Before I ask the question, let me tell you what I think the answer is:

B. Won't work, because drain on engine would outweigh gains from cold air.


Personally, I don't notice any loss of power in my '03 MCS when using the AC. I know some MC owners have posted to the contrary. But it got me thinking.

What if you could run a duct from your AC directly into your air box? Would the result be more horsepower, less horsepower or would the compressor drain and the colder air fight to a draw? Would the air not be cold enough to make a difference? Would packing a bag of ice in your airbox before an autocross run add horsepower?

I guess if it worked, someone would have mentioned it by now. Seems like it would work for sure if the AC compressor was electric, like the power steering pump.

I plan on getting my car dynoned soon and was going to do a run with the AC on to see what the power difference is.

Let the "You're a dumb@$$" comments begin!

 

Don't know about the AC but I have seen icebags on intercoolers befor auto-X's

 

Saw icebags on WRX intercoolers at a dyno day as well. And I heard mention about putting a sliver of dry ice in the MCS scoop...

 

Well if it worked for Pons and Fleischmann what are you worried about? Physics was never my strongest subject, but isn't this illegal? Something about violating the Conservation of Energy act, or summat? In Oregon we're not allowed to take out more energy than is put into a system. Things may be different in Virginia.

 

How much power does the A/C draw at full-clip? 15 whp? (that's a complete guesstimate). If you could lower the intake air temp from, say 140 F to 115F, you could see a power gain of about 5whp. You'd have to consider the airflow from the A/C as well. I have seen applications (GMC Syclone/Typhoon) where the water in their water/air intercooler was chilled on demand by the A/C. The nice thing about that is you could chill the water with the A/C while waiting in line at the dragstrip. Then, when it is your time to run, turn off the A/C (losing the engine load from it) and enjoy the advantages of colder-than-atmospheric intake air.

 

No, I said "ice" not "margarine." Just kidding. Had to look up your reference, I admit. I take it your opinion is that if the AC thing works, it would be the equivalent of say, a perpetual motion machine. If I came up with one of those, I'd have to try it out -- legal or not!

 

Thanks Andy. Had no idea the idea was already in use. I shall investigate further!

 

Check out the writeups of the Ford Lightning concept truck from this year's auto shows. It was purported to use an A/C-chilled water/air intercooler as well.

 

Doubt it. But simple water injection does make a difference. You can find kits of varying degrees on ebay and elsewhere...

Here's a start:
Try our AMSOIL 0W30. Lower the engine temps under load and keep your oil pressure where it needs to be. One less worry and under higher loads the 0W30 will withstand the sheer the stock oil won't..

 

>>Doubt it. But simple water injection does make a difference. You can find kits of varying degrees on ebay and elsewhere...
>>

...and it obeys the Laws of Energy Conservation. You don't want the Bureau of Energy Conservation agents after you! Worse than those Matrix dudes, you betcha.

 

Aye. How the Lightning system works is it builds up a charge when you dont care and uses it when you do. Think "im riding down the highway, I might as well fill up my supercool supercooler" and it will charge up a holding tank. When you hit WOT, it allows this tank of compressed goodness to expand and thus cool your intake charge. Its a form of stored (or Potential) energy.

It can't/doesn't work simultaneously because of the afformentioned conservation of energy.


--
Cheese

 

>>>>Doubt it. But simple water injection does make a difference. You can find kits of varying degrees on ebay and elsewhere...
>>>>
>>
>>...and it obeys the Laws of Energy Conservation. You don't want the Bureau of Energy Conservation agents after you! Worse than those Matrix dudes, you betcha.
>>


I like the "you betcha"... caught me off guard.

Along the same thread of thought, a friend of mine who used to race years ago told me how they would form copper fuel lines into a coil inside of a large coffee can, fill the can with ice or dry ice to lower the temp of the fuel/air in the carb. I suppose every little bit helps but man that seems to be taking it a bit far.

Jim

 

Compressor from the AC draws to much power to give you any advantage. Look at threads about “Bad power with AC on”. My cars have always had better performance with the AC off than using it and you would be defeating the purpose. To draw the cold air from the AC in, only to loose the power the AC needs to operate. IMO.

