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Originally Posted by GH85Carrera View Post
The big difference is most other cars have all the AC components in the engine compartment, and all close together. With the 27 feet of hoses, and 4 condensers, evaporator, and other various parts, water (ice) has a lot of places to hide.

It is physically impossible to have to good of a vacuum. And water will freeze into ice and "hide" in the system in a typical 10 minute vacuum pull.

At least one nitrogen purge is a very wise move. Just my opinion, and I am not an AC pro, just a dude with some kick butt AC in my 85 911.
No AC expert here either, just someone who likes to delve into the technical car stuff but I do this on the DD.

About the evacuation part of the process, Porsche manual says at least half hour, which is on par with other systems ... of course with an industrial machine, a Robinair of that era for R12. I'm guessing modern systems are equivalent or likely better.

I would think how good a vacuum you end up with is more a matter of how much negative pressure your machine can generate rather than how long it is left on beyond an initial drawdown.
Second, our OP's system is new so there shouldn't be much leftover moisture in there.

Would be great if our pro can chime in.

Quote:
...

...
I was 100% comfortable in my car on a toasty day in southern New Mexico. After an hour of driving, I have to turn the temp up and the fan down to avoid getting cold unless I am driving due west with the sun shining directly on me.
Nice but I can't recall having seen any pics of the rest of your installed system.


Last edited by pmax; 03-27-2025 at 10:49 AM..
Old 03-27-2025, 10:45 AM
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The Porsche manual was for the line mechanic and what he would get paid to do, on a 100% stock system. Add in a bigger front condenser, improved evaporator, two new condensers that were not in the original car, and lots more hose and you can understand the issue.

And a brand new system is open to the atmosphere during installation. Unless he lives is death valley with single digit humidity, air and thus air moisture got in to every component. That is why every competent pro suggests replacing the receiver-dryer if the system is opened to atmosphere.

I put my Griffith's system in 18 years ago back before smart phones. I have some photos of the installation, but they are buried on a backup somewhere.

Also, I upgraded to the hurricane blower later, and I added his variable speed control and temp control at a later date.



This is a photo of what NOT to do. The giant nut on the return to the compressor is super easy to over torque. Using a large wrench to tighten that 27mm nut (I think) is very easy to snug it down just a bit too much.


Here is a photo of the engine just after a new alternator, and fresh ceracoated fan and housing. It was my most recent project on my 911.
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Old 03-27-2025, 01:16 PM
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Originally Posted by GH85Carrera View Post
The Porsche manual was for the line mechanic and what he would get paid to do, on a 100% stock system. Add in a bigger front condenser, improved evaporator, two new condensers that were not in the original car, and lots more hose and you can understand the issue.

And a brand new system is open to the atmosphere during installation. Unless he lives is death valley with single digit humidity, air and thus air moisture got in to every component.
Does Griffith recommend any specific evacuation process other than what any competent AC pro shop should know ?

Quote:
That is why every competent pro suggests replacing the receiver-dryer if the system is opened to atmosphere.
The receiver-dryer is a consumable so I would think it should be replaced regularly regardless of whether the system is opened to atmosphere or not. Likewise, you wouldn't have to replace a 90% efficient receiver-dryer just because the system is opened other than for the "while you're in there" reason given the cost already incurred.

Quote:
I put my Griffith's system in 18 years ago back before smart phones. I have some photos of the installation, but they are buried on a backup somewhere.

Also, I upgraded to the hurricane blower later, and I added his variable speed control and temp control at a later date.



This is a photo of what NOT to do. The giant nut on the return to the compressor is super easy to over torque. Using a large wrench to tighten that 27mm nut (I think) is very easy to snug it down just a bit too much.
Yes, those O-rings do not take much torque... if I recall, the nuts don't even need to be "tight" by normal standards, I forget the exact torque spec but I did use a torque wrench on those while changing them out on my DD.

