new to stick

[bobbyn]

hi all,

just last week i upgraded from an '02 p5 auto to an '07 mazda3 5-door manual (2.3L in sunlight silver)! i think the car's superb, and have been having fun with it so far.

i went with a manual tranny because i wanted to learn something new, and that's been going well, but today i noticed that when running the air conditioner the engine feels sluggish and i even managed to stall it for the first time at a drive up window.

is this normal? with the a/c on do you generally have to be more aggressive with the gas pedal to prevent stalling? i hadn't tried driving with the a/c on until today.

ty,
bobby

[flipstylex]

yeazer...watch out on hills, if u dont give enough gas, the car goes on reverse !!!

[clicknext]

Yes, you get less power with the A/C on with an auto as well. It takes a lot of power away from everything else.

Pretty good that that would only be the first time you've stalled. Though I guess with that much power it's a lot harder to stall.

[bobbyn]

i used to ride a motorcycle, so conceptually i've got it all down. :)

[Abaddon]

Interesting that you bring this up.. the other day I was actually looking at the calculations for how much power the A/C system drains from a car.

After looking at various numbers for standard system, I ended up concluding that the A/C unit running at full blast would consume about 13.5hp.

Thinking about it for a while, I also realized that the actual TORQUE that would be consumed by the system varies inversely with engine speed. So, although the A/C only needs 13.5hp.. it ends up having a much more profound effect at low engine speeds.

This is why it effects you so much at low rpm, and thus why you stalled the car.