Best ac mods for 1987 Carrera

[si Banker]

What is the best course? Stay with r-12 or go to something else?

The car has front and rear condensers; the system is bone stock.
I thought I would do the following:

Change hoses
Put additional fan on rear condenser

I am open to suggestions on the rest.

[jorian]

Start with a recharge if you can find someone willing to do it.

[si Banker]

I have access to R-12. It is not cheap but I can get it. I don't know if I should change the hoses and still use R-12. I have heard it has the best capacity for cooling.

[Rot 911]

This is a subject that has been discussed thoroughly on this board from changes to R-134, to new systems to placement of various condensors. A search will give you much information my friend.

[RickM]

You may want to start with a search.

Seriously, there's literally hundreds of pages of suggestions and experience on the subject.

Some have gone with parralel condensers. additional evaps/conds, larger (some much (belly)) condensers, Pro-cooler, Bowtie modification, additional vents, more efficient compressors......etc.

BTW, welcome to the board.

[jtratza]

What vent temps are you getting? My 1987 AC is also still stock other than taking off the vent diverter on the center floor vent. I have replaced the compressor, evaporator, expansion valve, thermostat nad the receiver dryer over the years but stayed with stock parts. There in is where I think some people get into trouble with their system. It hasn't been maintained. Last year I had some seals replaced and the sytem filled by an AC shop here in Houston. The owner spent a hour adjusting pressures and since then I've been getting approximately 50 degree discharge air on 90 degree days.

As to upgrades from what I have read over the past few years I'd do the following when needed:

Replace the evaporator with a modern one
Add a condenser under the car or in a wheel well
Somehow get more air flow out of the vents. One of these days I'd like to figure out how to tqake the clock out and replace it with a vent of the AC system with a fan in the clock face.

As long as I can get 50 degree discharge I'm ok with the system. I'll admit that is still marginal during a Houston summer especially when I drive the wifes X5 with 40 degree discharge and a fan that can fly a kite but some of upgrades I have seen are better spent on driving upgrades and DE events IMHO. If its real bad inside the cabin I can always take the roof off and enjoy the sunshine. Not effective in traffic but then I shouldn't be in any.

32 degree vent temps with r134a???? yup....

[jtratza]

I saw that on an earlier post Mark. That is awesome. Now I know where to get ice for this summers gin and tonics. How do you keep the evaporator from icing up. I think I'm getting some icing and I'm not getting near the temps you are seeing. I'd rather get more air flow. Have you done anything there?

[masraum]

What's the problem if the evaporator is icing up? Too much freon, too little?

[jtratza]

Not sure what causes it. I just notice the temps are not going as low and I get lots of water under the car when I stop for a while. Marks' evaporator set up is the next mod when mine begins to leak or the expansion valve quits. Or I get some engine work done and have money left over before the daughters get it.

[ruf-porsche]

Once the evaporator starts icing up, the air will not be able to flow thru the evaporator, but instead flow around it. With the air flowing around the evaporator instead of through it you don't have the heat transfer for the air, so the air coming out of the vent is not as cold as it should be.

Evaporator icing up is usually related to the compressor not cycling off. Check the location of the freon tube for the thermostatic switch. Is is the tube from the temp switch to the evaporator.

Water from your evaporator means that the drain line is probably plug

[jtratza]

Thanks Ruf I'll check both this week. I know we were fooling around with the freon tube a couple of years ago and it has been a concern since then.

[scottb]

If you're serious about a/c, here are some suggestions:

1. Replace your hoses with barrier hoses.
2. Don't bother with a fan on the rear condenser. It won't help much (if at all). Put a third condenser, with a fan, in the front left fender. Some people have put them in the rear left fender.
3. Clean out and re-seal the evaporator box.
4. Install Griffiths' Kuehl vent, or so a search here on the board for Don Plumley. He made his own vent, and it's pretty slick.
5. I added a ProCooler. I think it helped, but others think it's snake oil. With the auxiliary condenser, I'm getting vent temps in the mid-30s.
6. Charge with R12. It's more expensive than R134, but cools better. Be sure you use a shop that knows what they're doing when it comes to Porsches. You have to recharge with the rear deck lid down.
7. If you're REALLY serious, you might consider the Performance Aire under-belly condenser instead of a fender condenser.

Let us know what you decide to do. Good luck!