Mike: You have mail.

Mid summer check in. Doing so because of alot of A/C threads leave me wanting more in terms of follow-up after the project is completed. How's it doing?

91 degrees here yesterday and partly cloudy on the commute home yesterday. At 3 o'clock temp dial setting I got steady vent temps of 43 degrees with fan at full speed and 38 degrees at med speed. Pretty good - no complaints. If it had been sunny cabin greenhouse effect would have increased vent temps by about 5 degrees. My shirt was completely dry after 45 minute commute and the passenger seat was cool to the touch.

If I run the temp dial at full cool for an extended period of time at high ambient and humidity conditions the evap tends to freeze up. If I run it at the 3 - 5 o'clock position on the dial, no freeze ups/reduced air flow at the vents.

At really high ambients in stop and go traffic after car is heat soaked (e.g. lunch trips) the system still performs good but vent temps are clearly higher (high 40's or low 50's) until I can get the rpm's and air flow up.

Very few days this summer with a wet shirt back - really only when car is heat soaked at lunch - I don't care how well your A/C is working, if you sit on 100 degree leather seats you're going to sweat.

Possible tweaks? Wondering if changing out my rear deck lid condenser from OEM tube and fin unit to a high efficiency serpentine unit would help on the mid-day extreme conditions. Also wondering if I could drop the rear deck condenser down 1/2 to 3/4" via spacers to maker room for larger fans above the condenser to create more air flow over more area. vs. this set up where I've got fans covering about 1/2 of the condenser:


http://forums.pelicanparts.com/uploa...1217935310.jpg

Mark,
Based on your history of temps I'd suggest focusing on the thermostat ;)

I like that fan setup on the rear condenser. Does anyone have "upgrade" ideas for the airmover on the front condenser? Is there anything to gain with better airflow up there? Could be less expensive than a new condenser but would likely require some custom work.

I have the complete $1450 R134 Rennaire kit installed and I have a top quality robinaire vacuum pump and mastercool gauges and I know how to use them.

I couldn't get vent temps below the mid 40's with the fan on high in my venetian blue '87 turbo on a sunny humid day in the mid 90's here in south florida.
I bought this big serpentine fenderwell condensor with the 10" fan included that goes in front of the left rear tire at a slight angle to fit and it made alllll the difference. You couldn't fit a bigger condensor in there...
http://www.***********/cgi/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2eallzim%2eco m%2facatalog%2f&WD=conditioner%20air&PN=911_COOL_K it%2ehtml%23a911_2e573_2eADD_2eCOOL#a911_2e573_2eA DD_2eCOOL
Incredible difference.

Now I have low thirties out of the vents with the fan on high.
Feels really good when the heat and humidity south florida sauna effect feels like 105 degrees outside.

In front of the left rear tire? Can you post pictures of the installation?

Thanks!

From the information that I have gather up it seems that when you get a more efficient engine lid condenser it will exchange more heat which has to flow over the engine, thus that can raise the oil temperature. So you might improve the A/C, but at the expensive of the oil temp.

I'm with "hocoles", I think the next step beyond what's already out there is the front condenser fan motor. If we have upgraded evaporator fan motors why not a upgraded condenser fan motor...

I'm close to re-charging my system after installing a Rennaire evaporator and ProCooler from our host, and a Retroaire upgraded blower motor. If it works out I'll do a follow up on it.

Could it be that my thermostat is bad? The end of the capillary tube wire that fits into the copper sleeve is a little chewed up/ corroded on the end - it actually comes to a point more or less. Wondering if I should just go ahead and replace it so I'll know its functioning properly???

installed pic
 

My car happens to be on jackstands with the rear wheels removed for other reasons right now so I just went out and took a pic of it.

I have 18x11" 996TT wheels with 315/30x18 tires on the back and there is still 2" of clearence from the tire when the car is on the ground... no problem.

