Fastest mode (sport plus) has the "most" fueling, then why no pops / cracks?
So, I concede that Porsche or any manufacture these days / recent past that make those pops cracks, purposefully TUNED those sounds into the car in whatever mode they saw fit.
The stock exhaust just masked it IMO.
#22
Rennlist Member
Further more...Sam and other tuners can "Tune" the pops / cracks OUT completely...or seriously reduce them.
Which is what Porsche did in the Sport Plus mode (fastest mode)
Which is what Porsche did in the Sport Plus mode (fastest mode)
#23
Rennlist Member
Under "Backfire" it shows "ACTIVE for Sport mode abut not in Normal / Sport Plus.
#24
Burning Brakes
Yes, as I said, the stock exhaust was clearly masking the deceleration sound effects. I honestly don't know what Sport + does other than keep the revs very high in PDK auto mode, and of course, it gives you a that temporary extra boost for more torque in launch mode.
No doubt that there are some differences between the .1 and .2 in terms of OEM tunes. CAFE regulations also tightened over the years between them, so perhaps some tweaks were made.
EDIT: interesting chart you posted above showing "backfire."
No doubt that there are some differences between the .1 and .2 in terms of OEM tunes. CAFE regulations also tightened over the years between them, so perhaps some tweaks were made.
EDIT: interesting chart you posted above showing "backfire."
Last edited by Foosh; 06-22-2024 at 03:48 PM.
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Big Swole (06-22-2024)
#25
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Hey guys. Yeah, these cars change engine tuning settings, which makes it seem like a valve switches on the exhaust sound but it’s actually in the head and in the timing. Also, VTG vein position. There are specific parts of the map called “impulse combustion“ where you can change how aggressive the pops are in every setting. Newer cars usually have this as opposed to changing timing settings and adding fuel on some other/older cars. Some people still don’t believe it when we tell them there is no valve on the exhaust ha ha.
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#26
Rennlist Member
Yes, as I said, the stock exhaust was clearly masking the deceleration sound effects. I honestly don't know what Sport + does other than keep the revs very high in PDK auto mode, and of course, it give you a that temporary extra boost for more torque in launch mode.
No doubt that there are some differences between the .1 and .2 in terms of OEM tunes. CAFE regulations also tightened over the years between them, so perhaps some tweaks were made.
No doubt that there are some differences between the .1 and .2 in terms of OEM tunes. CAFE regulations also tightened over the years between them, so perhaps some tweaks were made.
And yes, it changes the PDK shift strategy and the extra "boost" for more TQ.
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Foosh (06-22-2024)
#27
Rennlist Member
Hey guys. Yeah, these cars change engine tuning settings, which makes it seem like a valve switches on the exhaust sound but it’s actually in the head and in the timing. Also, VTG vein position. There are specific parts of the map called “impulse combustion“ where you can change how aggressive the pops are in every setting. Newer cars usually have this as opposed to changing timing settings and adding fuel on some other/older cars. Some people still don’t believe it when we tell them there is no valve on the exhaust ha ha.
Thanks Sam!! I knew the tuner could clear it up.
All in the tuning for sure, and I think I mentioned in this thread or the other one going on about this topic, that the exhaust note is changed by the tuning controlling the VGT veins. It may have been on the other thread with the guy who just bought the red TTS Cab.
Last edited by Big Swole; 06-22-2024 at 03:42 PM.
#28
Rocky Mountain High
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I think this is done to make the car sound a bit more racy. Historically, many race cars had the timing advanced because this produced more power and efficiency in the high RPM ranges seen when racing. The result of this advance to the timing is unburnt fuel being ejected into the hot exhaust system when decelerating, causing the classic overrun pops and burbles. Porsche simulates this overrun chatter with tuning/programming. I actually like it most of the time, but if I get sick of it then I can always drive in “normal” mode.