How much of a drag is your AC? - PeachParts Mercedes-Benz Forum

muleears · #1 04-03-2007, 09:29 AM

I have started using the AC the last few days and it seems to put a significant drag on my 124 (Fritz) Almost as bad as before I adjusted my ALDA. Seems to be more of a strain than last year. The car needs considerably more pedal to accelerate. What are your experiences?

rrgrassi · #2 04-03-2007, 09:38 AM

The R4 on my w123 617.952 is the same way. Once I'm up to speed no problem, it's the getting up to speed that is. A/C off, no prob.

Marcb · #3 04-03-2007, 10:09 AM

Our 87 300D seems to have some drag with the AC engaged but not nearly as noticeable as you've mentioned. You can definitely feel it engage, however. I haven't noticed using any additional pedal to accelerate.

vahe · #4 04-03-2007, 10:16 AM

On my 240D 77, with that massive York unit, the drag was sufficient to let me use the A/C as emergency brake in mountain passes where I did not want to overheat my breaks.

Vahe
240D 77/350K

sailor15015 · #5 04-03-2007, 11:12 AM

I can tell that I need to give it a little more pedal when the a/c is on, and it might add a second or two to my 0-60 time. I can also feel it cycling as I'm cruising at 65 down the highway. The gf thinks I'm nuts because I ask her if she can feel it too (she can't). It definately is not a significant hindrance in performance, though.

kerry · #6 04-03-2007, 11:14 AM

Quote:

Originally Posted by vahe

On my 240D 77, with that massive York unit, the drag was sufficient to let me use the A/C as emergency brake in mountain passes where I did not want to overheat my breaks.

Vahe
240D 77/350K

LOL! Combination AC and retarder.

Hit Man X · #7 04-03-2007, 11:25 AM

Quote:

Originally Posted by vahe

On my 240D 77, with that massive York unit, the drag was sufficient to let me use the A/C as emergency brake in mountain passes where I did not want to overheat my breaks.

Vahe
240D 77/350K

My 280S has that GIANT York too!

DubMutant · #8 04-03-2007, 11:50 AM

Guess I dont need to be worried about it. The PO never repaied it on my car so there's no belt on the compressor!! I'll be using straight dry ice this summer, I just hope I can see out the windows.
Ben

pawoSD · #9 04-03-2007, 11:57 AM

I wouldn't know, as both of our SD's lack a belt also(I cut them off, both have failed compressors

). The 300D has a belt and it seems to engage and operate...but blows fiercely hot air when in A/C mode (heat mode too)!

I am guessing monovalve....

2.5Turbo · #10 04-03-2007, 08:37 PM

I notice it taking off from a stop. It's pretty bad until the turbo builds up boost. I also notice it cycling while cruising. I'll be cruising along and all of a sudden I will start to gain a little speed. Back off a little, then I start to lose speed...Kind of a pain, but I've only really noticed it a few times.

My engine braking performance also goes up a little bit when the AC is on. It's great knowing that some of that excess energy is going somewhere useful.

t walgamuth · #11 04-03-2007, 10:09 PM

it seems like the ac takes maybe as much as 20 hp to run.

i used to routinely shut it off when passing in a 240.

tom w

300SD81 · #12 04-03-2007, 10:15 PM

It'd be nice to know what ref your running in those... R12, R134a, or alternative?

tarbe · #13 04-03-2007, 10:32 PM

This thread just made my day. I recently used my AC for the first time since picking the car up in November and I thought maybe my compressor was locking up!

Not used to getting reverse whiplash when I turn on the AC

rg2098 · #14 04-03-2007, 10:53 PM

Want to hear something amusing about the Yorks? Citroen SM's used an "intermediary shift", that ran through the engine and out to the front to drive the accessory pod (hydraulic pump, P/S pump, and A/C). Well the 4 camshafts were also driven off this shaft and there was a problem with it snapping when the massive York compressor was engaged suddenly.

300SD81 · #15 04-03-2007, 10:56 PM

Anyone ever thought about connecting a relay on the compressor clutch wire to the kickdown switch?