I cannot compare a 991.1 S to a 4.OGTS, but moved from a 991.1GTS (PDK) to a 718 Spyder 4.0 (manual). I think these two cars are pretty comparable with the main differences being the engine position and the feel that engenders. The 911 was more forgiving IMO. I can break the rear end of the Spyder loose in almost any conditions, but the 911.1 GTS was rock solid (except in rain). The Spyder is a hoot, but so was the 991.1GTS. They seem equally fast to me (actually the PDK car was faster but that's down to my weak clutch work). The stock 991.1 GTS definitely sounded a million times better than my Spyder, even with a Kline inconel OAP+muffler.

 

I have/Had a bunch of Porsche cars including both platforms.
for some odd reason , my least favorite one was 991.1 C2S .That was a 2014 MY.

 

I was tracking til this right here. A "million times" better? Really?

edit- I'm bored at the moment so decided to go double check with some YouTube vids... and yeah, the 991.1 sounded really damn good lol.

Not sure about the "million times" thing though. Maybe you don't need that Kline setup anymore, may as well just give it to me. PM for shipping info.

 

I've got the Kline inconel OAP and Rear Section on the way, and this comment is scaring me....

Had two 981s and they sounded soooooo good that I never even thought about modifying the stock PSE.

Here's to hoping that I didn't just waste 8K!

The sound is the main thing that I would expect the 991 to do better - and it's a big piece of the puzzle for sure...

 

I just took delivery of a CGTS 4.0 PDK June 1st. The car it replaced was a 2016 991.1 GTS PDK.
The Cayman is much more fun. Everything just feels balanced and “right” in the 718.
Honestly, both platforms are great, but for me, right now, the Cayman is the perfect car.
one caveat (and hopefully this won’t be a factor in your choice), the “Porsche crowd” does NOT have the same regard for the 718 as they do for the 911, ANY 911. At PCA events my Cayman is just another parked car. My 2016 Carrera GTS was a real crowd pleaser. So be it.

 

Why would the 911 sound vastly different than the Cayman when both are NA flat 6 engines, assuming both have same or similar exhausts?

 

There are a few reasons; I won't pretend to be the expert on automotive acoustics but am aware of some key differences. FWIW I'd be interested if anyone comes across this thread and can point us towards some good material that more effectively explains why some engines sound different than others but I'll weigh in with my .02 based on relatively low amount of research, with that caveat noted.

Worth mentioning because not everyone will have a Kline inconel exhaust on their 718s, is the particulate filters. From what I understand, even the US spec cars are at least somewhat affected by emissions regulations for the 718 (read somewhere that the particulate filters were present in the system but "inert", whatever that means). That does have a significant impact on the external noise.

But since the poster mentioned he has the Kline inconel setup vs his stock PSE 991.1 GTS, it's important to note that the particulate filters (which to my understanding reside in the section of pipe over the axles, commonly referred to in 718 parlance as "over-axle pipes" or OAPs) have been removed in the Kline system (*I think they've been removed... there's definitely something in there but I think it's a hi-flo cat. Somebody keep me honest if I'm mistaken pls). So the different in exhaust note comes down to the actual design and material used for the pipes themselves, plus other engine characteristics. It makes sense that the mid-engine cars sound a bit different than the rear-engine cars just due to the orientation of the engine as it relates to the termination of the exhaust pipes (and the distance from the driver/acoustics of the cabin space for noise inside the car).

These "engine characteristics" is where I'm veering into some substantial guesswork, but I imagine things like intake design, camshaft profile (valve lift/duration), firing sequence, compression ratio, etc. etc. all play a role.

Plus I also think there's some funkiness in the design of the stock 718 system where the two banks from each cylinder head remain separated, and this can only be remedied by an aftermarket exhaust. I'd need to do more research on that specific element though... I haven't done much because frankly I'm leaning towards a Kline system myself for my incoming BGTS.

The practical breakdown of all of this is that you can indeed notice a difference. It's even evident in YouTube videos... it's not that Spyder sounds bad, at all- it's just that the N/A 991s just sound better. It's like on a scale of 1-10, 1 being a Diesel pickup and 10 being a Lexus LFA, the 991 scores about an 8.5, the Spyder about an 8. With the Kline, I'd put it at an 8.4... (subjectively of course).

In any case, definitely not "a million times better"... that is what is colloquially referred to as "hyperbole".

 

Yes, you are correct that many things affect engine sound of all engine types (heads, cams, exhaust routing and design). I thought we were comparing two flat-6 engines with similar aftermarket exhaust (same brand, but of course different routing) and people were stating one was a million times better than the other. I was curious about that.

