50F A/C air at 94F outsied

[stormcrow]

Well, I am finally making progress on my A/C - think I finally have figured it out. With a couple of mods that won't break the bank you can do the same.

Today, I checked my A/C out and I was getting a 52F temp on the supply air at 94F outside. The car had been parked in the parking llot for about a half hour. When I got into the car it was 110F. I cranked the engine, turned on the A/C and drove off. In about 10 minutes, the temp was down to 60F in 20 min it was down to 52F even while I was sitting in traffic. Here is what I did.

First off, I have a 78 911 SC Targa - Few years ago, I remove the outside air blower so I could make mods to the supply air on the A/C. I did some expirementing with the supply and still have a little more to do but I think I figured out how to get more air in the cabin.

Evaporator box - I removed the evaporator box and insulated it. I bought a roll of armoflex insulation tape from Home Depot and wrapped the outside of the box with it. Next, I removed the fan speed controller that is mounted at the inlet to the box. It has two coils on it to control fan speed.

Once this was removed, I reinstalled the evaporator box, and starting from the passenger side, installed the insulation tape on the face of the firewall, the inside of the box around the opening and in between the firewall and evaporator box.

Evaporator - I installed the evaporator with a 134-a Expansion valve. I did a little modification on the evaporator. Where the supply tube mounts onto the evaporator (the small tube) I removed it and installed a new piece so that the refrigerant enters into the bottom of the evaporator and leaves out the top.

This has the best effect to help in removing heat. I also tweeked the expansion valve a little being careful not to over adjust and flood the evaporator.

Blower motor - I took a pair of side cutters and cut the brackets that hold the motor to the housing. I then went to the junk yard and picked up a fan wheel and blower motor. The motor I used I purchased at a supply house, but you can use the blower motor and fan wheel. I mounted the blower motor with a plate on top of the blower motor housing and inserted the fan wheel in the underside.

Make sure when you pick up a blower wheel that the blades on the wheel are in the same direction as the old fan, otherwise it won't work.

I mounted the fan housing on top of the evaporator and gave it a test run as not to have any rubbing. Be sure the capillary tube for the temp control inserted into the evaporator or the fan wheel will catch and destroy it.

That is about it for now. The only remaing thing I am going to do is work on the air flow from the blower to the vents. I am going to increase the velocity and remove the lines that go to the side vents.

I will keep you updated with more pics as I progress. It may take awhile because I have a lot going on. I still haven't gotten to do my garage yet, but it is on the list and I should get started in the fall.

[stormcrow]

You definitely need to tint the windows. I had the rear window tinted one piece, both sides - what a difference in the heat load in the cabin.

Steve