718 GT4?
05-16-2019, 10:53 PM
#6901
Rennlist Member
05-16-2019, 11:17 PM
#6902
Burning Brakes
05-17-2019, 10:52 AM
#6903
That video had a lot of GT4s including one of the earlier ones that we've seen. Not sure if this is all recently shot but here's what I think we see and hear:
- Some of the GT4s are definitely NA,
- The GT4s' exhaust seemed quieter/muffled but still NA in most of the segments of the video,
- The speedster's exhaust is a little quieter compared to the GT3 RS's and 992 GT3 exhaust,
- The 992 GT3 videos we are seeing might not be with the GPF,
- The 991.2 GT3 RS is awesome,
- The 992 GT3 is going to be awesome if what we see in this video is a 992 GT3 with GPF.
05-17-2019, 02:24 PM
#6904
Originally Posted by Teo
from PFF:
Strange GT4 at 7.20...
Strange GT4 at 7.20...
The 718 GT4 sounds good. One of the passes it has the same tone as the 3.8 imo. I wonder if they are running one with a 3.8 in it and a 4.0. Sometimes at low revs it has that deeper 4.0 sound imo.
Also the RS3 pass at one point sounds pretty damn good. I might pick one of those up. dunno.
05-17-2019, 05:06 PM
#6906
Race Director
dude awesome video! never seen that footage. The GT4 sounds good. It's just low revs / off throttle at 7.20 I think.
The 718 GT4 sounds good. One of the passes it has the same tone as the 3.8 imo. I wonder if they are running one with a 3.8 in it and a 4.0. Sometimes at low revs it has that deeper 4.0 sound imo.
Also the RS3 pass at one point sounds pretty damn good. I might pick one of those up. dunno.
The 718 GT4 sounds good. One of the passes it has the same tone as the 3.8 imo. I wonder if they are running one with a 3.8 in it and a 4.0. Sometimes at low revs it has that deeper 4.0 sound imo.
Also the RS3 pass at one point sounds pretty damn good. I might pick one of those up. dunno.
05-17-2019, 07:36 PM
#6907
We all agree there is a huge variance in the sounds of the GT4's we see in the videos. The GPF appears to drastically alter the sound of the car if that is what we are hearing. The first one you see in that vid has what I would call a deeper version of the original GT4's sound. Could be GPF. Could be it's a larger bore/longer stroke variant of the previous motor. Who knows. The one at 1:36 and 2:18 sounds more like the original GT4. The one at 3:29 sounds entirely different from the others. It also could all come down to the new PWW controlled exhaust valves as well. They are apparently no longer just opened or closed as on the previous gen car.
One observation I would make is why does the new GT3 in black sound exactly like the previous gen GT3 leaving the pits behind it? Would seem if it had the filters on it the that note would change there as well.
One observation I would make is why does the new GT3 in black sound exactly like the previous gen GT3 leaving the pits behind it? Would seem if it had the filters on it the that note would change there as well.
Apparently the Speedster is not getting GPF’s in US. Many of the recent Speedster reviews have this info.
Interestingly enough, cars bound for the United States will not get the particulate filters but instead will have devices meant to mimic the restriction of the exhaust-choking filters to simplify engine tuning.
Note that in place of the particulate filters, U.S.-bound cars will get an inert substrate that simulates the filters' back pressure.
05-18-2019, 01:17 PM
#6908
Three Wheelin'
Good to know we won't get the dreaded PF. Let's hope that those inert devices don't impact the sound one bit! Since we've heard different sound profiles, there is hope!
05-18-2019, 01:48 PM
#6909
The GPF is an integral part of making noise targets with the smaller, lighter muffler. In the US it’s replaced with a mesh that must re-create both the back-pressure and at least some of the noise reduction. Personally I wouldn’t hold my breath...
05-18-2019, 05:54 PM
#6911
Three Wheelin'
Thanks, Pete. Since we don't have a regulatory requirement for reduction in noise, the mesh doesn't need to diminish the noise level? Or, is reducing back-pressure automatically cuts the noise as a side-effect? One member posted hearing the engine in a closed garage. He commented that the US-spec car sounded deeper, at low RPM, than 981. He alluded the sound as "better".
05-18-2019, 06:16 PM
#6912
Rennlist Member
Here’s hoping the ROW cars don’t even have the back-pressure and sound deafening mesh at all.
If I recall correctly in Pete’s 991.2 Speedster thread he stated that Porsche indicated the mesh material for ROW cars was neccessary because of the independent throttle bodies specific to the speedster motor, as the ITBs and Particulate filters/backpressure mesh were directly related.
I highly doubt that the GT4 will be getting ITBs, so in that case technically there would also be no need for the mesh for ROW cars. Just being optimistic
If I recall correctly in Pete’s 991.2 Speedster thread he stated that Porsche indicated the mesh material for ROW cars was neccessary because of the independent throttle bodies specific to the speedster motor, as the ITBs and Particulate filters/backpressure mesh were directly related.
I highly doubt that the GT4 will be getting ITBs, so in that case technically there would also be no need for the mesh for ROW cars. Just being optimistic
05-19-2019, 10:14 AM
#6913
Here’s hoping the ROW cars don’t even have the back-pressure and sound deafening mesh at all.
If I recall correctly in Pete’s 991.2 Speedster thread he stated that Porsche indicated the mesh material for ROW cars was neccessary because of the independent throttle bodies specific to the speedster motor, as the ITBs and Particulate filters/backpressure mesh were directly related.
I highly doubt that the GT4 will be getting ITBs, so in that case technically there would also be no need for the mesh for ROW cars. Just being optimistic
If I recall correctly in Pete’s 991.2 Speedster thread he stated that Porsche indicated the mesh material for ROW cars was neccessary because of the independent throttle bodies specific to the speedster motor, as the ITBs and Particulate filters/backpressure mesh were directly related.
I highly doubt that the GT4 will be getting ITBs, so in that case technically there would also be no need for the mesh for ROW cars. Just being optimistic
05-19-2019, 12:18 PM
#6915