A/C ? for people with under car condensor

JeffW · 08-01-2002, 11:44 AM

I talked with scott inc (performance aire) about their undercar condensor and I'm almost ready to buy but I'd like to see a picture of how far it hangs under the car. I can just see going down the highway and hitting a bottle or something. Also they say that the undercar cooler should be the first condensor in line and the trunk be the second, which kinda makes sence. I'd imagine you'd want to disapate heat over the largest surface first for better efficency. I'd like a side view since all they have is under car. Thanks.

pbs911 · pbs911's Garage

I kow Jack O did this. I saw BB last weekend and checked out the under-body condenser. It looks like it hangs down no more than 2 inches. Nonetheless, it looks like a close call for those very tall speed bumps on a lowered car.

Eric Coffey · 08-01-2002, 12:39 PM

Couldn't you fabricate a protective guard/grate like the factory used on the Carrera-style front condensors? Also does this system still include the rear deck lid condensor? If so, I thought it was typically the larger unit? Where does the "undercar" one mount? Please shed some light.

Ron,K · 01:18 PM

Attached is a picture with the underbody condensor installed. While it's a little dark, I think you can get a general idea of the clearance. Keep in mind that I also have hard oil lines installed in the same area as the A/C lines, so it looks a little cluttered. My system uses the original condensor on the deck lid but as mentioned earlier, freon flows first through the underbody condenser then to the rear deck condenser. The rectangle in the picture is roughly where the condensor is intallled.

JeffW · 08-01-2002, 01:27 PM

That doesn't look so bad. for the price I don't think you can beat it. Did you have a factory condensor? Was it a single pass or double pass condensor? I think Mine has a single so I'm going to have to upgrade to a larger one. My problem is my car is going to be ready for paint soon and I don't want any problems with that system getting in my way.

Joeaksa · 08-01-2002, 02:06 PM

Jeff,

There is a SC in Tucson with the underbody condensor.

Call Iron Horse Motorcycles on Grant Road and tell them that you are looking for the BMW bike owner that has a white SC 911 and they should remember him. If not ask for Marty, the owner and ask him.

I met the 911 owner there the last time I was in Tucson and looked at his car then. Its not that obtrusive but still does hang down. Would be nice if you could look at one in person before buying...

Joe

JeffW · 08-01-2002, 02:50 PM

Thanks Joe, I'll see if I can arrange that. I would really like to see one but I guess if jack put one on his car it can't be too bad. I'm kinda going for the same thing with my car, creature comfurts and trackable. The hose arangement they are suggesting looks to be quite a pain. I will need 2 extra hoses running from the unit back into the engine compartment but I guess its worth it. $1000 in condensors is alot to pay for a under car and trunk mount.

Joe, do you know anyone around that will pressure test an evaporator?

Jack Olsen · 08-01-2002, 03:57 PM

Here are two pictures of the under-belly condenser on my car.

Keep in mind, the stock height for my car is 26.5 front, 26 rear. Euro height is 25.5 front 25 rear. My car is 24.5 front 24 rear.

So the fact that the clearance is just under four inches would be mitigated by your (probably higher) ride height.

In any case, low points between the wheels are less likely to cause contact problems than ones in front of or behind the wheels. My rear sway bars hang lower than my condenser. But the only things I worry about scraping are my valence in front and my muffler in back.

As a side note, my shop modified my condenser so that the hoses entered and exited on the same side, bringing the one line that was not being utilized back into the system. I don't know why they come plumbed for entry/exit on opposite sides.

Fishcop · Fishcop's Garage

I have condenser and fan in front of the LR wheel up inside the arch. Could this be a viable alternative for you? I can post a photo if you need.

Jack Olsen · 08-01-2002, 05:54 PM

I had the rear fender condenser, as well as the stock front one. In my case, it wasn't enough. The belly one is very big. compared to other options.

JeffW · 08-01-2002, 06:31 PM

Thanks Jack, That is exactly what I was looking for. I think that will work for me. Did you use a factory rear condensor with that or some aftermarket?

WydRyd · 08-01-2002, 06:38 PM

Thanks Jack. I'm looking at doing the same to my Carrera.

How does it perform with just the under-pan & under-trunk unit?

How much does it weigh?

Joeaksa · 08-01-2002, 07:45 PM

Jack,

Did you end up using three condensors? Front, middle and back or were you able to eliminate one or two of them? I would love to get rid of one of them and use the underbody one, but which one to eliminate?

Taking the front off would give me more room for a proper oil cooler installation, taking the rear off would decrease the temp of the air entering the motor by way of the grill... not sure which one would work best.

John,

Which type of front fender condensor is yours? Did you eliminate any of the others or just use it to suppliment the system?

Thx,

Joe

Jack Olsen · 08-01-2002, 07:49 PM

Right now I'm using the factory front condenser (with fan) and the under-the-belly one. I use a 964 decklid for street driving, so the rear decklid one wouldn't work.

But I think it's best to avoid the rear one, in any case. Extracted heat gets sent over the cylinders, and weight gets added high and in the back. I think the ideal setup is the front one and an under-the-belly model.

38 degrees in ambient 85 before the temp switch shuts it off.

Joeaksa · 08-01-2002, 08:33 PM

Jack,

Between your experience and that of Fishcop's I am now thinking of taking both factory condensors off, putting one underbody unit and one in the left front fender.

This would eliminate the warm air going in the motor as well as another 5-7 pounds in the rear. Taking the stock front condensor off would give me more room for a proper oil cooler up front and increased fin area and better cooling with the one in the fender. Will have to remove the windshield washer tank but can find another home for that up front.

Thx,

Joe

JeffW · 08-01-2002, 09:17 PM

why would you even need 2 condensors with that big thing under the car? That should have more surrface area than most cars currently on the road.

PDACPA · PDACPA's Garage

Would any of you guys have any ball parks of what these AC upgrades cost in parts and labor (seems like everyone has a shop do the work as opposed to DIY).

I am trying to budget how much I need to get my exisiting factory system upgraded and working. Thanks.

JeffW · 08-02-2002, 07:39 AM

I'm doing my own work. Hoses if you have them built run under $150, under car condensor is $395. Its going to cost me around $1500 to get mine working with all these parts. I have decided to get a front condensor with fan and go with the under car condensor also.

PDACPA · PDACPA's Garage

My system has the original hoses, the condensor under the Carrera wing on the rear and the front condensor. I believe the compressor was replaced in 96.

I think new hoses is for sure on the list (not sure I want to run them!).
The underbelly for extra condensor is a must.

Contemplating replacing the other parts rather than do it half way, but does anyone know if you can keep the compressor if its functioning ok?

JeffW · 08-02-2002, 07:56 AM

The compressor is probably fine but if your going to run r-12 I'd replace it anyway. The cash you loose when r-12 dumps is about what a compressor would cost you. I'm going to go with R134A and if you add the underbelly condensor I recommend you do also for the simple fact that you now have the needed condensor space to make R134 cold enough to work properly. The underbody condensor comes with an installation kit. I have a York compressor so It's a no brainer to swap it out.