AC Rebuild Question

[Skip1]

After "fixing" most of what I believe requires repair, I'm now looking at costs / level of effort associated with an AC rebuild. All parts, from teh front condensor, blowers, switches and lines etc are in place, less the rear deck lid evaporator and compressor, removed by PO. I have done research on aftermarket near complete replacements, but I'm wondering whether I could salvage / confirm life in the parts of the system I do have, and simply replace the evaporator and new compressor for R134 to get this thing up and running. I have noted many threads talking about the uselessness of the factory AC, so am wondering which direction to go. Temperatures here in the summer are not bad, and I can take the top off, but sometimes its nice to just crank the AC and not stick to that sexy vinyl.

I intend to post some pictures of my current pieces in the next few days if that would be of any use.

Any recommendations / options?

Cheers.

[Scott R]

personally, don't bother with any of the factory stuff it's just a money pit. Get the Rennaire or Griffiths kit that our host sells and start new. I'm installing one currently and it's very easy and in the end I'll have modern AC. I got tired of fixing one leak only to get another a few weeks later on the old system.

[Skip1]

Would you recommend one over the other?

Are they complete systems, including tubes etc, or would one need additional parts?

I assume they are a plug and play type replacement?

[Scott R]

Originally Posted by Skip1

Would you recommend one over the other?

Are they complete systems, including tubes etc, or would one need additional parts?

I assume they are a plug and play type replacement?

They are complete, hoses, condenser, evaporator, compressor. I can't recommend one over the other, I purchased the Rennaire kit however the people from Griffiths are on this board and post diligently when people need support on their products. Thats great for the DIY'er IMO.

[T77911S]

at this point you might as well go with one of the above.

you donty know the condition of the evaporator(up front) (the rear one is the condensor) plus, if it is good, how long will it last and they are a common source for leaks. you have to buy anoother condensor and compressor anyway, and a new dryer and expasion valve is a given, so all you are out is the hoses and evap.
do it right, do it once and be done with it. but thats easy for me to say, its not my $$

[GH85Carrera]

The Griffiths system is top quality stuff. Griff will patiently answer any of your question. His instruction are the most complete of any instructions you will ever read.

I have been very happy with his system for many years.

[SilberUrS6]

Originally Posted by T77911S

at this point you might as well go with one of the above.

you donty know the condition of the evaporator(up front) (the rear one is the condensor) plus, if it is good, how long will it last and they are a common source for leaks. you have to buy anoother condensor and compressor anyway, and a new dryer and expasion valve is a given, so all you are out is the hoses and evap.
do it right, do it once and be done with it. but thats easy for me to say, its not my $$

But if it were your money, you'd say the same thing. Most of us have figured out that some of the most expensive set-ups are the bargain ones - ones you have to go back and fix all the half-assed corner-cutting that went on to make it a bargain in the first place.

That's why the Griffiths stuff costs. Because if it didn't work, work right the first time, and be well-supported and documented from the beginning, they wouldn't sell much product.

[Barrpete]

Both Griffith's and Rennaire have quality systems that work, although they take slightly different approaches. I think Griffith's has better tech support and clearer instructions though.

I installed the Rennaire system with R134a about 4 years ago and it works great in Tucson temps. The one thing I regret not doing is upgrading the evaporator fan because shortly after I finished the install it starting making noise on all but the highest speed. I'm living with it for now but have my eye on Griffith's evap fan upgrade.

[Skip1]

Wow that's a lot of great info in a short time. I was hoping that "replacing the entire system" wouldn't be necessary, but I agree that that probably makes the most sense in the end. Time to start the costing phase.

Thanks for all the great comments and recommendations.

[mthomas58]

Originally Posted by Scott R

personally, don't bother with any of the factory stuff it's just a money pit. Get the Rennaire or Griffiths kit that our host sells and start new. I'm installing one currently and it's very easy and in the end I'll have modern AC. I got tired of fixing one leak only to get another a few weeks later on the old system.

You won't really have "modern AC". You'll have newer more efficient components in a system that remains woefully underengineered, but its the best that can be done for our cars. I'm just sayin!

I second the recommendation against sinking money into factory components.
You need (1) more condenser area (i.e. condenser add-ons), (2) a more efficient undersized serpentine evaporator, (3) barrier hoses that won't leak and (4) more air flow through the evaporator (evap motor upgrade)

[mthomas58]

Originally Posted by Barrpete

Both Griffith's and Rennaire have quality systems that work, although they take slightly different approaches. I think Griffith's has better tech support and clearer instructions though.

I installed the Rennaire system with R134a about 4 years ago and it works great in Tucson temps. The one thing I regret not doing is upgrading the evaporator fan because shortly after I finished the install it starting making noise on all but the highest speed. I'm living with it for now but have my eye on Griffith's evap fan upgrade.

And you won't find better after-the-sale technical support than Griff provides anywhere!

Pull the trigger - the evap motor upgrade is unbelievable! Get yer werblesturm on.

