Adding Classic Retrofit AC
 

I'm new to this and "while I'm there" syndrome kicked in. Started with upgrading the alternator. To get this done I removed the throttles bodies and completed a heat backdate. While doing this I found all the gas lines had cracks so I replaced those. Which also lead to replacing tunnel gas lines. Followed by chasing speed and reference sensors then a wild goose chase with the oxygen sensor. Finally the distributor cap, rotor and spark wires. Today was the first day I thought I had the car in a position to start on real AC work. I got the fresh air blower and plenum out and found that the 88 3.2 has a different air distribution set up than the SCs that most posts have. So I am trying to figure out which ducts (center, footwell, center lower and sides) to which blower outlet to get the best efficiency out of the blower.
I know that I the new CR condenser requires the front driver's fog light to be removed, so I went all in and bought a SC (fog light delete) front valance. This also gives me a free space on the dash. I'd like to use the fog light pull switch in place of the CR led push button but I need to learn how to rewire the two to work. I also want to see if the old AC knob center picture (snow flake) will fit in the repurposed fog light pull switch (and light up).
Since I removed my center console so I need to find a place for my hazard light button. I'd like it to go in the unused spot to the right of the steering wheel (behind windshield wiper stalk).
I also plan to put a Griffiths Kuehl center condenser in series with the CR condenser.http://forums.pelicanparts.com/uploa...1627909793.jpg
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Great start. I'm not sure of your climate, but 2nd condenser just seems like a no brainer at this point. If my car already had the hole cut out of the frunk for the blower I too would have went the route for the front under belly 2nd condensor.

I just posted a video on my thread that may help with your hose routing. I'm not sure what the side vent ports look like, but if they are 40mm at the body then I would remove that gray branch Y fitting connected to your center vent and just have the 40mm off the blower. There are some recent lower center vent 3d files that were posted by Timmy2. They will be extremely helpful for your setup of utilizing the lower center vent. If you did not purchase the CR foot vents you will want to have some of those printed as well. Good luck!

I really know nothing about the classic retrofit. What year is the body?

The 3.2 Carrera as well as the SC mostly came with factory AC if the car was a USA model. If it was removed, as it looks like your options are many. On my 85 it came from the factory with the front and rear condenser only. That is fine for night driving, or temps below 85 at the most. If you live in an area that sees real heat, you will want more condenser capacity.

I went with the full Griffith's system and now I have 4 condensers. On the hottest of days I can keep my wife and I totally comfortable, and on occasion she requests I turn the temp up because she is cold.

So your first decision is determine how cool do you want to be. Then which vendor you want to go with. After 14 years I simply love my Griffiths system. I live in Oklahoma and drive in hot weather to other states and long road trips. Key West in July, Savannah, GA in August and Needles, California when it was 118 degrees. I remained cool.

Good luck, and welcome to Pelican!

Went with Griffiths the full monty and had it installed.....don't forget to get your windows tinted as it too helps.

Just so some are aware I believe the griffiths full monty is about $5k so similar in comparison to the CR. Also that is comparing 2 condensors to 4.

Mixed bag
 

I have the Classic Retrofit kit single condenser full kit. I just ordered the Griffiths Keuhl front condenser and blower fan to make it a 2 condenser system (my original A/C system was in poor condition). I am trying to obtain the additional connectors to build the hoses to go from the CR condenser to the Griffiths and then to the drier. I also need to study how to tie in the griffiths blower electrical with the CR ECU and power.

I have a bad tint on the back window but will look into replacing that and getting the rest done.

Since Nditiz1 and others did such great jobs on their writeups and inputs I have some confidence, but I would still like to make sure I use the CR blower in the most efficient manner. So I am still trying to figure out which blower outlets should go to which 3.2 vent. The CR provided diagrams and most pelican writeups tend to be for SC or earlier setups.

Thanks Nditiz1, I do think the Porsche original white plastic T should be removed and the center and side vent should each have their own separate supply. I am hoping that Jonny or someone else with 3.2 setup experience will confirm.

Just follow our instructions and use the small outlets (40mm) to the side vents. They are smaller for a reason - to limit the flow to the side vents. This increases the flow to the centre vent which is where you really need it.

This thread is a reason I am having doubt about the CR system. If, with a double condenser set up, I can’t be comfortable on a reasonably long trip why am I spending $5k plus install? Johnny repeatedly gives the same advice. But is it working in real life?. Some of his thoughts are to me, indicative of a system in need of improvement. One weakness is the lower effectiveness of an electric compressor. Well, we may have to live with that if you don’t want an engine driven compressor. But playing with blocking some AC outlets is a crapshoot. Pick your car, experiment to end of your patience, and accept the results good or bad. This does not give me a warm and fuzzy feeling. I’ll say it again, we are beta testing his system. That to me deserves some more accommodation than block a vent.

