911R's rear diffuser
10-12-2016, 06:30 AM
#61
Race Director
I don't understand how this vestigial diffuser has any meaningful effect at all on creating downforce. To do so it would need to accelerate air underneath and create a Venturi effect, this requires height and actual tunnels/channels... with a high exit at the end which can't exist on a rear engines car.. (unlike with a midengine car where the rear is unencumbered). These are little more than small appendages, with little depth to create channels and no height. Seems so much like a marketing gimmick to me... not much different from a zero angle of attack flat spoiler on the back of modified Japanese hatchbacks
10-12-2016, 12:42 PM
#62
Rennlist Member
installation looks easy. clearance is not an issue. But would like to know if it will lead to any imbalance on a GT3.
http://www.autoevolution.com/news/20...01.html#agal_8
look at above link and pic. The new GT3RS or GT2RS God knows what it is seems to have a similar diffuser as the 911R
thanks
http://www.autoevolution.com/news/20...01.html#agal_8
look at above link and pic. The new GT3RS or GT2RS God knows what it is seems to have a similar diffuser as the 911R
thanks
10-12-2016, 01:38 PM
#63
Three Wheelin'
I don't understand how this vestigial diffuser has any meaningful effect at all on creating downforce. To do so it would need to accelerate air underneath and create a Venturi effect, this requires height and actual tunnels/channels... with a high exit at the end which can't exist on a rear engines car.. (unlike with a midengine car where the rear is unencumbered). These are little more than small appendages, with little depth to create channels and no height. Seems so much like a marketing gimmick to me... not much different from a zero angle of attack flat spoiler on the back of modified Japanese hatchbacks
10-12-2016, 05:17 PM
#65
Drifting
I don't understand how this vestigial diffuser has any meaningful effect at all on creating downforce. To do so it would need to accelerate air underneath and create a Venturi effect, this requires height and actual tunnels/channels... with a high exit at the end which can't exist on a rear engines car.. (unlike with a midengine car where the rear is unencumbered). These are little more than small appendages, with little depth to create channels and no height. Seems so much like a marketing gimmick to me... not much different from a zero angle of attack flat spoiler on the back of modified Japanese hatchbacks
10-13-2016, 05:17 PM
#66
Nordschleife Master
Looks cool, sounds cool. It's called marketing at it's finest.
10-13-2016, 06:01 PM
#67
The following users liked this post:
frederickcook87 (10-08-2021)
10-22-2016, 01:58 PM
#70
Diffuser... 
Come on people! Buy and modify! That should be actually 4000EUR option from the factory. Porsche missed that one
I am looking forward for track reviews!
I could think of some vendors already offering this in carbon, slightly improved over the factory and except giving tons of downforce actually giving also thrust!
Come on people! Buy and modify! That should be actually 4000EUR option from the factory. Porsche missed that one
I am looking forward for track reviews!
I could think of some vendors already offering this in carbon, slightly improved over the factory and except giving tons of downforce actually giving also thrust!
10-22-2016, 06:40 PM
#71
Rennlist Member
I don't understand how this vestigial diffuser has any meaningful effect at all on creating downforce. To do so it would need to accelerate air underneath and create a Venturi effect, this requires height and actual tunnels/channels... with a high exit at the end which can't exist on a rear engines car.. (unlike with a midengine car where the rear is unencumbered). These are little more than small appendages, with little depth to create channels and no height. Seems so much like a marketing gimmick to me... not much different from a zero angle of attack flat spoiler on the back of modified Japanese hatchbacks
1. Just because it is a rear engine car doesn't mean from the low point (oil pan) to the high point (near back of headers/exhaust) it doesn't slop up. It's does, look closely
2. Just because you "can't feel it" doesn't mean it doesn't create downforce. Did you drive the exact same car without it? this is like when patients tell me the pain medication isn't working but they have 5/10 pain. Well, go without the meds and then tell me, because it may end up 10/10 pain.
3. Just because the car might feel "unstable" at high speeds doesn't mean it isn't working. It might be more unstable without it. What is your reference point, a GT3 RS? It isn't going to produce the same downforce as a huge wing and Porsche doesn't claim that it does.
Why is there so much skepticism, it isn't like Porsche is making this out of Asian carbon fiber and charging $10k for it.
The following users liked this post:
frederickcook87 (10-08-2021)
10-22-2016, 07:10 PM
#73
Rennlist Member
larger fins could add a bit more, but you don't want them larger to the point where it extends lower than the fins at the front or beginning of the diffuser as this adds no benefit and may only create clearance issues
10-22-2016, 07:11 PM
#74
Race Director
the material and the cost are irrelevant... to how much downforce is created. hardly worth addressing..
Pain is visceral, subjective, impossible to be measured objectively unless you think you can measure a VAS score to gauge pain across multiple subjects. (and we both know the answer to that one). Downforce is objectively and precisely measured.. your analogy is broken at the start line.
The issue is that the when form factor is not functional, then there this just an appendage which doesn't work for it's intended job.
since you understand aerodynamics 101.. check out how large the difference between the low point and highpoint of a diffuser has to be on a racecar to create any meaningful downforce.. and also how low the fins have to be to the ground to maintain the vacuum. maybe real world function isn't taught in 101 class.. that's just theory.
Last edited by CAlexio; 10-22-2016 at 07:42 PM.
10-22-2016, 08:04 PM
#75
Rennlist Member
the material and the cost are irrelevant... to how much downforce is created. hardly worth addressing..
Pain is visceral, subjective, impossible to be measured objectively unless you think you can measure a VAS score to gauge pain across multiple subjects. (and we both know the answer to that one). Downforce is objectively and precisely measured.. your analogy is broken at the start line.
The issue is that the when form factor is not functional, then there this just an appendage which doesn't work for it's intended job.
since you understand aerodynamics 101.. check out how large the difference between the low point and highpoint of a diffuser has to be on a racecar to create any meaningful downforce.. and also how low the fins have to be to the ground to maintain the vacuum. maybe real world function isn't taught in 101 class.. that's just theory.
Pain is visceral, subjective, impossible to be measured objectively unless you think you can measure a VAS score to gauge pain across multiple subjects. (and we both know the answer to that one). Downforce is objectively and precisely measured.. your analogy is broken at the start line.
The issue is that the when form factor is not functional, then there this just an appendage which doesn't work for it's intended job.
since you understand aerodynamics 101.. check out how large the difference between the low point and highpoint of a diffuser has to be on a racecar to create any meaningful downforce.. and also how low the fins have to be to the ground to maintain the vacuum. maybe real world function isn't taught in 101 class.. that's just theory.
Carry on