A/C Restoration

SeaDweller · 05-01-2002, 05:11 PM

Well, I just finished my part of the A/C restoration of my SC. I have an under-dash unit in my Euro car, and literally removed every part of the system. I spent the better part of 20 hours running brand new barrier hoses and cleaning all the components. I also spent a small fortune on a new Sanden compressor, late model rear lid condensor, SPAL evaporator and quarter condensor fans, etc. Any part that was not replaced with a new one was send out for flushing, cleaning, testing, etc.

The SC is now at a local shop that does custom A/C work, as fittings will need to be custom made to accomodate the later model components. They're going to install the fittings, button the system up, and charge it with R12. If this system doesn't blow cold when it's done, nothing will....

I'll let ya'll know how everything turns out, and will post some pictures of the work......It was a chore, but it's hot as hell in Florida right now, and the survival instinct causes Porsche owners to do crazy things!!

Joeaksa · 05-01-2002, 05:19 PM

Michael,

How much trouble was it running the new hoses? Did you get them made locally or purchased as a package?

I am still sitting on the fence regarding my hoses and really want to do the new barrier hoses but do not want to ground the car for a long time.

Joe

SeaDweller · 05-01-2002, 05:39 PM

I bought bulk hose from Tim Bohringer at ackits.com. It wasn't feasible for me to run pre-made lines (with the fittings attached), as it would have been a nightmare. First of all, I have an unusual, aftermarket system, and second, the fittings would not fit through the holes that the hoses run through. I simply cut the fittings off the old hose (they can sometimes be reused), pulled the old hose out of the car, and ran the new one's.

I did re-route some of the lines, as I'm using a later model condensor that is quite different than the original. Running the new lines was time consuming, but not difficult. Jacking the car up to get into the wheel wells made things much easier. It took me a good week to do it, but that's working a few hours here and there after work, getting interrupted, etc. I'd say it could be done over a weekend.

Regarding the hose, the pre-made hoses are ridiculously expensive. To give you an idea, I bought some 50 feet of hose from ackits.com for around $80 delievered to my door. Porsche wants a fortune for a single line, and my local hose place (Goodyear) wanted over $4 a foot for the same bulk barrier hose. I'm having the fittings installed now, and I believe it's in the neighborhood of $5 per fitting.

Joeaksa · 05-01-2002, 07:33 PM

Michael,

Thanks much and since I am right down the street from Ackits, I will give them a call. Good idea on runing the bare hose then putting the ends on later.

Thanks,

Joe

SeaDweller · 05-02-2002, 04:00 AM

Ah, I just noticed you were in Phoenix!! They also have a board over there that was enormously helpful with A/C questions.....

Joeaksa · 05-02-2002, 06:00 AM

Posted on the board there and have not heard from them but one individual got in touch with me directly. He is helping me overhaul my compressor and after talking with you believe that I will replace all my hoses with new. Emailed with Tim last night and will call him today.

Just not excited about putting fresh R-12 in the system and having it leak out of the old hoses! The jury is still out on the underbody condensor...

Thx,

Joe

SeaDweller · 05-02-2002, 06:54 AM

Indeed, at $40/pound for R12, the hoses will pay for themselves in short order!!!

I looked at the underbody condensor as an option, but it's quite expensive, and looks awfully vulnerable to me. When I first bought my car, the A/C worked fair I would say, and that was with a half-assed R134 conversion, and what turned out to be a blocked evaporator. Basically, there were two patches of what looked like paper, "glued" to the evaporator fins right in front of the blowers. Without proper air flow through the evaporator, the system will never work properly.

I had the charge brought up to the right level, and the system blew pretty cool air, despite all of the problems. As such, I figure with everything working perfectly, and using R12, I should have a pretty good performing A/C system.

One thing I did consider was a DIY evaporator/blower assembly, which would be pretty easy to construct. I was thinking of making it out of Starboard (typically used for boat doors, hatches, etc.) and simply mounting it in the smugglers box. I figured I could then myself determine evaporator and fan size. There's a company that has a really, really nice underdash air distribution system for the 911:

www.scottsind.com

I could run a hose from my DIY evaporator/blower in the smugglers box, to this air distribution system, and really get serious air flow, however there's a caveat.........

I've been trying to determine why 911 A/C doesn't work well, because as I've mentioned before, the A/C in my VW Super Beetle would freeze you out of the car, but it was an under-dash system. I'm convinced that the primary issue with factory 911 A/C is that the air flow through the system stinks, and air flow is critical for optimum A/C performance.

The reason for this?