@Bill - you might be jumping the gun here. I understand your concerns, but from what others like Duc Hunter and Targa80 have posted they are getting the job done with 2. I will have some new numbers and tests when I complete mine hopefully in a week.

Bill5900 - I am sorry if my post was taken wrong but Jonny's response does not say to block off a vent. He was explaining that his system has accommodated the 3.2 setup I just didn't understand it properly since I was also looking at several posts by guys with SCs. I have to give kudos to Jonny, so far every thread I have read with questions he has answered. I admire this when you realize the level of customers he has and he will still respond to some hack like me.

Jonny - Thanks will do.

I know I live in the NW, but with my single condenser system I have been plenty cool on some very hot days (around 100F). Maybe the difference is the very low humidity we have here during summer vs the high humidity in the south where some of the other posters are. I just know I am finding my system to be totally up to the task.

We are fortunate to have two vendors that sell two entirely different AC upgrade systems for our 911’s. The belt driven system has been around for quite a while and I am sure has improved with time based on input from customers who live in different climate environments. The electric system is newer in design and is evolving because of direct input from customers. The original electric system was designed initially for the UK market and they were upfront to stress that results will vary based on your climate environment.

I have been looking at upgrading my non functional stock AC system for about 10 years and I went through the pro and cons with both systems before making a decision. I did want to do the upgrade myself and both system allow that. I will not make any statement than sheds a negative light on either system. It is up to each individual to decide what you want out of the upgrade. I live in the high temp/high humidity summers of Florida so my environment will tax the system more than a car in the North/East/West during the summer months and the system 1st is still required in the dead of winter in Florida. So in the winter months rapidly achieving 40F degree vent temps is no problem and in the summer months reaching below 50F is achievable but takes more time to cool down a heat soaked car with an inside temp close to 100F.

I decided to go with the electric system and I am happy with my decision.

FWIW I also evaluated the belt-driven option before choosing CR. Reasoning boiled down to a few key points:
1) Belt-drive recommended four condensers for my car and location, which I felt seemed like a lot
2) I preferred the independent control of compressor speed with CR, which is a precursor to a future smarter automatic full climate control (same with the R&D project around servo-controlled blend valves)
3) Even though I didn't buy the bigger alternator for now, I see that as an available future upgrade path for added performance
4) I liked being able to keep all the hoses as short as possible by keeping the whole system in the front end of the car
5) I preferred not having more stuff hanging off the engine

Having seen Nditiz1's system in person, in its single-condenser guise, I am confident performance with two condensers will be more than sufficient for my mid-Atlantic summers.

Again, I have no first hand info on the CR system, and I hear it seems to work for many.

I live in Oklahoma and we usually have many days of heat index of 125+, 95 degrees and 90% humidity is not unheard of. Houston is even worse, and Savannah, GA is the winner of hot and humid weather. In the extremes, the full Griffith's system if installed following the fantastic instructions will simply work to keep you cool or even make you cold.

If you live in So Cal, it is likely overkill unless you drive out to Bakersfield, or any of the central cities away from the ocean.

My biggest recent test was returning from Key West, FL. Driving home going due west right into the afternoon sun, 100+ degree day, sunshine on my chest, I had to dial the temperature up as I was was getting cold. My sunglasses fogged up every-time I stopped at a rest stop for a comfort break.

I have yet to install my CR system so I can’t really speak to performance but my criteria for choosing CR were:

-I live in Chicago and while it does get hot here it usually passes in a few days so a multi- condenser might not be totally necessary and if I find that I need a second I can always add it later

- I have a 1977 S and didn’t want anything stressing the engine at all

- my car has a modest engine and weight reduction is the name of the game. The stock non-working AC system I removed was 70# the CR is half of that and the weight is in the front not rear

- tech: CR is innovating new products to go around this system and constantly updating the firmware which is something important to me- I want a product that has room to improve and a company that is actively doing so.

Guys-
I love hearing the pros and cons of the systems because I am still installing what I have already purchased and the comments do help me make adjustments to the install, keep them coming....but I am still looking for specifics (parts and how) for: 1. New hose fittings to connect the Griffiths Keuhl condenser in series with the CR electric system. 2. Whether to use the #6 hose or #8 hose between the CR supplied condenser and the Griffiths then I believe it is #6 to the drier from the Griffiths. 3. How to connect the electrical of the Porsche frunk front condenser blower to the CR system for control of it and power for it. Thanks again.

The following may help you in how to connect a second condenser fan using the existing AC relay and wiring.

