Most effective ac upgrade

[88911coupe]

OK, already have the Sanden compressor but what is the general consensus of most effective next upgrade? It's expected to be 104 here tomorrow and I can't stand it.
Options are as I see it:
Pro Cooler
Improved evaporator unit
Underbelly condensor.
I think the first two are in the ballpark same price, however the last two reqire some hose replacement. Much of the hosing on my car was replaced by the PO. Notwithstanding the hose issue what's the most effective next step?
TIA

[PatrickB]

Originally posted by 88911coupe
OK, already have the Sanden compressor but what is the general consensus of most effective next upgrade? It's expected to be 104 here tomorrow and I can't stand it.
Options are as I see it:
Pro Cooler
Improved evaporator unit
Underbelly condensor.
I think the first two are in the ballpark same price, however the last two reqire some hose replacement. Much of the hosing on my car was replaced by the PO. Notwithstanding the hose issue what's the most effective next step?
TIA

Try the latest greatest refrigerant... Enviro-Safe - ES-12a

We beat this topic to death on another thread yesterday, and I'm going to try some in my '85 Carrera very soon. I'll post the thread, but if it doesn't work, look up topic on this 911tech BBS entitled "Info for R12 users" Some of these guys were getting amazing temps at the vents with "Stock" A/C systems...

try:
http://forums.pelicanparts.com/porsche-911-technical-forum/232130-info-r12-users-post2026306.html#post2026306

[gost]

Exactly ES-12a. Just ordered the kit and should have it replacing my old R-12 by next week. I've heard about 32 degree discharge air in a stock mid 80's Carrera system. Great stuff!

[PatrickB]

Let me know how it works out for you Gordon... I've also got an '85, and will be purchasing some very soon... Might be another 2 weeks before I get a chance to change it over... Here on the left coast, it became increasingly difficult, and insanely expensive to purchase R-12 in the last 2-3 years. I unfortunately did the 134 change 2 years ago... The 134 just can't compare with the r-12a!! I can never get better than about 30-35 degree difference form outside air temp to interior vent! Fine when the outside temp stays below 85 degrees, but anything over that is pathetic performance! I hope this stuff works!!!

Best of luck!!

[scottb]

Originally posted by 88911coupe
OK, already have the Sanden compressor but what is the general consensus of most effective next upgrade? It's expected to be 104 here tomorrow and I can't stand it.
Options are as I see it:
Pro Cooler
Improved evaporator unit
Underbelly condensor.
I think the first two are in the ballpark same price, however the last two reqire some hose replacement. Much of the hosing on my car was replaced by the PO. Notwithstanding the hose issue what's the most effective next step?
TIA

None of the above.

Add a fan and condenser in the front left fender. IMHO, the underbelly condenser is only effective when you're moving. Otherwise, the heat from the asphalt is radiating up into the condenser, inhibiting heat transfer. Here's a picture of my condenser set-up in the front left fender:

[PatrickB]

Very nice Scott! What kind of A/C performance improvements were achieved?

[scottb]

Vent temps in the mid-to-high 30s. (ProCooler was installed at the same time as the condenser.)

[PatrickB]

Dumb Question #2 - ProCooler?

[scottb]

www.procooler.com

[PatrickB]

Thanks!

[hoosierdaddy]

I've been told the rcvr/dryer is kind of like an oil filter and should be replaced every 4-6 years . I don't know this for a fact but it would be fairly inexpensive and once it's done thats just one less thing to think about . You can get rcvr/dryers from many local parts stores at a reasonable price .

Hey Buck,

We added a Rennaire evaporator to the previously installed Procooler on an otherwise stock system. Running 134a on an 85 degree day.

[PatrickB]

Unreal Mark!! What refrigerant are you using???
Are you still getting that kind of performance on those lovely September days your city is famous for?? lol

Just curious if you are still looking at that 50 degree difference when you get 95-100 degree temps plus humidity... Come on.. a guy can still have dreams, right?

[nostatic]

rip the entire system out. Ever since I did that, I haven't had a single problem with the AC.

Patrick,
I've had my ankle in a cast for the last 3 months, so haven't driven it(which is frustrating as hell). I do run the car for a while every couple weeks and turn the ac on. Haven't checked the temp, but it's blowing very cold. I'm running 134a.

[PatrickB]

Originally posted by nostatic
rip the entire system out. Ever since I did that, I haven't had a single problem with the AC.

So .... When your engine has problems, you just remove it as well?

[88911coupe]

Forgot to mention I'm using Duracool. I'm going to hook up the hoses and make sure it's full.

[bigchillcar]

buck,
returning to your question...what are your typical driving conditions? if they involve stop and go, battling traffic, i definitely second what scott says about the underbelly condenser - useless without airflow no matter how big. i'm assuming you have the latter-style barrier hoses and that they aren't leaking, otherwise new hoses on older cars are a wise upgrade if they show up as leaky under a dye test. i think a new r/d can be had fairly cheaply from auto parts stores ($40?) i don't know which one you would ask for or for what car since they probably aren't going to be a porsche part..maybe someone else knows. adding a second, fender-mounted condenser seems to get very good reviews. if you have the rear deck condenser, you might also consider adding an electric puller fan to it that you can switch on manually when needed or with a thermoswitch of sorts. beyond that, search the threads under a topic called 'subcooler' started by jim sims, one of our a/c gurus..
ryan

[88911coupe]

The majority of my driving is around town with occasioal highway driving. I've seen the threads on adding the front condensor but it seemed to be a pretty involved process. Maybe I should re read them in more detail. I can probably replace the R/D but was unclear on how big an impact this has on AC performance. I am fairly sure the one on there now it 4-5 years old so maybe it should be replaced...I know others have used a "non Porsche" part very effectively but I don't know what model they actually bought and what sort of modifications had to be made.
Thanks for all the suggestions,

[bigchillcar]

buck,
based upon your reply i'd say you need to focus on gaining more condenser area and with an electric fan. big difference in modern, front-engined, water-cooled cars - they don't have like 30 feet of hose connecting all of their a/c components like we have. they have the luxury of sticking huge condensers right up in front of their radiators and attaching often 2 large puller fans to gain airflow even when sitting in traffic..this kind of luxury isn't easy to engineer into our 911's. r/d's will go bad over enough time and definitely should be replaced anytime you switch refrigerants. there are 'more efficient' condensers which can be considered, jim sims has one in one of his cars. maybe search his threads for info on his..i think he paid $400 for it though. personally, the biggest problem i have is freon leaking out of my old hoses, so that is my priority. next is replacing my very old r/d, then i'm going to stick with my old condenser in rear, but try to gain clearance for a low profile fan..then i'll see where i am.
ryan