GT4 Aero Adjustment
#16
+981 My car felt a bit lite going 125-130mph in a long straight with a slight right at Spring Mountain. Definitely doing these aero adjustments.
#17
Drifting
So it seems the answer is that it depends on what the car is doing under your driving style and any other setup changes you've made. The sweet spot is at some happy medium whose location depends on many other variables, but reducing understeer and increasing front grip are not always the same thing.
Last edited by jphughan; 10-03-2015 at 12:28 AM.
#18
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#19
What are the sway bars set at from the factory?
#21
#23
Burning Brakes
I'm pretty sure somebody posted a link to Auto Motor und Sport with CD and downforce figures from testing, but I can't remember which thread. Anybody?
#24
Rennlist Member
Exactly what JPhugan posted. AP said it was a regulatory issue having to see brake lights at certain angles. He also said that otherwise it would be no problem to have car at full aero because at highway speeds aero has little effect.
#25
Burning Brakes
#27
Which is more than the GT3!
https://rennlist.com/forums/997-gt2-...r-997-1-a.html
Sport-Auto tests basic lift/drag in the Mercedes wind tunnel at 200km/h.
991TurboS Front 20Kg, Rear 40Kg
991GT3 Front 18Kg, Rear 29Kg, 0.33Cd
991S Virtually none, Cd 0.29
GT3RS4.0 Front 14Kg, Rear: 58Kg on highest setting, 0.35Cd
GT3RS.2 Front: 11Kg, Rear: 49Kg on lowest setting, 0.33Cd (On high setting it's same as 4.0)
GT3.2 Front: 15Kg, Rear: 19Kg on lowest setting, 0.32Cd
GT2RS Front 14Kg, Rear 35Kg
GT2.1 Front 9Kg, Rear 29Kg
GT3RS.1 Front: -2Kg, Rear 10Kg, 0.3Cd
GT3.1 Front ~0, Rear ~0 (they said it was virtually non existent, but not buoyant.), 0.29Cd
996GT3RS Front -19Kg, Rear 25Kg
BMW M3GTS Front 7Kg, Rear 30Kg, 0.32Cd
https://rennlist.com/forums/997-gt2-...r-997-1-a.html
Sport-Auto tests basic lift/drag in the Mercedes wind tunnel at 200km/h.
991TurboS Front 20Kg, Rear 40Kg
991GT3 Front 18Kg, Rear 29Kg, 0.33Cd
991S Virtually none, Cd 0.29
GT3RS4.0 Front 14Kg, Rear: 58Kg on highest setting, 0.35Cd
GT3RS.2 Front: 11Kg, Rear: 49Kg on lowest setting, 0.33Cd (On high setting it's same as 4.0)
GT3.2 Front: 15Kg, Rear: 19Kg on lowest setting, 0.32Cd
GT2RS Front 14Kg, Rear 35Kg
GT2.1 Front 9Kg, Rear 29Kg
GT3RS.1 Front: -2Kg, Rear 10Kg, 0.3Cd
GT3.1 Front ~0, Rear ~0 (they said it was virtually non existent, but not buoyant.), 0.29Cd
996GT3RS Front -19Kg, Rear 25Kg
BMW M3GTS Front 7Kg, Rear 30Kg, 0.32Cd
Last edited by ShakeNBake; 10-03-2015 at 02:49 PM.
#28
Those Sport Auto downforce numbers are for a PCCB equipped car. In the text they note that iron rotor cars make significantly more front downforce: 5 kg more with the inserts, 7 kg more without. So a standard brake car in high downforce config is probably running 19 kg front, 38 kg rear, 57 kg/ 125 lbs downforce total at 125 mph.
#29
I can confirm that on the GT4 without the front inserts removed and without the rear wing adjusted to the higher level the car felt light and loose on the high speed sweeper at Bahrain International Circuit. I will be trying the aero adjustments next friday
#30
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you might be better off running a taller gurney flap insert on the top/trailing edge of the rear wing as opposed to just increasing the rake. might want to try that as a single layer CF gurney flap would be pretty cheap.