Attached are three pics:

1. The changes I made to the AC electrical schematic.
2. The four pin white to black connector, I removed all of the wires except the green wire from the white connector.
3. The green wire from the white 4 pin connector was cut and spliced to the white wire from the CR black 4 pin relay.


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I appreciate the comments. Yes, Johnny has been helping a lot with the installations that have threads here. Apparently behind the scenes quite a bit. But his Herculean efforts show the system needs a lot of tweaking. I am awaiting my kit and have become more comfortable about putting the black box blower in my SWB. I will say, however, there are two options that need consideration at least until some better controls of the system are present. Firstly, if you aren’t running entirely recirc you are not getting optimum performance from the system. If you have blender boxes I think you can hedge that in your initial installation. The next is the so-called balance of the system. I take it from Johnny’s comments that it is fixed inside that black box.. Well people are putting vents in different places, most I think also in the footwell (the purpose of that I still don’t understand—if you have strong recirc down there cold air will find the foot wells) So I will not be using all the blower outlets as to each having a vent. If they can’t be blocked because the black box doesn’t like it, then two may be combined to go to one vent. I admire the tenacity of the installers; I hope you soon see the results that make you comfortable’!

I did find this to replace the bow tie vent right in front of the shifter below the ashtray. It fits perfectly in the hole.
https://www.aircraftspruce.com/catalog/appages/plasticeyeball1.php

With any air system, the air will take the path of least resistance. As soon as you add ductwork, you are adding resistance. When OEMs design blower units they balance the flow by partially blocking or sizing certain ducts but usually the blower and ducting arrangement is the same for a particular car model.

Because there are SO many variations of the Porsche 911 duct work spanning 26 years (I can think of at least 12) it is impossible to have a one size fits all solution.

Porsche had the same issue with the fresh air blower which is why you find partially blocked off parts in the original system. E.g look inside the screen vents on an SC and you will find a half moon block off. That’s because the SC has centre vents and they needed more flow.

We suggest an air flow scheme that we have tried and tested in our manual but these Porsche cats won’t be herded. :) Most of the guys on here are adding extra ducts or have gone ‘off piste’, hence the debating.

If the system is installed as per the manual, it works. Change the config and YMMV.

Jonny, have you had many 3.2 folks do this system?

If so, did those people ditch the rear compressor and decklid condenser?

Still a ways off from doing anything like this to my own car, but to me if this system allows me to ditch that stuff, that's a real advantage. Also like that it brings a little sanity to the wonky stock AC/fresh air situation.

Thought I’d add my what I think is the install plumbing for the front Porsche condenser in series with the Front CR. Also is my guess of the rear 2nd condenser from CR. I searched and could not find a drawing on CR web. Hope CR doesn’t mind my use of their drawings.

http://forums.pelicanparts.com/uploa...1630505140.jpg

Would be nice to know if these are the appropriate install method for a second condenser prior to spending 7k or more. Also, I assume if one wanted a third a combination of these two would be fine?

If this intrudes in anyway, I’m happy to remove this and start a new thread.

Been asking CR about the “just ask 6 mm fittings” mentioned by Johnny H in Targa80’s install thread. No reply from them yet … hum … received email today 9/1/21, CR says the fittings are not on the website but are in stock “ If you place an order through the webshop for 2 x Pad fitting E's ( they are the same price ) and just add a note to change them to standard belly pan fittings”.

Mike back So more money, no problem there!

Both drawings work for me, the second drawing is how I added the OEM condenser. I guess you could merge both drawings to create a three condenser system.

Was pretty sure, but thought I’d draw it for my own benefit, thanks for confirming.

FWIW, I’m creating an excel spreadsheet, attempting to document where to find all the good stuff:

E.G., Targa80’s fan wiring, the needed lap top driver to communicate, top of blower can be adjusted, Targa80 drain hose fixes … boden cable tips

Need to find how much extra oil to add, and how much R134 with two condensers to the sheet. Will add sheet to my thread once I start it. Also should add orientation for Freon hose for blower (towards gauges) so lesson interference with brake booster vac connection. Not sure about adding in-line blower found (Turbo), seems it can easily be added and discarded if not liked.

Closer to getting the AC as time goes on.

2 condensers is 650 grams. It is found in the 964/993 documentation.

EDIT* - It has been said numerous times that the 2nd condensor should follow the CR condenser so it would be #6 line to the rear and then to the drier. Th goof thing I found was that I had my #6 coming out the bottom (front of the car) CR condenser and there was enough length to reach the rear condenser when removing it from the front and sending it to the back.