Quote:

Here is a photo of the engine just after a new alternator, and fresh ceracoated fan and housing. It was my most recent project on my 911.
Current photos of your installed system would do
Old 03-27-2025, 02:55 PM
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Originally Posted by pmax View Post
Does Griffith recommend any specific evacuation process other than what any competent AC pro shop should know ?
The instructions indicate doing a 1/2 hour vacuum pull, wait 1/2 hour, see if holding. repeat until it is good.

Then do a Refrigerant or Nitrogen purge while under vacuum, repeat.

Then pull vacuum for 2 hours, check after 15 minutes - if dropping, fix leaks, repeat.

Then charge.

Quote:


Yes, those O-rings do not take much torque... if I recall, the nuts don't even need to be "tight" by normal standards, I forget the exact torque spec but I did use a torque wrench on those while changing them out on my DD.
Griff indicates 10-14 Ft-lbs... so not much really. I tried to be super careful to not squeeze the orings by too much. - especially as mentioned, the big 27mm - that is a long wrench and easy to apply too much pressure.
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Old 03-27-2025, 03:29 PM
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Quote:
Originally Posted by pmax View Post
Does Griffith recommend any specific evacuation process other than what any competent AC pro shop should know ?



The receiver-dryer is a consumable so I would think it should be replaced regularly regardless of whether the system is opened to atmosphere or not. Likewise, you wouldn't have to replace a 90% efficient receiver-dryer just because the system is opened other than for the "while you're in there" reason given the cost already incurred.



Yes, those O-rings do not take much torque... if I recall, the nuts don't even need to be "tight" by normal standards, I forget the exact torque spec but I did use a torque wrench on those while changing them out on my DD.



Current photos of your installed system would do
What photos are you interested in? The evaporator box will look pretty much OEM, except the new relay Griff supplies. My front condenser is OEM, and unchanged, as is the rear engine compartment condenser. Next time I have it in the air, I can photograph the front and rear fender condensers, but they look like the ones in the thread, only mine are relly dirty from 75,000 plus miles since installation. I do have the center vent on top of the console, and the two under dash vents.


This is a shot from replacing the shifter bushings, and repairing the leather gator which required removing the original shift knob, and I had to destroy that knob. You can see Griffith's controller in the passenger footwell.


Getting the switches back in place is no fun either. This was before the new push on connectors went on.


This shows the knee vents on one side. I was working on the instruments, and removing the steering wheel is super easy.
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Last edited by GH85Carrera; 03-27-2025 at 06:53 PM..
Old 03-27-2025, 06:50 PM
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Originally Posted by GH85Carrera View Post
What photos are you interested in? The evaporator box will look pretty much OEM, except the new relay Griff supplies.
Thanks ... anything is fine ... that is if ccallana doesn't mind ... but it would be interesting to compare how another install differs if any in terms of the routing, wiring etc. Are the evaporator and expansion valve, console surgery must do items ?

Quote:
Originally Posted by ccallana View Post
The instructions indicate doing a 1/2 hour vacuum pull, wait 1/2 hour, see if holding. repeat until it is good.

Then do a Refrigerant or Nitrogen purge while under vacuum, repeat.

Then pull vacuum for 2 hours, check after 15 minutes - if dropping, fix leaks, repeat.

Then charge.
Yep, I certainly didn't do all that on the DD but then again, I only have a DIY setup not the $K pro machines which I assume the above calls for.

Quote:
Griff indicates 10-14 Ft-lbs... so not much really. I tried to be super careful to not squeeze the orings by too much. - especially as mentioned, the big 27mm - that is a long wrench and easy to apply too much pressure.
Incidentally, the Porsche manual indicates a higher 21-27 for the suction port, evaporator intake , 14-20 on the pressure port of the compressor, rear condenser, 10-14 on the rest but these are for the R12 versions of course.

Last edited by pmax; 03-28-2025 at 01:29 PM..
Old 03-28-2025, 01:25 PM
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I have no clue on how other installations differ. Way back in 2006 I started asking around, fellow PCA members, and doing some online research. Part of that is what brought me to Pelican.

