does a.c take away power?

[old skool]

I've tried to look up how an air conditioning unit works in road cars, but with no luck! I want to know why I can feel power loss and notice bad fuel economy levels when I run my type R civic.(slow or fast)

I've heard that a.c generally takes away up to 3 horsepower, Is this true or is it just psycological?

[avsfan733]

its true, its because of the effort that it takes the engine to turn the compressor. removing it and getting a shorter belt, or replacing the compressor with a blank pulley removes the drag that the compressor creates and gives you the power back. It may be more than 3 HP in some cases depending on the belt and pulley design, and the size of the compressor and other ariables like that

[shiny side up!]

It is probably sapping quite a bit more than 3hp... you probably wouldn't notice that small of a change in power output...

[AlexF]

about 5% on modern systems...

Alex

[scrooge]

2/4 mpg are typical figures tha have been used for years

its like loading an alternator with 3 sets of big spotlamps the engine has to push the extra drag/work harder to produce the same power!

[Cryos]

Just threw the Brain Bee ST6000 onto an Volkswagen Passat TDI and threw on the live readings @ 998RPM without an A/C on the altinator load is at the default normal 12% load, throw on the a/c and the load gose upto 18% load.

Best way to show this is look cloosly at your rev meter on the dash, then turn on the a/c you will see the gauge go down for a second (same as pressing all the electric window buttons down)...

In some motorsports they have a switch on the dash to turn off the altinator which gives something like an extra 5hp