BTW, in the US, the GPF's are inactive but do muffle sound a lot. That's why just going with aftermarket OAP's to replace the GPF really wakes the car up. Combine that with an exhaust valve controller and it transforms the car IMO. Going aftermarket with the rest of the exhaust becomes a personal preference depending on what you're after. Dyno numbers, altering where the peak HP is slightly, or just different pitch/sounds. Some exhausts are really nice. I'm not sure they are worth the money, but I am a VERY FIRM believer in: to each, his own. And I respect everyone's choices in mods, even if they may differ from my own.

I was at the Caffeine and Carburetors Cars & Coffee in New Canaan, CT this weekend where you will see some of the most expensive cars in the world next to the most modified, crazy cars next to a HUGE selection of collectible cars in stock form from all years. Some guy had a 1970 Buick Skylark set up as a drag car, but really looked like something built on a cable TV show. Twin turbos, tubbed rear end, duct work feeding multiple radiators in the trunk, and a full video surveillance system like he was driving from inside the pentagon. It was crazy! Amazing workmanship. I appreciate the talent. Would I want to own it? Not on your life. But I can appreciate his passion, and his willingness to throw money at his hobby.

 

I'm there with you on "to each their own", for sure. I've been all over the map personally even though mostly financially limited until relatively recently. I started out with muscle cars and a 68 chevelle, then switched to Japanese imports with a handful of 240SX's, then moved to BMW, back to Subaru, back to BMW, then finally to Porsche lol. I'm sure most of us on here have similar stories.

Back to engine sounds, the only thing the 718 4.0 and the 991.1 3.8 have in common to my understanding is the flat 6 orientation. Pretty much everything else is different... so you get two distinct sounds.

I think another strange thing about the 4.0 is that it was originally designed for forced induction; it is an iteration of the 3.0 in the turbo 911s after all. I'm not sure how that factors into how the engine sounds, but it does indeed seem to be missing some of the character of the earlier N/A flat 6 engines in the 991 and 981 generation cars... it makes up for it in many other ways but the exhaust sound is just a bit different. I haven't actually driven a car with a 4.0 yet (a few more weeks and that will change!), but from what I gather the induction noise is actually better in the new cars.

End of the day you're mostly right though. These are infinitesimal details that only hardcore lunatics would notice.

True story- I've had more than one occasion where people have told me how amazing my 2.5T 718 GTS sounds. Kind of reaffirms my suspicion that the only reason the turbo 4 engines get so much criticism for engine sound is because us "Porsche people" have been trained to expect a different sound... the rest of the world really doesn't care nearly as much as we do apparently.

 

The 911.1 GTS has the same engine as the 981 GT4 which many have said in stock form blows away what the 718 GT4's sound like. I have both a 981 GT4 and a 718 Spyder with arguably the "best" sounding high pitch GT3 like exhaust setup on the Spyder(JCR + OAP's) while the 981 GT4 has a stock muffler + some cheap race headers and the 981 GT4 still sounds better.

If you don't believe me, here's a video of a stock 981 GT4 compared to a Kline Iconel 718 GT4:


But to me personally both of those cars don't sound like what a GT car should sound like which is a high pitch RSR type sound. Only way to get this on the 981 GT4 is to run Fabspeed Race Headers or a JCR Exhaust on the 718 GT4/Spyder.

 

We had a 981S PDK. We have a 991.1 S 7MT and a 718 Spyder MT.

If you can buy both right now and don’t need the rear seats then the 4.0. If the 4.0 is a waiting-for-an-allocation car then the 991 ‘cause unless you are a whale you might not get an allocation before production ends.

I prefer the old PCM. CarPlay is overrated. The new PCM is a coked-up ‘stripper: a hot mess. The old PCM was functional if not pretty.

 

hope you’re right - I recently went looking for a 991.1 S and ended up finding a GT4 allocation for December! (But I am a CarPlay believer)

 

Good video. I opened it twice, two windows, and compared the sound of each car as they took off from the side of the road. They're different, but to my ear, I wouldn't say one is more pleasing than the other, just a little different.

Thanks for sharing this video, it's a good comparison.

 

To take it another step further, this is the "best"(which I define as most GT3 or RSR type high pitch exhaust sound possible) for both the 981 GT4 engine(same as 991.1 GTS) and the 718 GT4/Spyder: https://imgur.com/a/S9aoucJ

One costs $1500(981 GT4) and the other takes 6k+(718 GT4/Spyder) with exotic materials to achieve.

 

Within the niche of sports cars the 991.1S and GT4 are very different experiences. One really isn't a substitute for the other. If trading out from the wheel of a people mover or pickem'up then they are the same.

"Belief is so often the death of reason"

Carplay is poorly integrated - no display in cluster TFT, PCM switching to/from other functions (tuner, etc.) very clunky. It operates by touch only.

Even Sir Jony thinks it's (touch-centric auto HMI) a bad idea: https://www.drive.com.au/news/former...car-interiors/