I heard time and again, Griffith's is not the cheapest, but it is hard to believe anything would be higher quality. I suspect ccallana would agree, as each component is unboxed and examined, the thoughts of dang, that is nice engineering and quality. And the instructions are super clear, and over and over you will think, man he sure thought the installation out, and that is clever! Charlie is wonderful tech support with a phone call or email.

Bottom line for me was wanting AC that just simply worked. In August, in Savannah, GA my wife said she was cold, and wanted me to turn the temp up! I almost got out and did a happy dance around the 911. The heat index hit 135 one day that week, and was way into triple digits every day.

If someone living in an area with mid summers, it might be overkill. The factory system when working at peak performance is fine at night, or in the rain. It is useless on a hot day in full sun. I was sick of shameful AC performance, and my wife would not ride with me until something was done. She suggested I (gasp) sell my 911, and get a new or newer Porsche. Not gonna happen. After 30 years of ownership, I love it even more.
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Old 03-28-2025, 02:51 PM
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Absolutely the highest quality stuff and the best packaging I have ever seen. Solid boxes, stapled and taped. (As a side note, FCP Euro has the worst packaging I have ever seen .. 4 times now I have ordered oil from them, Motul in 2L cans... All three times the cans have come dented and smashed. )

I live in Sacramento... Not quite Phoenix weather, but long stretches of really hot days .. like Glen, I wanted something that just works .. I considered the Classic Retro electric system, but besides the significant extra cost, it seemed like it doesn't work quite as well as Griffiths... At least by the anecdotal evidence I found. My wife doesn't entirely enjoy riding around in the 911 as it is, so one less excuse is a really good thing.
Old 03-28-2025, 05:01 PM
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Originally Posted by GH85Carrera View Post
I have no clue on how other installations differ. Way back in 2006 I started asking around, fellow PCA members, and doing some online research. Part of that is what brought me to Pelican.
...
You did offer

Quote:
I heard time and again, Griffith's is not the cheapest, but it is hard to believe anything would be higher quality.
...
... but I get it.

Never mind then.
Old 03-28-2025, 11:03 PM
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Did a vacuum check at home with a rented pump from the parts store - seemed to be holding, so booked an appt with an A/C shop -
bummer part was of course this week is not that warm - in fact drove it there in the rain yesterday -

He did an N2 pressure check, found a couple messed up o-rings - but after fixing those, held 200 PSI for over an hour. Did 2 hour long vacuum checks.. charged it up... and its blowing cold...

Air temp is only 60 though... he asked me to come back when the weather is warmer, and he'll recheck everything, see if anything needs to be tweaked...

it blew pretty cold coming home - but not really fair given it isn't warm outside...we'll see in a few weeks!
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Old 04-02-2025, 03:22 PM
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That should be a good enough purge and vacuum to get you good performance.

One recent mission to the moon by India is finding more ice on the moon that expected. The vacuum in space is way better of a vacuum than you can get with any equipment on a car. Yet there is ice that is on the moon in a virtual perfect vacuum that has been there for unknown millions of years.

As I have mention before, it is physically impossible to get to good of a vacuum in your AC system. Less is better.
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Old 04-03-2025, 05:34 AM
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fwiw i was able to get the strap around the washer fluid reservoir back in using tie-wraps to pull the sides together and an awl to keep the backplate oriented properly so I could get the screw started. It is a real PITA.
Old 04-07-2025, 06:24 AM
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fwiw i was able to get the strap around the washer fluid reservoir back in using tie-wraps to pull the sides together and an awl to keep the backplate oriented properly so I could get the screw started. It is a real PITA.

The easy way I’d buy a longer bolt!
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Old 04-07-2025, 12:16 PM
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The easy way I’d buy a longer bolt!

Yup - exactly I should just take the thing out and just use the "intensive" washer... save space, weight, hassle.....

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Old 04-07-2025, 12:24 PM
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