How's your A/C holding up this summer?

[mthomas58]

With what seems to be record highs all across the country this summer, I thought I'd ask how your A/C is doing and what you plan on doing about it (if anything). I'll start.

We've been in the high 90's for the past two weeks in Atlanta....hard to even go outside. Morning commute no problem as ambients are in the high 70's to mid 80's with vent temps in the mid 30's. Afternoon commute not as good but bearable - today it was 95 on the way home and I was getting consistent vent temps in the low 50's on the move and the mid 50's in stop and go. Going out to lunch and getting in a heat soaked car is a no-go ....... A/C is fighting a losing battle....vent temps in the 60's

My next step is to replace my evap (slight leak -oil found in drain puddle) with a Kuehl, re-seal the evap box, replace the expansion valve, replace the front condenser with a Rennair desert duty unit and add a procooler. I've already added three puller fans on the rear condenser and one in the footwell at the intake and think they help a lot.

[scottb]

Mark: The key to improving the a/c is increased condenser surface. Many people (myself included) have added an additional condenser/fan combination in the front left fender area; replacing the washer bottle and vapor recovery tank. Others have added underbelly and rear fender condensers. (Do a search and you'll find threads on both of these upgrades.) While replacing a leaky evaporator and installing a ProCooler (or a home brew subcooler) will help, if you want cold a/c (in the mid to upper 30s), you're also going to have to increase your condenser surface.

[mthomas58]

Originally Posted by scottb

Mark: The key to improving the a/c is increased condenser surface. Many people (myself included) have added an additional condenser/fan combination in the front left fender area; replacing the washer bottle and vapor recovery tank. Others have added underbelly and rear fender condensers. (Do a search and you'll find threads on both of these upgrades.) While replacing a leaky evaporator and installing a ProCooler (or a home brew subcooler) will help, if you want cold a/c (in the mid to upper 30s), you're also going to have to increase your condenser surface.

I know you're right, but I've got to fix my 20-yr old technology first....evap, front condenser and one hose are orig and have got to go. If not happy after these changes, adding more condenser area will be next.

Planning on doing the install work myself.

Your A/C comments always appreciated.

Thanks!

[burgermeister]

I took the compressor out when it was time for a valve adjustment... since the system held charge for about 3 seconds, I didn't bother putting it back in. Bracket left the car last week, as I had to replace a cam oil line under the bracket... I'm good with both windows down ("dual 70" AC) up to 90 or 95 depending on humidity - as long as traffic is moving.....

When I get wealthier and older and less tolerant (38 now - some time to go), I'll put in one of thos rennaire kits or something else that pretty much replaces the stock system. Seems a perennial chore to keep the Porsche factory air going, while any 20 year old Chevy will run fine till the doors fall off...

[scottb]

If you've got an original hose, then you're really wasting your time. The original hoses are designed to leak, and that they do. If I were in your shoes, I'd bite the bullet and add the additional condenser and fan at the same time you're doing the other work. The system will be open and it will be easier to do everything now, rather than piecemeal later on.

[scottb]

Originally Posted by burgermeister

Seems a perennial chore to keep the Porsche factory air going, while any 20 year old Chevy will run fine till the doors fall off...

Actually, it's been about four years since I did my a/c upgrades (additional condenser, ProCooler, and new hoses), and my a/c has been fine ever since. The stock systems are a perennial chore, but once properly modified, they don't require any more work than, well, a 20 year old Chevy's a/c.

[mthomas58]

Originally Posted by scottb

If you've got an original hose, then you're really wasting your time. The original hoses are designed to leak, and that they do. If I were in your shoes, I'd bite the bullet and add the additional condenser and fan at the same time you're doing the other work. The system will be open and it will be easier to do everything now, rather than piecemeal later on.

How much hose fabrication work is required to add a front fender condenser?

The one remaining orig hose in my system that needs to be replaced is the return hose from the evap to the compressor...others were replaced last summer (OEM not barrier I think.....but my system holds a charge well)

[BMAN]

Well everything was going good until last week when I discovered a small leak on the rear condenser on my 930. If anyone has one that they don't need please let me know. Thanks

[bpoteat]

Originally Posted by burgermeister

Seems a perennial chore to keep the Porsche factory air going, while any 20 year old Chevy will run fine till the doors fall off...

