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Bettchen
23-09-2015, 17:55
Does the air temperature affect engine power? The hotter it gets the less power a car has?
Are naturally aspirated cars more sensitve to air temperature than turbo charged ones? What's about the height of a track, do cars have more hp at sea level than on a track which is 500m high?

Umer Ahmad
23-09-2015, 17:57
Temperature i dont think matters.

Elevation: yes

Vennt
23-09-2015, 17:57
Yes to air pressure & elevation, barometric pressure is modelled to have an effect, which differs between NA and Turbos.

Umer Ahmad
23-09-2015, 18:00
http://en.pcars.shoutwiki.com/wiki/Physics#My_MP12c-GT3_seems_to_be_underperforming_at_this_track.21.3F

Jussi Viljami Karjalainen
23-09-2015, 18:06
Does the air temperature affect engine power? The hotter it gets the less power a car has?
Are naturally aspirated cars more sensitve to air temperature than turbo charged ones? What's about the height of a track, do cars have more hp at sea level than on a track which is 500m high?Indeed not 100% sure about temperature, but on the elevation side:

Turbo cars are by nature nearly immune to this effect, since the turbo will keep the pressure up anyway, so yes, it affects NA cars more than turbos. And it's not only something that varies from track to track, it's fully dynamic and actively changes while you're on the track. For example on Nordschleife, where the S/F line is at almost 620 meters meters and Breitscheid is at around 318 meters (so a roughly 300 meter gap), you can very clearly notice that the power output of NA cars varies significantly between the high and low areas of the track. =)

joelsantos24
23-09-2015, 18:10
The elevation affects the engine performance, in specific the internal combustion engines with atmospheric induction. The higher the altitude, the lower the air pressure, so the engines' torque will decrease as the car "climbs", according to the proportion of air in the atmosphere. I read somewhere, that Pikes Peak cars, starting the race at approximately 2.74 km above sea-level, will display around 71% of the sea-level torque, corresponding to the 71% air pressure at that altitude.

Hlspwn
23-09-2015, 18:29
No idea about the game, but IRL the air temperature can affect a turbo car especially with no intercooler. I have experienced on very warm days the car bogging down on initial acceleration due to sucking in hot air from the engine bay. As speed increases and air gets forced into the car this lagging feeling goes. Put the car in the same scenario at night no bogging down.
Turbo cars I have owned have always felt the most powerful when the air is cold and dense, but that's when you struggle to put the power to the road :(

Jussi Viljami Karjalainen
23-09-2015, 18:41
The elevation affects the engine performance, in specific the internal combustion engines with atmospheric induction. The higher the altitude, the lower the air pressure, so the engines' torque will decrease as the car "climbs", according to the proportion of air in the atmosphere. I read somewhere, that Pikes Peak cars, starting the race at approximately 2.74 km above sea-level, will display around 71% of the sea-level torque, corresponding to the 71% air pressure at that altitude.Thanks for sharing. =)

The last time I compared a low lying track (Dubai) to a high altitude one (Nürburgring) I got a difference of roughly 9% on average between them with the NA GT3 cars, or between 40-50 bhp or so. It varies somewhat by car, for example the already tightly restricted and starved for air M3 GT (29.8 mm restrictor) only had 89.8% of the low altitude power left at high altitude, whereas the R8 LMS (47.0 mm restrictor) had 91.8% left. It can definitely be a consideration if running in a series that focuses mostly on low or high altitude tracks for example.

joelsantos24
23-09-2015, 19:32
Thanks for sharing. =)

The last time I compared a low lying track (Dubai) to a high altitude one (Nürburgring) I got a difference of roughly 9% on average between them with the NA GT3 cars, or between 40-50 bhp or so. It varies somewhat by car, for example the already tightly restricted and starved for air M3 GT (29.8 mm restrictor) only had 89.8% of the low altitude power left at high altitude, whereas the R8 LMS (47.0 mm restrictor) had 91.8% left. It can definitely be a consideration if running in a series that focuses mostly on low or high altitude tracks for example.
No problem. :cool:

Air starvation! That's exactly the key point, when talking about how altitude affects engine performance. Good point.

Moreover, it's amazing how accurate the Project CARS' model is, to reproduce these (and so many other) variables. That's a huge credit to SMS.

Jussi Viljami Karjalainen
23-09-2015, 19:39
No problem. :cool:

Air starvation! That's exactly the key point, when talking about how altitude affects engine performance. Good point.

Moreover, it's amazing how accurate the Project CARS' model is, to reproduce these (and so many other) variables. That's a huge credit to SMS.Hehe, indeed. Car engines are really just glorified air pumps after all. :D

hkraft300
24-09-2015, 06:42
Ruf GT3 is hurt by pressure even at Bathurst. Drive with the telemetry screen up you can see the NA cars power levels change depending on elevation.
As for turbo cars being affected by temp - may depend on how the car is tuned. Maybe you wouldn't notice a huge difference in the 12C GT3 (detuned for BoP), of the unwillingness during a hot summer day taking off at the lights. Doubt you'd also notice it racing because you're on full throttle or high revs a lot. Oil, water and tire temp is definitely affected by temperature; oil temps affected more in forced induction cars than NA.
Having to take these things into consideration (and being able to use to my advantage) is fantastic.