Let the AC fun begin....oh to blow 45!!!

[tsuter]

So the move to Texas went well...thank you but.......
It's time to resurrect the factory AC in the 78SC with 134a.

Question one. Is this the right pump to buy if I can get it at a San Antonio pawn shop for $95?? You know the place where they steal stuff off construction sites and pawn it. I can see oil thru the little window.....and it "looks" OK. "Like new"!!!

ROBINAIR 15434 - A/C VACUUM PUMP 4CFM 2-STAGE R12/R134A 1/3HP 20-MICRON



Question two... There must be a better rear condensor than the 28 YO one I got on the shelf. Like one that will go up in the turbo tail and be more efficient?? I got lots of room. Who? Links??
Not like my old stock "inside the rear deck" one pictured....



And last. Any reason not to put a 10" Turboflex fan like this up in the back with whatever rear condensor goes up there??



Oh, and this is Texas...no under belly condensor.... no way no how...but ProCooler yes for the receiver/drier.

[skipdup]

tsuter- You should really check out my system. Everyone that knows old 911s and rides in my car can't believe how cold it blows... seriously.

And, you couldn't take my under belly condenser away from me at gun point. Everything I've read about them is just false! They work!

- Skip

[bonaturtle]

Where is the info on your system, and does it work on G50's? I need colder air in my car, current one struggles to do that.

[tsuter]

Originally posted by skipdup
tsuter- You should really check out my system. Everyone that knows old 911s and rides in my car can't believe how cold it blows... seriously.

And, you couldn't take my under belly condenser away from me at gun point. Everything I've read about them is just false! They work!

- Skip

When can I see it?? I'm planning a run up to Rennaire soon.

I think the under belly condenser works, it's just that I've hit so much debris on the roads here in Texas in both cars that I'm now looking for an under belly skid plate for the VW before I lose an oil pan. The 911 there's not much to damage...at least not yet.....

[skipdup]

tstuter- PM sent.

bonaturtle- was that post for me?

- Skip

[Craig 930 RS]

SPAL fans are the best available -

[thinkfloyd14]

this may be a stupid question but how much horsepower would be lossed if I put AC in my car??

[skipdup]

My garage is currently 89 degrees. RPM ~2,000. Fluke 62 Mini IR thermometer.

I have no idea if this (the picture below) is an accurate way of determining auto a/c effectiveness. But, I've seen this type of picture before, so I figured I'd see what mine would do.

What I do know is that my a/c is freakin COLD. Even during this past August (which was a record breaker), on 100+ days, I can not leave the a/c on "3", it gets too cold - even in stop-and-go traffic - which is supposed to be detrimental to the underbelly condenser.

And, I am a sweater. I'd keep my home a/c down well below 70, if it wouldn't cost me a divorce.

The system was installed four years ago by the previous owner. Dallas EuroCars is the shop that did the work. I've owned the car for over two years. It has a huge underbelly condenser just behind the front tires, has a rotary sanden-type compressor, runs R12, has a fan on the rear condenser, had all the hoses replaced, had the dryer replaced and had a center vent kit added.

I don't love that it runs R12. But, it hasn't been serviced in four years (no leaks) and my mechanic can still get the stuff - even though it's expensive.



- Skip

[Motorhead-45]

Originally posted by tsuter
Question one. Is this the right pump to buy if I can get it at a San Antonio pawn shop for $95?? You know the place where they steal stuff off construction sites and pawn it. I can see oil thru the little window.....and it "looks" OK. "Like new"!!!

ROBINAIR 15434 - A/C VACUUM PUMP 4CFM 2-STAGE R12/R134A 1/3HP 20-MICRON

The Robinair 15434 is a good choice. New they are over $200.00 so if you can find a "like new" pump that "hasn't been stolen from a construction site" for $95.00 you have a bargain. You will want to change the pump oil for fresh before pulling a vacuum. The recommended time is 3 hours at 29.9 hg's of vacuum to remove all moisture for a system that has been open.

Another bargain right now is to go buy your R134 at Sam's Club. 12 can cases of 12oz are $35.47...you'll pay nearly that much for just 3 cans at your local parts store.

[fintstone]

My system has no problem getting to 32 degrees with R134.

[Motorhead-45]

Originally posted by fintstone
My system has no problem getting to 32 degrees with R134.

Your car was the Jim Sim's upgrade car right?...that explains the 32 degrees!

[fintstone]

Yes, Jim installed my sytem. We started with a non-A/C car so we had to buy most of the parts new. We decided to use 3 condensors...an upgraded one on the engine compartment lid and the dual kuehl setup in the left wheel well. He also made the hoses using the smaller diameter barrier hoses. procooler. I had a used set of '74 underdash ducts that Jim cleaned up and resealed and a used Sanden compressor...Jim bought a used later model Behr style blower/evaporator box and replaced the evaporator with an upgraded one. Perhaps that was a little overkill, but was better than having to do it over. So far it works remarkably well. Jims workmanship is amazing.