I think we've just been in totally different 20 year old Chevys. Maybe it's the difference between 20 years of Michigan and South Carolina weather.

[scottb]

Originally Posted by mthomas58

How much hose fabrication work is required to add a front fender condenser?

Mark: IIRC, I simply installed the new condenser "in series" with the existing front condenser. What this means is that the hose that originally went to the input side of the existing condenser went to the input of the new condenser, and then I had a hose fabricated to go from the output of the new condenser to the input of the existing front condenser. Also, IIRC, I didn't shorten the hose that originally went to the front condenser. I think I looped it back to the new condenser, so no changes were made to the existing hose.

So to answer your question, if I'm remembering correctly, the only hose I had fabricated was the hose from the new fender condenser to the existing front condenser.

[scottb]

Originally Posted by BMAN

Well everything was going good until last week when I discovered a small leak on the rear condenser on my 930. If anyone has one that they don't need please let me know. Thanks

Now's the time to upgrade to one of the high performance condensers. I think www.retroair.com and www.griffiths.com sell them.

[TibetanT]

BMAN:

I happen to have a rear condensor and A/C compressor from a 1978 911SC. Will that work/fit in your 930?

Let me know.

[scottb]

Ed: The 930 has a large condenser. Your 911 condenser is likely much smaller.

[craig001]

IIRC, folks have had some decent results with the Pro-Cooler set-up. Just wish there was a kit for the 964.

[TibetanT]

Scottb:

That's what I thought...too small.

Thanks.

[BMAN]

Originally Posted by TibetanT

BMAN:

I happen to have a rear condensor and A/C compressor from a 1978 911SC. Will that work/fit in your 930?

Let me know.

Thanks, but no it needs to be from a Turbo car. The turbo cars have a smaller one due to the intercooler. This is the one I need,

[scottb]

Originally Posted by craig001

IIRC, folks have had some decent results with the Pro-Cooler set-up. Just wish there was a kit for the 964.

Do a search for posts by Jim Sims and Hugh R about the "home brew" subcoolers they've installed on their cars. Jim sourced the parts and explained how to install it. My guess is you could build one to fit your 964.

Also, have you contacted Ron Maxwell at Rennaire to find out if the ProCooler can be adapted to a 964?

[jhubs]

Mark, I followed your lead and added a pull fan to the rear condenser. Here are some photos of the work completed today. The SPAL fan is a 7.5 inch and pulls 440 CFM through the condenser and into the engine compartment. The fan is very close to the engine air intake so I figure I now have a 3.2 TURBO!!



Right side wiring:


Left side wiring:




I still have the R12 system and I had one of the hoses on the right side of the condenser replaced as it was rubbing on the engine deck lid hinge and leaking. Our temps in Colorado have been consistently in the mid to high 90's all summer. Global Warming?!!???! We have what some people call "dry heat" here in Colorado but HOT is HOT. I'll post some other AC modifications. So far I have about $500 invested.

Your previous posts about your AC improvements inspired me, so THANKS!

[Hugh R]

I did the Jim Sims subcooler for something like $20, plus the cost of twos, additional hose. Instead of one hose from the front condensor to the evaporator, you need one to the subcooler from the front condensor and another from the sub to the evaporatorand the same thing back from the evaporator to the compressor. Makes sense if your going to make all new hoses. Add in an additional 200 or so bucks for that. Do a search on Jim sims subcooler and you'll find it in one of the threads along with where he (and I) ordered the subcooler. You'll need to silver solder or braze in a couple of compression fittings from Home Depot. After soldering, pressure test it in a bucket of water to check for leaks. You can use your air compressor set as high as possible. You can only use compression fittings, the o-ring ones from an A/C shop won't work they're made of aluminum and you need brass to solder. It does essentially the same thing as the rennair system, in that it (I think) scavenges the last little bit of cooling out of one side of the system and transfer it to the other side of the system. I'm being a little cagey here, cause I don't have my notes on what I did in front of me. I'm traveling.

[scottb]

Originally Posted by jhubs

he fan is very close to the engine air intake so I figure I now have a 3.2 TURBO!!

Wow...it looks like the fan is really close to the air intake. Are you at all concerned that it might restrict airflow to the engine?