How does running A/C effect performance???
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: How does running A/C effect performance??? (scorp508)
Scorp: Thanks for the reference - I'm looking for some old graphs I have laying around somewhere that I captured on my Auto Xray. Hopefully, one is full throttle so I can compare TPS to the A/C request.
LT-4 - I've always heard that you give up no more than 2 to 3 hp to the compressor with a mileage penalty of 1 to 2 mpg (seems like a lot considering the HP involved doesn't it?). I know that the one time my kids talked me into running at Pomona, I tried it with a/c on & off. Times were pretty much (embarassingly so) the same.
LT-4 - I've always heard that you give up no more than 2 to 3 hp to the compressor with a mileage penalty of 1 to 2 mpg (seems like a lot considering the HP involved doesn't it?). I know that the one time my kids talked me into running at Pomona, I tried it with a/c on & off. Times were pretty much (embarassingly so) the same.
Le Mans Master
Joined: Oct 2002
Posts: 7,178
Likes: 1
From: Bahston Mass.
Re: How does running A/C effect performance??? (LT4BUD)
I think I remember Mojo saying that he ran with his AC on, and got some pretty good times.
I notice a major difference when I kill my A/C on the street.. Then again, I think my freon must be low, because my A/C is cycling a lot more then it should be.....
I notice a major difference when I kill my A/C on the street.. Then again, I think my freon must be low, because my A/C is cycling a lot more then it should be.....
Thread Starter
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Re: How does running A/C effect performance??? (Jbaker)
Well if the A/C disengages immediately upon full throttle, then there should be minimal if any effect on performance, so Mojo's experience would have verified this. If there is a significant delay in the A/C dropping out then there could be a measurable effect. You guys have introduced another situation which is responsiveness at say 3/4 throttle. Wonder how many TPS are slightly out of adjustment.
I think there must be more than 1-2hp loss if the A/C is on. On my daily driver, a 91 Toyota pu, the A/C stays on at full throttle & the loss in performance is more than noticeable.
BTW Scorp, on a recent situation I had the air on and windows down on a hot muggy evening. Interesting you mentioned windows as that was also on my mind whether that made a measurable drag or not. Fortunately for what it worth the LT4 was strong enough to make up for my errors!!
I think there must be more than 1-2hp loss if the A/C is on. On my daily driver, a 91 Toyota pu, the A/C stays on at full throttle & the loss in performance is more than noticeable.
BTW Scorp, on a recent situation I had the air on and windows down on a hot muggy evening. Interesting you mentioned windows as that was also on my mind whether that made a measurable drag or not. Fortunately for what it worth the LT4 was strong enough to make up for my errors!!
