Why Is The GT4 & GT4 RS ‘Muted’ When The New GT3 Is Not?
Discussion
As per above subject... I thought the 718 GT4’s sound was dampened because of regulations etc.
I presumed that this was the going to be the new normality for all NA Porsche’s going forward, however as per video below, the new GT3 screams in comparison to the GT4 and GT4 RS.
Is it because it is still a mule, and the final version will actually be ‘muted’ or is it likely to hold the sound that is in the video.
https://youtu.be/FbgUbLXunOM
I presumed that this was the going to be the new normality for all NA Porsche’s going forward, however as per video below, the new GT3 screams in comparison to the GT4 and GT4 RS.
Is it because it is still a mule, and the final version will actually be ‘muted’ or is it likely to hold the sound that is in the video.
https://youtu.be/FbgUbLXunOM
Simply down the exhaust system design.
The 718 has 2 muffling elements in the path... GPFs and then back box itself which is quite large and is also a silencer.
For the 911 you have the GPF, and then for the back box - they have been able to reduced the size/weight of the backbox and it doesn't have as much sound attenuation.
The GT3 also revs much higher, has a different valve train, and also the exhaust tips are close together.... all these elements have significant effect on sound frequency, tone which then we perceive as louder and higher pitched to a scream.
I mentioned it in another post... best description on the 718 4.0 sounds is that its like a NA version of the GT2 RS.
The 718 has 2 muffling elements in the path... GPFs and then back box itself which is quite large and is also a silencer.
For the 911 you have the GPF, and then for the back box - they have been able to reduced the size/weight of the backbox and it doesn't have as much sound attenuation.
The GT3 also revs much higher, has a different valve train, and also the exhaust tips are close together.... all these elements have significant effect on sound frequency, tone which then we perceive as louder and higher pitched to a scream.
I mentioned it in another post... best description on the 718 4.0 sounds is that its like a NA version of the GT2 RS.
Twinfan said:
That doesn't make sense. There's a Euro specifications dB limit so if the 718 didn't need the silencer it wouldn't have it, which is what the JCR replacement system does by replacing the silencer with straight-through pipework.
limits they get round with FLAPS at certain RPM's to pass the tests.I even though switchable exhausts were banned going forward, I am sure I have seen this EU reg.
I must have been mistaken or the law was not passed.
Twinfan said:
Flaps in the 718 system too. Why the 718 needs the silencer but the 992 doesn't I can't quite work out.
It’s because of what 911R said. Pre-GPF GT3/RS had 3 silencers. One each side plus the back box.
GPF RS/Speedster and 992 GT3 drops the 2 side silencers and just has the GPFs plus the backbox.
For 718 there was nothing they could remove, plus the change of tip location and the design of the engine, valves train, lower rev limit.
Thanks all... appreciate the detailed reply, albeit a lot of if flew over my head... but I get basic elements of what you are saying.
The GT4 RS didn't sound too bad in the video either, however I always think a PDK gear box on 'down shift' will always sound better that someone like me driving a manual car... even with auto blip on :-)
The GT4 RS didn't sound too bad in the video either, however I always think a PDK gear box on 'down shift' will always sound better that someone like me driving a manual car... even with auto blip on :-)
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