It's a really well fabricated kit with an aluminum debris/splash guard and everything including the correct length mounting screws and a barrier hose to go to the rear deck lid condensor that I didn't use comes with the kit.
Instead I spliced into the 19.5' long high pressure barrier hose using the supplied fittings in the kit, into the Rennaire hose that I already had installed.
I used two wide all stainless USA made name brand hose clamps and tightened them real tight on each fitting for peace of mind and less chance of R134 leakage.
Professionally made crimped on fittings on custom length hoses is better but this was way cheaper and it's not leaking

It's hard to see from the flash glare but there are 3 self tapping sheet metal screws in the top right corner of the aluminum splash gaurd mounting it to the fender well.
The screws are short so they don't go through the leather interior in that spot!

I have weltmeister adjustable spring plates that you can see so I don't have to remove the condensor to adjust ride height or corner balance the car.

You can also see by looking at all 4 corners of this 18"x12.5" condensor that a bigger one wouldn't fit.
Thats a 10" puller fan on there that comes with a fused relay in the kit.

Gee... I'm starting to sound like a sales rep, but I'm not, I just wannt to help out using my experience so I'm gonna shut up now...http://forums.pelicanparts.com/uploa...1217949831.jpg

Has anyone purchased AC tools from viot.us? I need to stock up to finish my project with pretty much everything (gauge set, v-pump at a minimum).

Mark

You might want to consider adding test ports on the suction and discharge lines at the compressor. A friend of mine just finished a similar installation on his 77 911. The test ports on the compressor did not give him good readings after he had charged the system. When he questioned the compressor seller they said they would not rely on the ports at the compressor, better to install ones on the hoses.

Steve Sanders
86-911 cab

I'm a little leery about he price of the Griffiths serpentine evaporator, but was reading this thread and wondered about the benefits of converting to a R-134a expansion valve instead of the original R-12 one. Is it worth it? I'm not getting very cold temps, about 50 at the vent when it's 85 out and I'm doing 60 mph.

Where can I look at the three fans on the rear condensor? Thanks

sub

You won't gain much, however to start what is the superheat of the two valves you are comparing.

My source for the fans here:

http://www.the-fan-man.com/

My install thread here:

http://forums.pelicanparts.com/porsche-911-technical-forum/312760-adding-3-fans-rear-c-condenser.html?highlight=adding+fans

I made a heat shield between the cat and that condensor. I made it with two heavy duty aluminum baking tins from Smart and Final and I filled them with fiberglass insulation and stapled them together, they work great about a 2$ fix so the condensor doesn't "see" the heat from the cat. After a 100 mile drive, it's cool to the touch, leave an air gap.

haven't got a clue. The one in the car is for an aftermarket R-12 system but an OEM Porsche evaporator. When going through the system years ago, I believe I took the valve apart to "clean, check, whatever" and just screwed it back together, with no thought to whether it needed to be "adjusted" for superheat, which I don't totally understand. I guess my question is whether an expansion valve designed for R-134a would give better cooling. Oh, and your system looks fabulous, but out of my price range to experiment at this time. I may well buy your new and improved evaporator blower fan, THAT I'm pretty sure will go a long way towards improvements.

Yes a new expansion valve for R134 would cool the car better.
If you buy a new generic one thats all you will get, unless you buy a more expensive OEM R12 one from a porsche dealer.

R134 molecules are smaller than R12 molecules, so the orifice adjustment in the expansion valve should be a little smaller for R134.

I've heard of people succesfully turning the allenhead superheat adjustment in the origonal R12 expansion valve inwards 1-1.5 turns when converting to R134.

Quality aftermarket expansion valves are only around $30 so I'd just put in a new one made for R134 to be confident of the correct superheat setting and how well it's going to work.

Thanks, that is kind of what I thought. I'm sure mine is way off of its proper setting anyway, because I fiddled with it and turned the allen head inside not knowing that I wasn't supposed to futz with it.