[bonaturtle]

Originally posted by skipdup
tstuter- PM sent.

bonaturtle- was that post for me?

yeah, I think you answered it.

- Skip

[Rikao4]

While Skip has not given me a ride..I have opened the door to his beast during a normal Texas day..like opening a fridge.
Rika

[Motorhead-45]

Originally posted by skipdup
My garage is currently 89 degrees. RPM ~2,000. Fluke 62 Mini IR thermometer.

I have no idea if this (the picture below) is an accurate way of determining auto a/c effectiveness. But, I've seen this type of picture before, so I figured I'd see what mine would do.

What I do know is that my a/c is freakin COLD. Even during this past August (which was a record breaker), on 100+ days, I can not leave the a/c on "3", it gets too cold - even in stop-and-go traffic - which is supposed to be detrimental to the underbelly condenser.

And, I am a sweater. I'd keep my home a/c down well below 70, if it wouldn't cost me a divorce.

The system was installed four years ago by the previous owner. Dallas EuroCars is the shop that did the work. I've owned the car for over two years. It has a huge underbelly condenser just behind the front tires, has a rotary sanden-type compressor, runs R12, has a fan on the rear condenser, had all the hoses replaced, had the dryer replaced and had a center vent kit added.

I don't love that it runs R12. But, it hasn't been serviced in four years (no leaks) and my mechanic can still get the stuff - even though it's expensive.



- Skip

24 degrees in the vents probably equates to sub 20 degrees in the evaporator box. Those are some awesome numbers but...add in some moisture from the outside air and isn't this a recipe for a frozen evaporator?

I live on the coast and if I let my vent temps get below about 38 for any extended period of time I end up with a frozen evaporator and no air flow. I'm plenty comfortable with anything below 50 in the vents and normally shoot for about 45 before backing off on the temp setting.

[ruf-porsche]

Contrary to most people thinking, having the blower at the fastest setting does not equal colder vent temp. For colder vent temp you need the blower at the lowest setting. Less air is force through the evaporator so the evaporator is cooling a smaller volume therefore the air that is does cool is colder.

Get a digital thermometer and see the vent temp at various blower speed.

[skipdup]

Originally posted by Motorhead-45
24 degrees in the vents probably equates to sub 20 degrees in the evaporator box. Those are some awesome numbers but...add in some moisture from the outside air and isn't this a recipe for a frozen evaporator?

I live on the coast and if I let my vent temps get below about 38 for any extended period of time I end up with a frozen evaporator and no air flow. I'm plenty comfortable with anything below 50 in the vents and normally shoot for about 45 before backing off on the temp setting.

To be honest, I don't know if I trust that reading. It just doesn't "seem" right. I wonder where it gets the temp reading from - back of the duct, the vent, is the air, or something else???

That said, it is still probably the coldest a/c I have ever felt.

Also, here in TX, I've never had this evap freeze. Even during periods of relatively high humidity. But, when I lived in FL, in real humidity, (with other cars) I've had it happen.

- Skip

[tsuter]

There will not be another summer in Texas w/o AC....

However, this install will be a bit unique so stay tuned.

The old A/C compressor bracket has been reinstalled after an 18 year hiatus on the shelf and now its time for some fitment.....



Fitment??? You say...Yes, because the plan is to install the newest Sanden compressor designed purely for R134a. No universal R-12/R134a combicomp for this setup!!!

The probable compressor is the SD5H14



I could tell you why but you can read about it from Sanden.



Now what isn't mentioned directly is this is an 8ci unit not 7ci. So guess what?? 14% more capacity!!!! And more refrigerant in the system! ( Does anyone know how to adjust the expansion valve??? )

But fitment.......first!! Stay tuned....

[Jim Sims]

"No universal R-12/R134a combicomp"

The above compressor is used on 911's for a reason. It has the redeeming feature of having ports at convenient locations for mounting the servicing fittings. The newer R134a Sanden compressor does not. You'll need space to deal with the harness servicing fittings and a high-low pressure switch. Plan ahead or you'll be dismounting the compressor each time you need to change the oil filter. Also, better check out the clearance of the the outer pulley groove edge to the underside of the decklid and remember the decklid over travels downward against the latch springs.

A unique installation? Almost everything feasible has been tried on 911 A/C installations. It will be interesting to see what you come up with. What would be unique and weight saving would be to render that OEM "boat anchor" of a mounting bracket in Titanium alloy or carbon fiber composite.

"Now what isn't mentioned directly is this is an 8ci unit not 7ci. So guess what?? 14% more capacity!!!! And more refrigerant in the system! ( Does anyone know how to adjust the expansion valve???)"

Neither the compressor output nor the superheat setting of the expansion valve are limiting factors on 911's; instead concentrate on condensing efficiency, air flow to the cab from the evaporator and then evaporator efficiency.

Cheers, Jim

[tsuter]

Agreed...got to watch the fitment close. What will make this unique as well may be of interest to guys with NA cars and turbo tails.