Hi guys,
Im not sure what forum to post this question in. And sorry if its a noob question or sounds retarded. However, I was just wondering.
When we use our AC it takes power out of the car. I was wondering if a bigger intercooler would nullify this effect since it can cool more air. I was wondering this because I know summer is coming up and I know colder air is more efficient. Thanks all for help.

 

No, it won't.

 

I never really heard any hard evidence about AC stealing HP

 

the car loses power because when you have the a/c turned on the a/c compressor is engaged and causing more parasitic power loss. it's not directly related to temperature. you're probably looking at 1 - 5 hp loss. not a big deal.

 

Really!? Well go out to your car and do a couple pulls with the AC on and then without....

 

Just to elaborate on what Greg K said, the only part of your a/c that consumes considerable power is the compressor. Depending on your a/c settings, the compressor will come on and off periodically. You can hear it clicking on and off, in fact.

The pulley that drives the compressor is on a clutch, so while it spins all the time, it only drives the compressor some of the time. Only when it is driving the compressor is it actually draining any power from the engine.

Now as for the intercooler, there's a number of factors that you have to be aware of. It's a balance between pressure drop across the intercooler, temperature drop and transient response.

The pressure drop will directly affect your boost. Now we all know that more boost = more power. The drop in temp will also increase power, but we're talking about 1% for every 11degF drop or something like that. Small, basically. So you can be cooling more, but if the intercooler causes a large pressure drop in doing so, then you're probably going to lose power. Finally, there's the transient. If there's a lot of volume in the i/c, then it's going to take some time, once you put your foot down, for all/some of that air to accelerate and start rushing towards to intake manifold.

Now both the intercooler and the a/c works best when the car is in motion and worse when it's stationary. IMO I don't think that specially at standstill a larger i/c is going to do that much. Then again, we've already established that the a/c isn't using all that much power anyway.

If you're worried about the a/c sapping power, set the temp or thermostat a little higher.

 

At WOT the a/c compressor should kick off, therefore not robbing your car of any power.


The larger i/c has only proved to be useful after a turbo upgrade.

 

Oh I see. Now I understand. I always thought the AC sapped power cause of temperature or cooling. But after that explanation it makes more sense. Thanks for help.