Maybe, then I wonder why is the connection on the CR web is a number 8 E pad with two of these used ,$34.41 each, to add a second (third too I’ll assume) condenser to an AC system. Confused I are ;)

If you don’t mind, who has said this numerous times? Want to look further. Seems the second rear condenser could be attached to number 8 line to me. All outputs go through the dryer to get to compressor

I find the lack of a refrigerant line plumbing documentation, for the “two condenser CR system they sell”, to be conspicuous by its absence.

Sorry for the confusion there. You are right it is pad fitting E is #8. I was referring to the size of the line which is #6 - 5/16. That is the smaller line. In your first drawing you have it coming out of fitting D.

Well, excuse my need to clarify my rear condenser drawing:

I removed my rear condenser drawing which is OBE via the 993 dual condenser drawing mentioned by Johnny.

^. There is twin condenser diagram in the 964/993 manual.

Primary condenser has #8 D fitting on input and #6 E fitting on output.

Second condensers always use the smaller #6 E fitting on both ports.

Must get round to adding it to the 911 manual.

Thanks, this helps.
And Jonny H,

The compressor and evap etc of this system can cope with three condensers, correct?

Thanks Nditiz1 and Pat (Targa80) for all your posts! and thanks Jonny for giving us the help! I got side tracked with several other items (cracked heat exchanger with broken studs, fitting an older front valance instead of cutting my fog light bracket, and trying to figure out how to fit older sport seats that don't have a seat belt receiver attachment point). The last two nights I worked on the ECU/compressor carriage assembly. Should have been easy but since it took me so long to start working on mine I had to create a bracket for the updated relay CR is now shipping as standard. Like others have documented the original ECU plate does not have the correct attachment point so I learned how to use a tap and thread some holes in a new attachment plate. I also got a package of 60mm 90 bends that fit on the T's CR sends out. I'm hoping they help get tighter bends on the ducting I am using. I am trying some CEET duct from Aircraft Spruce so that it will have a smooth lining and maybe cut down on condensation since it is thicker rubber walls. But I learned the radius at the bends were not conducive to the tight space.
I think they might allow me to use the 60mm duct on the drivers side of the blower to supply my driver side vent. I hope this doesn't screw up Jonny's airflow plan. Then I can use the 40mm duct (driver's side) to supply my new eye ball vent that is replacing the bow tie. Hopefully this weekend I can at least have fresh air fan system worked out, and be well on my way with the refrigerant line set up. Car has to be in driving order by Weds so I we can drive it to Luft.http://forums.pelicanparts.com/uploa...1630638200.jpg
http://forums.pelicanparts.com/uploa...1630638200.jpg

Pat /NDitiz1, did either of you add additional PAG oil for your front condenser? Or just add more R134 (650 grams) for the increased volume of the system with the additional condenser?

Perhaps someone can clear up my confusion. Seems to me, the front condenser on a front / rear arrangement is best hooked to the drier. That way it can be the last to subcool and make up any losses in the long line from the rear condenser, as well as have a short line to the blower. Is that what we are talking about? Also, the condensers on the CR system appear to be the same size as Porsche’s condensers, albeit with micro channel and maybe other updates. It still seems to me that two should be sufficient for the CR system in most climates. Anybody out there, using more? Thanks.

Bill5900 sorry I can't give you any details, I am mimicking Pat (Targa80) by putting going from the compressor to the CR condenser in the driver front wheel well, then to a condenser in the original Porsche position in the center behind the front bumper then to the drier. I did get a Griffiths "high efficiency" front condenser and fan.

I did add a very little bit of PAG oil to the system with no knowledge of how much I should add. In essence, I added about 1/4 of a shot glass of PAG oil thinking it would not be to much and hopefully not to little.

While there... I learned I have a intensive windshield washer in my car. Since I do not use the washer that much I am wondering if I can forgo the main washer and just use regular fluid in the "Intensive Washer" to use it as my primary. I think it would just mean that I have to use the button/switch to activate it and would also help to keep from those accidental sprays when I unintentionally hit the windshield washer stalk. Down side I would have a reservoir of water in my frunk.http://forums.pelicanparts.com/uploa...1630702302.jpg

I had to come in to check on part deliveries so I am taking a break on installation. Here is how the 90 degree bend tubes are helping me out with the limited space on the driver side. I was able to put one of them in the firewall hole that goes to the driver side vent which gave me a sharper turn radius for the 60mm CEET tube. I also attached one to the T coming from the footwell. I think they are perfect on the T since they give you a very clean bend, they are smooth inside, and the lock in to the T and swivel.


http://forums.pelicanparts.com/uploa...1630702702.jpg

Pelican Uwon uses his intensive bottle exclusively I think.
So you might ask him.

See post #4 here
http://forums.pelicanparts.com/porsche-911-technical-forum/1101017-removing-oem-c-parts-upgrade.html

thanks Mike! Forgot the first rule, search....then ask!