I believe that with the evaporator/blower mounted in the smugglers box, the system is restricted as to how much air it can draw, which in turn restricts its output. My under-dash A/C system has the evaporator/blower assembly in the cabin, so it has a large volume of air to draw from, unlike an assembly mounted in the small, smugglers box. To make matters worse, the evaporator/fan assembly takes up almost the entire smugglers box, so how much air is available for the system to draw? It's like taking a huge breath through a straw as compared to a 4" piece of PVC!!

I think one of the keys to maximizing the performance of 911 A/C systems is to get more air to the smugglers box. Whether that means venting the cover, or routing a hose to the fresh air system, I don't know.......

In any case, I'm hoping to get the car back tomorrow, so I'll post the results of the work......Hopefully they'll be encouraging!!

Joeaksa · 05-02-2002, 07:07 AM

Michael,

I completely agree that there are a lot of shortcomings in the 911 A/C system. Had even thought of one time trying to put a boost fan in the pax footwell to help get more air in the system but got busy with other projects.

Do not like the underbody unit that much either but have talked with several guys who love it and say it works well. In our (FLA and AZ) heat the normal system just is not enough in August...

Joe

Joeaksa · 02:50 PM

Just off of the phone with Tim of ackits.com and he is very helpful.

How many foot of hoses did you order? Thinking that 40 or so should do it. When you look at $1.50 a foot for hose and $1.50 to $10 a fitting, its a lot less than what the "hose kits" are selling for on the internet.

Tim said that they could crimp one fitting on the hose then it could be run through the body and clamps then drive back to the store and they would crimp the other fitting on the hose. Assume that this is what you did?

Also noticed that they sell aux condensor units (http://www.ackits.com/content/cddata/mfcond.htm) that look very interesting and might be a way to cool the car down enough to endure a summer in Phoenix or Florida.

Let us know how it goes on your work with the A/C!

JA

SeaDweller · 05-02-2002, 04:06 PM

I think I bought 30' of the 13/16" hose, and 20' of the 5/16" hose. I ended up with about 5' of extra hose, but at $1.50/foot, I preferred to err on the side of caution.........

I don't have the factory A/C set-up, and being that I changed the lid condensor to a later model version, and had fittings in different locations, I ended up having the A/C shop that's finishing the job put all the fittings on. They'll have to put special bends and angles in the fittings to wrap around hinges, connect to the dryer and evaporator, etc., so off-the-shelf components wouldn't work in my case. Also, I have a quarter mounted condensor (funny they did this back in '78, and now Griffith's has their Kuehl condensor), so it must have been a pretty hip setup in its day.

If you have factory A/C, and you're not changing any components (or locations of), then you could definitely have the fittings put on one end of the hose before installation. Then it's just matter of running the hoses, getting a few more fittings installed, connecting everything up, and charging it (after it's vacuumed down of course). If you suspect the system might be contaminated in any way (or if it's been open to air), change the dryer (I'd do this regardless) and the expansion valve while you have everything apart.

I'm crossing my fingers that the car will be done tomorrow, and I'll post an update if that's the case.

Later...........

SeaDweller · 05-02-2002, 04:16 PM

By the way, don't go by my hose measurements, because my system is quite different than yours (at least the location of some of the components). Your dryer is probably in the drivers side wheel well (mine's in the smugglers box), and your second condensor is probably in front of the gas tank (mine's in the rear quarter).

On thing that's really neat about my system (it looks like some engineering thought actually went into it!!), is that the refrigerant is sent to the quarter mounted, fan cooled condensor first, and then to the lid mounted condensor. I believe this was done deliberately to cool the refrigerant somewhat before it hit the lid mounted condensor. Being that the air that cools the engine comes through the lid mounted condensor, it looks like their idea was to reduce the temperature of the lid condensor so cooler air is fed to the engine, rather that very hot air from the condensor.

On factory systems, it goes first to the lid mounted condensor, and then to the front condensor. I can see where using the A/C in the summer might lead to higher engine operating temperatures with the factory set-up, because with the lid condensor first in line, it must run very hot.....

PDACPA · PDACPA's Garage

Sea did you get the car back? Did the A/C improve?

I am in Tampa too and driving the car during the day in the summer with a shirt and tie is impossible!

Joeaksa · 05-07-2002, 04:49 PM

He got the car back, the A/C works great and then he went on vacation the next day! Do a search and you will find his new thread on this. Once he returns he has promised us a complete review on this.

Gotta keep Momma happy!

JA

PDACPA · PDACPA's Garage

Not to sure how to do a search for his specific post. Can you post a link?

Any idea what the cost was? Wanted to pull the 911 out today, but have a few meetings and the starched shirt would be soaked in sweat with this heat we are having!

Joeaksa · 07:25 AM

Try:

She's Cold as Ice!!!!!

Posted on the 3rd by Michael. If the above URL does not work, do a search on "cold as" in the 911 forum and you will find it.