718 GT4RS
11-19-2021, 09:43 AM
#4306
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11-19-2021, 10:14 AM
#4307
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delete
Last edited by Sean in Texas; 11-19-2021 at 10:15 AM.
11-19-2021, 10:18 AM
#4308
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In one of those reveal videos with AP, he did mention THE throttle body (def not plural). I wondered if he misspoke or if that little bit of greatness didn’t make it over.
The air definitely warms up on the way in, moving or not. That engine is putting off heat which will warm the intake, and thus the air passing through it.
The air definitely warms up on the way in, moving or not. That engine is putting off heat which will warm the intake, and thus the air passing through it.
Last edited by Adrift; 11-19-2021 at 10:22 AM.
11-19-2021, 10:18 AM
#4309
11-19-2021, 10:34 AM
#4310
They already have an allocation??
11-19-2021, 10:37 AM
#4311
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In one of those reveal videos with AP, he did mention THE throttle body (def not plural). I wondered if he misspoke or if that little bit of greatness didn’t make it over.
The air definitely warms up on the way in, moving or not. That engine is putting off heat which will warm the intake, and thus the air passing through it.
The air definitely warms up on the way in, moving or not. That engine is putting off heat which will warm the intake, and thus the air passing through it.
11-19-2021, 10:45 AM
#4312
Rennlist Member
Thanks, Grant.
What is the current leading suspect for the missing 9 HP? Increased backpressure due to longer exhaust route? ECU detune?
What is the current leading suspect for the missing 9 HP? Increased backpressure due to longer exhaust route? ECU detune?
11-19-2021, 10:52 AM
#4313
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porscheflat6 (11-19-2021)
11-19-2021, 10:54 AM
#4314
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That was my guess (easy to recapture with a flash?), but AP did explicitly describe the rear-engined format exhaust having less back pressure, due to being shorter. Dunno. Maybe a smidgen of both.
11-19-2021, 11:00 AM
#4315
There it is. I can barely see the individual TB shafts and one blade just outside of the cylinder head port in that image. I hope they do some cutaway renders of the car obviously! 
11-19-2021, 11:06 AM
#4316
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11-19-2021, 11:13 AM
#4317
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What is the reason the 992 GT3 lost 10 PS from the previous RS?
11-19-2021, 11:29 AM
#4318
I’ve done a fair amount of playing with different intake and exhaust configurations, including with this intake system (991.2 GT dual flap plenum and runners).
AP has also said that actually 500ps is just the rated figure, conservative … he would expect it’s a little more in real life…. That’s from the auto bild video
Last edited by TDT; 11-19-2021 at 11:32 AM.
11-19-2021, 11:42 AM
#4319
Wow! Great find!! VERY interesting on the intake side.
Despite the revolutionary window vent intakes, the intake manifold is still the same basic design as a regular 4.0 GT4/GTS. The intake manifold features a huge collector that lives directly above the engine. This arrangement is less than ideal for power as intake air will tend to dwell there in that big box getting hot. I guess it is slightly better than the 4.0 GT4/GTS intake as the GT4RS intake manifold is plastic, and the 4.0 GT4/GTS intake manifold is metal, which would retain more heat. Then even more surprising - the GT4RS still has the relatively short intake runners off of the collector box to each cylinder, just like the 4.0 GT4/GTS has. The short intake runners can be better for torque, but they give up top end power.
I'm surprised how similar the design of the intake manifold is on the GT4RS vs the 4.0 GT4/GTS. And I think in both cases, Porsche left some power on the table with this intake manifold design.
Despite the revolutionary window vent intakes, the intake manifold is still the same basic design as a regular 4.0 GT4/GTS. The intake manifold features a huge collector that lives directly above the engine. This arrangement is less than ideal for power as intake air will tend to dwell there in that big box getting hot. I guess it is slightly better than the 4.0 GT4/GTS intake as the GT4RS intake manifold is plastic, and the 4.0 GT4/GTS intake manifold is metal, which would retain more heat. Then even more surprising - the GT4RS still has the relatively short intake runners off of the collector box to each cylinder, just like the 4.0 GT4/GTS has. The short intake runners can be better for torque, but they give up top end power.
I'm surprised how similar the design of the intake manifold is on the GT4RS vs the 4.0 GT4/GTS. And I think in both cases, Porsche left some power on the table with this intake manifold design.
Will be very interesting to see what the like of Dundon will do in this space… their work on their 992 GT3 will be directly relatable.
Last edited by TDT; 11-19-2021 at 12:07 PM.
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Daniels34 (04-17-2022)
11-19-2021, 12:07 PM
#4320
Here is a video about intake manifold design. It seems like Porsche is using these ITV more for overall intake design (economy, emissions, drivability) than just horsepower and throttle response like older cars (BMW) may have.
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Adrift (11-19-2021)