Chevy HHR Network - Power loss when the AC is on

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- - Power loss when the AC is on (https://www.chevyhhr.net/forums/hhr-ss-45/power-loss-when-ac-42592/)

I guess the same for hp loss 5 to 10 hp, I guess that the dyno pulls never get into this power loss to determine the exact amount, I don't have access to make a run or 2 but it would be interesting to find out

Quote:

Originally Posted by Snoopy (Post 666175)

Generally motorheads will say 8-10 HP. But frankly every vehicle and matching a/c system is different. The auto industry statement is usually 5-8%...again depending on vehicle and system (at least that's what GM Engineering once stated).

Some years ago, it was 10-15%. But technologies have improved.

Oh, and on my use of the ac unit....as some have stated, almost all the time because of the climate......even sometimes with the sun roof open.

Also I think you'll find that the use of the ac is more noticeable when in traffic and stop and go. It's the heat build up under the hood. Once you clean out the hotter air, like using the Interstate, it is less noticeable.

Thats so true. When I'm running my bod sensor and the torque app the intake temp is outrageous with the ac on. If I sit at a red light for like 30 seconds it may go from like 95 to 150 degrees. When I'm on the highway in about 92 degree weather it reads 96 degrees for the intake. Plenty of air coming in. But I was shocked at how hot the underhood temps go with the ac on.

Look into reflectix heat shielding wrap. It makes a world of difference in heat soak. I wrapped my box and inlet tube. Now I notice very little difference between hot days and cool nights. It also lessened the effect that the AC had on power loss due to less heat soak. It's about 16 bucks at Lowes plus another 10 bucks for some extreme duty double sided tape and metal reflectix tape. This is one cheap mod id recommend to anyone.

I dunno. The HHR SS engine likes to run hot. It may just be load on the system. I'm not sure how well wrapping the intake/inlet will work. I'm willing to try wrapping the hotside pipe to see if that helps some. I just press harder on the accelerator when the A/C is on and all is good.

Well it's an easy mod and cheap and totally reversible. honestly this is the first vehicle I've needed to wrap my intake to control heat soak. I've never noticed such dramatic heat soak in an NA motor before.

Breadfan I here ya
My SS seems to run better when its HOT also
As far as feeling the ac come on I have seen some really drain power when they are loaded up with ac sealer and too much of it.
Had one in a couple years back trying to diagnose why the motor would shudder and loose power turned out TOO much ac refrigerant and too much sealer.
I would pull up the specs on the AC and check the low side pressure and temp output of the ac ducts if you suspect someone may have added sealer or too much refrigerant.
usually a tell tale sign is when you pull the low side ac cap and you see the HIc ecto cooler glow in the dark looking green stuff there you will know
you southern guys get too have the ac on most times and us in the north usually use the heat alot even in the summer mornings and evenings.This year has been really hot so using the ac more an more.

Your MPG drops too with AC. I see about 3-4 mpg drop.

Quote:

Originally Posted by Old Lar (Post 666265)

Your MPG drops too with AC. I see about 3-4 mpg drop.

It's worse with the windows/sunroof open at speed. But I'm blessed with living in a climate that makes that kind of motoring wonderful so for me it's a good tradeoff to being hermetically sealed up all the time. :cool:

RoadDawg831, I could swear I saw a Red HHR SS just like yours near/in Lodi a few months ago. Was that you?

I roll the same as you, no A/C all windows/sunroof open.

Don't know if this is 100% true or not, but I've heard that when at WOT with the A/C ON, the A/C clutch will disengage until you are no longer at WOT. Had a buddy try it at the drag strip. Turned the air on and pulled the knob off so he couldn't turn it on...ran identical et.

Again, don't know if its true or not or if it was just a fluke on his part.