AC horsepower leach

[The Producer]

Hello,
I've been driving the entire summer with no air conditioning.
I've just fixed it and had it recharged. I drove home from the mechanics and noticed that my car wasn't as "zippy" as before.
How much horsepower does the AC compressor leach?

http://www.cb7tuner.com/vbb/showthread.php?t=180940

[JoshM]

We dynoed a 2009 Jetta TDI and it lost about 10% of hp and 6% of ft/lbs with the A/C on. Yours won't be the exact same, but it gives you an idea.

[The Producer]

We dynoed a 2009 Jetta TDI and it lost about 10% of hp and 6% of ft/lbs with the A/C on. Yours won't be the exact same, but it gives you an idea.

Last year I had AC, but I don't remember the MPGs. Do you still have yours(AC)?

[JoshM]

Last year I had AC, but I don't remember the MPGs. Do you still have yours(AC)?

Yes, my new CB has A/C. I haven't checked MPG on it though.

On my first CB, an EX, my MPGs only went down 1-2mpg with A/C on. Definitely not enough difference to make me feel like baking in the heat.

[PR CB7]

a/c is a load on the engine, it does not affect peak horsepower, being that the ecu, cuts the signal to the a/c relay once it sees WOT

so, on a dyno if your car put out 115whp, it should still be 115whp with the a/c on
whats going to be different is the curve, both hp and tq

[JoshM]

a/c is a load on the engine, it does not affect peak horsepower, being that the ecu, cuts the signal to the a/c relay once it sees WOT

so, on a dyno if your car put out 115whp, it should still be 115whp with the a/c on
whats going to be different is the curve, both hp and tq

Must not be the case on an '09 TDI.

91whp w/ A/C.
102whp w/o A/C.

Both runs were last Friday and nothing changed except for 3 minutes in between runs.

We then ran no A/C and yes A/C several times there after and results were similar time after time.

[The Producer]

a/c is a load on the engine, it does not affect peak horsepower, being that the ecu, cuts the signal to the a/c relay once it sees WOT

so, on a dyno if your car put out 115whp, it should still be 115whp with the a/c on
whats going to be different is the curve, both hp and tq

But the engine can only make a max of 115 horsepower.
If I put a load of 17 horsepower (guessing ac drain), then the engine doesn't magically get 17 more horsepower. It becomes a 95 civic dx (98 horsepower)

[PR CB7]

this is on a 09 jetta tdi that its rev limiter is 4.5k rpms
there are a lot of compressors these days that spin this fast, so on this car might be different, the compressor might not disengage being that its max speed will be 4.5k

on a gas powered or a car that can pass 5.5k the compressor will turn off when WOT is applied, anything less from WOT the compressor will stay on

to try this, simply pop the hood, and have somebody WOT the car while you look at the CC, i can assure you it will disengage

[mtnbikaah]

turn off the A/C when you need "oomph." And turn it back on when you don't

i wish my a/c working in my wagon. I'm too lazy/cheap to fix it.

[Rahhstah]

Doesn't everyone refer to the A/C switch as the Turbo Engage switch when ac is off...

I don't notice a difference in my 91 or 96 DXs when the AC is on or off....other than I start to cook.

[The Producer]

to try this, simply pop the hood, and have somebody WOT the car while you look at the CC, i can assure you it will disengage

CC = Cruise control?

I'm assuming you mean compressor.
If that's the case, how will I tell if it kicks on?

turn off the A/C when you need "oomph." And turn it back on when you don't

i wish my a/c working in my wagon. I'm too lazy/cheap to fix it.

I've thought about doing it in recent days.
I've held off though, because my car has started to downshift and rev higher. I think it has something to do with the heat. I'm not complaining. I'm getting better MPGs and I'm faster than other cars!

[Xclusive1]

I just recharged the a/c on my cb and noticed the same thing, now when I get on the freeway I feel like it lags a bit so I turn it off before I jump on then turn it back on once I'm in at a steady speed.

[cloudasc]

I don't believe our cb's turn off the ac when we WOT, as long as the switch is on, the compressor clutch is engaged.

Newer cars like my Fit, cycle the a/c on/off all the time in order to help with fuel economy, it also disenages when going WOT. I'm happy with it cycling on and off while cruising, but I kinda wish it didn't when I come to a stop light.

[JBradley500]

Everyone knows having the windows down hurts performance also. Drag on the car increases dramatically as speed increases. I think at typical driving speeds its something like doubling your speed will increase your drag 4 times. So basically you're better off with the AC on at cruising speeds for optimal efficiency. Driving through town is better with the windows down. My 2 cents.

[Chris2388]

When I have my A/c on in my 92 LX it seems like after 15 mins my car starts to act like my clucth is slipping. I will see and hear my rpms rise but my speed will stay the same. I then have to turn it off and after about 5 mins my cars drive fine.... has this happend to anyone else?