Remove decklid condensor, keep A/C?

Pazuzu · 06-21-2008, 02:13 PM

OK, here's one for the A/C experts.
My 80 has aftermarket additions to the A/C system...a rotary compressor, extra vents in the cabin, and most importantly, a giant underbody condenser. It's probably 16 inches wide and runs the width of the car. It also still has the stock nose and decklid condensers.

I want to remove the decklid one for better airflow into the engine bay. Do you think this large but passive condenser under the car would make up for the small but active one in the lid? By passive, I mean that air probably does not flow *though* the underbody one, but does flow along the face of it. It does appear to be slightly separated from the undercoating, so there's some airflow on each large face.

I do not know the name of the additions I have, nor their specs, other than the fact that my 80 has better, colder air than my 2006 Mazda3.

Gimme ideas, suggestions, requests for more info so I can properly help YOU to help ME

York · 06-21-2008, 02:22 PM

I am not an A/C tech, but I doubt that you would be happy with the cooling if you shed the decklid condenser unless you add electric fan(s) to the underbody unit to get good airflow through it.

Pazuzu · 06-21-2008, 02:24 PM

There's no way that fans are going to work down there

I guess what I need to ask is will removing the decklid piece still give me moderate, 911 style cooling, since I currently have very NON-911 cooling? Obviously, part of the quality is having 3 condensers, and removing 1 WILL impact the system...

York · 06-21-2008, 02:43 PM

I am going to guess no, that you cannot remove the decklid unit, I just don't think the others will shed enough heat. The front condenser and fan is likely too small to pick up the load. I have never heard of an underbody condenser on a 911, seems like a poor location for several reasons. Usually an aux condenser is located in the front wheel well with a fan.

Zeke · 06-21-2008, 02:45 PM

Well, 964's don't have a deck lid mounted condenser that I know of. I have a 964 lid on my '88 and had to lose that condenser. The advice I got was to use a 964 front fender mounted condenser AND the desert duty one in front. I haven't gotten that far and it looks like I will miss this summer having AC. So, maybe next year if I still have this car.

York, there are underbody units and they get pretty good air flow when moving.

I will subscribe to this thread.

Pazuzu · 06-21-2008, 02:46 PM

Yes, this underbody unit surprised me as well, I think it's the massive surface area that help it work. I haven't gotten under it enough yet to see what else is down there, but the condenser is clearly visible just by laying on the ground.

Has anyone ever found a smaller decklid condenser? Maybe a half sized one that will help cold air flow into the engine bay, while still contributing to the A/C system? Hmmm...

Pazuzu · 06-21-2008, 02:48 PM

Oh, and I know that I have some options like the Desert Duty stuff, but I would like to do this for free or nearly so

If it's going to cost me money, I'll simply live with what I have, and get a fender oil cooler to help with the engine temps.

Ryce Stallings · 06-21-2008, 02:54 PM

I believe the system you are describing is sold by Performance Air. They are designed to work without the rear condensor, just the large underbody one. You should call them. The compressor your have should be a Sanyo if it's their unit. I have one on my car and the underbody units probably doesn't work very efficiently when the car is caught in traffic and the pavement is at 160 degrees.

York · 06-21-2008, 03:00 PM

I have wondered this also, has anyone done any testing to see how the decklid condenser affects air flow rate and how much heat is added to the air going into the engine for cooling?

Jack Olsen · 06-21-2008, 04:03 PM

If you have the front condenser and the Performance Aire underbelly model, then you already have a lot more condenser area than the stock setup. I ran with just those two (front and belly) for a long time and the system worked great.

However, I don't think you're going to see any significant difference in airflow to the engine itself with the condenser removed. Are you concerned about your running temps?

Pazuzu · 06-21-2008, 04:19 PM

Quote:

Originally Posted by Jack Olsen

If you have the front condenser and the Performance Aire underbelly model, then you already have a lot more condenser area than the stock setup. I ran with just those two (front and belly) for a long time and the system worked great.

However, I don't think you're going to see any significant difference in airflow to the engine itself with the condenser removed. Are you concerned about your running temps?

I'm still trying to find what condenser this is. A shop in Dallas installed it as part of a "generic A/C upgrade" in early 1997. It's listed as "1445A Aux. Condenser" on the paperwork, but that's it...being 11 years old, it might not be a Performance aire system, but I'm sure it's similar in use and results.

The compressor is a SD508.

I'm not *concerned* about engine temps, but I also don't want to ever HAVE to be concerned about them. I have a Carrera tail also, not the flat decklid. I'm not sure how that changes the airflow dynamics.

Ryce Stallings · 06-22-2008, 04:57 PM

I want to correct what I said about the Performance Air system I had on my car. It did have a rear condensor also. If you have the front and belly condensors that should be enough.

Sorry

squelch · 06-22-2008, 06:42 PM

This guy did it. His article may be helpful: http://www.pcaucr.org/site/page.jsp?pageid=221