[mthomas58]

Originally Posted by T77911S

.....do it right, do it once and be done with it. but thats easy for me to say, its not my $$.....

Good advice. Wish I would have followed it. I threw $1,900 at the factory system before coming to my senses, admitting defeat, and going with a new system from Griff.

[Jim727]

I guess I swam slightly against the tide. My car is a '71 which had no factory air. Having a bit of a fetish about keeping the spirit of the time, I went to a dismantler (EASY in Emeryville, CA) and pulled everything factory out of a '75 - from the wiring looms and front condenser to the compressor mount. From inside the car, you'd have to really know the details of the year to recognize the under-dash unit as non-stock.

FFwd to about 3 years ago, it's time to upgrade the a/c. Decided to stay with R-12 because, though spendy, it's a better refrigerant than 134 - now there's FR-12, so that decision appears to have been good. Replaced all the hoses with barrier hoses (essential). I pulled the evaporator box - once the system is charged, don't want to have to access that - replaced the fan motor and did a full cleanup. The evaporator is tube/fin, and I wanted serpentine. After a lot of comparing, I got Griff's evaporator - it's serpentine and appears to be about 20% larger in evaporator volume than the stock evaporator through some very creative design work. The piece is a work of art and it's a shame it has to be locked away in the evap box. I also added Griff's variable speed fan controller. Do it! The factory controller has 3 speeds - nothing, almost nothing, and hurricane. The variable speed controller has made the a/c far, far more enjoyable to use.

From Rennaire I got the procooler. Some say it's controversial; I say it's essential. Think I used their barrier hose kit as well. Had a Sanden SD-507 on the shelf awaiting time and money for the upgrade, so that went into the car. I also did some wiring upgrades to ensure that everything was on relays and swapped the smuggler's box relay for one that has the integral fuse (Pelican has those).

So, my system is a hybrid of Griffith and Rennair. The only thing I would do differently perhaps is to go to all serpentine condensers. Even as it is, however, it looks factory and works spectacularly well. I'm very pleased with it.

[Skip1]

So I've looked at both systems now. The only thing I can seem to find is the rear deck lid evaporator for RennAire - does it use the stock one or a Griffith's version?

[Scott R]

Rennaire uses the stock rear deck lid, Griffiths has one you can install in the rear fender like the later cars.

[Skip1]

Oh, ok. Saw those on their site. The rear evaporator is one of two pieces I'm missing in my factory setup - that, and the compressor. Will have to look at all the pieces and see what I'd like to do. I do like the procooler concept. Based on some comments it appears that the two systems can be integrated to some degree - would the connections / hoses etc be compatible or could I run into issues connecting the wheel well evaporator to RennAire hoses for example?

[howard freeman]

Charlie Griffiths systems work very well,even down here in the summer. The tech support is excellent . I have upgraded countless #'s of my clients cars with his systems. The only comments I get from them is they have to turn the A/C down now ,because it to cold.
Howard

[Skip1]

I don't think I'd EVER complain about too cold in my part of the world...

[KelogGes]

Originally Posted by Skip1

So I've looked at both systems now. The only thing I can seem to find is the rear deck lid evaporator for RennAire - does it use the stock one or a Griffith's version?

Porsche 911 A/C CONDENSER Efficiency! IS the best key to making COLD A/C!

Everything Else is secondary !!!

“With More Than All Due Respect to Griffiths & their serpentine technology, and Rennair's products”

I am on a different path, exclusively making PFC’s and other newer technologies for 911’s A/C components

I disagree In terms of a higher performance using older serpentine technology versus using parallel flow micro-channel condensers (PFC) after over a year of exclusively testing using a range of PFC technologies. You are welcome to stop by here and add to your research to making your 911 cold > I make Parallel Flow Micro-Channel Condensers for 911's front and rear

I have also done a lot 911 evaporator testing using Renair's serpentine evaporator compared to using an original old 911 1975 Behr stock evaporator with R-134A & "A Modified (TX) Thermal Expansion Valve" in the south Florida hottest summer months during last years record temps and the air-vent output difference although was slightly improved was not as much of a dramatic difference you might expect or I had expected the difference to be. I also have done test differences of Griffiths serpentine evap. Scientific data comparisons I have read say there is about a 9% at best difference between serpentine & any 911 tube and fin heat exchanger technology. (Note: I have not announced it yet but I am coming out soon with a much new technology 911 evaporator )

[KelogGes]

Originally Posted by Skip1

So I've looked at both systems now. The only thing I can seem to find is the rear deck lid evaporator for RennAire - does it use the stock one or a Griffith's version?

Skip perhaps you might want to know about A NEW KID ON THE BLOCK and what I am doing for a new and different perspective for the latest technology micro-channel 911 A/C PFC'S (smile)

My full blog here
I make Parallel Flow Micro-Channel Condensers for 911's front and rear

Current Development custom RSA project
I make Parallel Flow Micro-Channel Condensers for 911's front and rear


911 Front (under body) new technology micro-channel PFC



911 Rear Deck Lid COUNTOUR FULLY SEALED new technology micro-channel PFC