 

>>Compressor from the AC draws to much power to give you any advantage. Look at threads about “Bad power with AC on”. My cars have always had better performance with the AC off than using it and you would be defeating the purpose. To draw the cold air from the AC in, only to loose the power the AC needs to operate. IMO.

Besides, air output from the A/C isn't exactly 0°C

If it's 120°F outside, you would feel the change, but really.. it's not 120° for most people and still the work to make it happen seems unworthy to me.

 

The short answer is that yes, this could work, and in fact does work, but there's still no such thing as a free lunch. As macncheese said, you can use the airco to "store up" some coldness(tm) for use later. The airco automatically turns off when you floor it. No laws are broken. The downsides include:

- While chilling down the storage unit, (an insulated tank of antifreeze?) you are harming your gas mileage, or hurting your performance, or both.

- The storage system adds weight to the car.

- You can only store enough coldness to "boost" for something on the order of 30 seconds. (I believe that's how the GM system works.) Then you have to back off and let your coldness build up again.

This is just roundabout way to store energy. What's cool (heh) about it is that the "stored energy" is in a very non-dangerous form. Plus, it uses many components that are likely already on the car. Other ways to do energy storage are:

- Batteries or capacitors, and an electric motor. "Hybrid" cars use this method to boost the apparent power of their tiny gas powerplants. Downside: Heavy. Upside: You can use regenerative braking.

- Compressed air. I forget how this one works exactly, but I think it was GM again that is showing off a system. You use a compressor to store air at some ridiculous pressure, then you use said pressure to generate a ton of torque for a few seconds. I got the impression that the Suburban(?) that they were testing got something on the order of 100 ft/lbs of extra oomf off the line, maybe more.

Oh, and yes an airconditioner could easily chill a fluid down to 0C or lower. All you need is time and energy.

-Dave

 

OK- I thought about this topic as well in the last week-
I got the same idea to route AC cold air to intake box.
I see that if the AC is on you loose power to it
But you gain some HP by having a real cold intake running.

Well what about leaving the AC off. No draining of power.
Run a hose from the intake box out to a fresh air source maybe on the side of the fender or higher up on the bonnet near the driver for cold air and
Add a hose to the passenger compartment where you can add (by hand?)
A coolant like sprayed Liquid nitrogen. I would have to be controlled somehow- could use a lever . I use a medical LN2 spray at work that acts like a blast of AC but is is costly and only chills the air for about 4 feet- It is very cold though on the order of less than O degrees depending on how much other air is around. If you spray it into a hose and chill the air then it could work. You would not be spraying the LN2 onto the intake box directly merely providing a source of colder than usual air to help without using the AC to do it.. Maybe a foot or knee control to handle the LN2 spray hooked up to a hose. Could get about 20 minutes of spray out of one thermos like container. It is not flamable and I think since the intake is getting a mix of fresh air and LN2 it is not bad for the engine- just making for a cold intake.

 

MINIHUNE,
Your idea is essientially an intercooler chiller. I think both the big nitrous companies have kits available. I've seen a few DIY systems using gas BBQ grill burners and a CO2 tank.

 

Answer #1: I can't imagine the A/C idea would flow enough, or cool enough to be more accurate, to outweigh the benefits.

Answer #2: Off the top of my head I don't think you're violating the 2nd law of thermodynamics, because you're neglecting the energy that's converted to heat (and subsequently cooled by the A/C's radiator.)

In fact, when you think about it, doesn't the S/C operate the same way? (draw energy from crank to put more energy back in system)?

hmmmmm.

Jeff

 

Umm...I'll take "conservation of energy" for $200, Alex.

"What is energy in equals energy out?"

 

Thanks for all the comments. I will post the results of the dyno testing asap. If for no other reason than to let everyone know how much power the AC drains on a modded MCS. Jeff, that's a good point you make about the SC. I mean, it uses HP to make HP. So it's not inconceivable that the AC could do the same. It's not a free lunch, because they both cause the car to use more gas, right? I agree that just pumping cold air into the airbox before a run would probably make more sense -- but still yield only minimal results. Still fun to think about, though. JR