I was really impressed to see that the new Challenger Demon uses the Air Conditioning to make the intercooler more effective. Such a brilliant idea! Use what you already have instead of trying to REinvent the wheel..
We know that cooler air is packed with more oxygen. Why not figure a way to use the A/C on naturally aspirated cars?
I run an open element air cleaner on my car like many people do. This means it is breathing in air up to 140 degrees on a hot summer day. What would the gains be if the inlet air temperature were half of that? The A/C in my 2007 Ram recorded a temp of 49 degrees at the outlet. Aftermarket A/C for classic cars are even colder than that. What if you could somehow run a duct to the air cleaner to pipe in cold air?
I just thought about this on the way home from work and wondered if anyone else considered it. In a way, it could be a cheap way to add power with no drawbacks, right?

I would be curious to see what modifications were done to the HVAC system to get that done. It takes a ton of capacity to cool that much air at those kinds of RPMs. I am not sure the benefits are worth the effort on a n/a application, just getting a nice ambient air charge will get you at least 40°+ reduction in IAT on a hot summer day.

I first saw using the AC like that on an early 2000s SVT Lightning pickup and wondered the same things you are.

I had previously tried sucking my 1995 AC evap drain water into my Magnum 5.9 V8 with a second PCV valve and found it eliminated WOT pinging on 85 AKI fuel when the air temperature was above 90 degrees and the humidity was low.

Now that 80% open throttle “loophole” protected by Rep John Dingle is gone and engines have to stay at 14.7 air/fuel at max output
there certainly is potential with that mod because the hp consumed by AC at high rpm is modest, and gains from advanced timing and denser air probably exceed it, especially if boost is involved.

Don't forget that the underhood temp is way higher than the outside ambient temps. Factor in heat off the radiator, coolers, engine, exhaust etc and the existing filter is sucking all that in. One of the reasons I'm going NASCAR style on mine and ducting it to the cowl. Pretty much any newer, at least since early 90's, vehicle is pulling air in through ducting that grabs outside cooler air. You are very correct in that we can learn technology from newer rides and apply that to our old stuff.

On a naturally aspirated engine The drawback would be that you are sucking air through a condensor, so, it would be like running with a plugged air filter.

It would do more harm than good.

I don't believe it uses it under power, I think it is utilized off power to cool the liquid for the intercooler.


You would be better off sourcing a fresh air source, if you did manage to do something with the AC you would have to overcome the loss of running the compressor (10-15HP?) before you gained a thing.

C'mon Frankie...


Get that s!!t out there where it can breathe...

I think you're right. There's no free energy so any extra energy provided by cooling the inlet charge by the a/c compressor would be made back up by an extra load placed on the a/c compressor. My understanding is the a/c intercooling systems are designed to cool the liquid in an air to water intercooler between runs down the track when extra load on the a/c compressor doesn't matter. If you look at how many BTU/H an a/c system can cool, I think this is the only realistic application for this system. On a n/a maybe you could use it to cool fuel? Fresh air intake to the carb and sealing off it from outside air should be your first step IMO.

Heres a video that helps explain whats going on.

https://youtu.be/wLOkr-hUnU4

And for those that like to read...

In order to make sure the Demon's intake receives air cool enough to make 840 supercharged horsepower, Dodge used the car's air-conditioning system to chill intake temps. How do they do it? It actually pretty simple.

Instead of merely relying on the Demon's intercooler alone to cool air as it's pushed through the supercharger, Dodge engineers developed a passageway for the air-conditioning system to pass into the intercooler's closed loop, chilling the liquid coolant even further. This allows for cooler air temps, and therefore, more power.

The only downside? The A/C won't pump cool air into the cabin if you set it to cool the engine. We think that's a fair trade-off for a sub 10-second quarter-mile time.