I would think that would be hard to see through...

 

It's a good way to shave off those last tenths.

 

For DE, I don't think it matters as it isn't racing. I have been with many students who run with it on during hot days and I dig it. I have also heard that on the 911 Turbos (996/997) it actually helps to cool the Turbos as the AC lines run by the turbos. Again, it was something I heard in passing. I actually think it was you Dave who said that!

 

It all depends on how much amount of actual oil cooling capacity the car has., for DE is ok, I guess.

 

Sure, blame it on me. I can't say I've heard that before. When my TT hits the track I do leave the AC on.

 

They (e.g. Connie) frequently mention it in the HST (High Speed Touring) drivers' briefing - I guess they don't hold the COMMA and Club racers to the same requirement. I concur that it probably makes very little difference with regard to the track conditions.

 

Here we drive in 95 deg+ weather and 90+ RH... you can imagine the temptation to turn on the A/C for DEs... While I can't comment on performance loss, the A/C certainly exacerbates engine overheating esp. among the less "adapted" Italian cars. You're easily looking at 2 fewer laps in a 8-10 lap session before coolant/oil temps go "red"...

 

The A/C will do two things. 1) sap engine power which most modern Porsche have plenty of so no big deal. 2) Heat the air coming to the radiator due the condenser generating heat. For older cars this can cause the car to overheat or run warmer.