Opinions on Electric Air Conditioning Systems

[RTincher]

I’ve now owned early 911’s for 40 years, primarily in Houston and Atlanta, but I have intentionally never bought one with A/C due to all the extra weight, the required chassis holes and plumbing, the impact on engine and interior aesthetics and the inefficiency of the systems.

I am now in the process of a having a full restoration/build done of a “gentleman’s hot rod” - a ‘73T with RS flares, enhanced suspension and a 3.2 EFI twin plug engine (with vintage aesthetics). Due to advancing age and the attendant preference for creature comfort, I am considering having one of the electric A/C systems installed, and am looking into the system built by Classic Retrofit linked below. I am largely a purist in terms of aesthetics, so am hesitant but it appears that this system can be installed in an unobtrusive way.

https://www.classicretrofit.com/prod...c-911-full-kit

I’d welcome hearing about peoples’ experience and seeing installed pictures with this or similar systems on the following aspects:

- cooling effectiveness
- installation aesthetics (how was air piped into interior with no ‘69-73 factory dash vents, smuggler’s box install?, fenderwell install of condenser?, required chassis holes/cuts/etc.)
- dash mounted on/off switch, i.e. has anyone tried using a vintage Porsche dash switch instead of the modern switch included with the Classic Retrofit system?

Thanks for sharing your experience, this seems to me to be one of those potential “modern” upgrades that could be worth using on an otherwise vintage look restoration.

[mac73s]

If you are not already aware, there are TONS of postings and therefore pages on this unit in PELICAN under the 911 TECHNICAL forum. It was started by the fellow in the U.K who makes these units. I admit to having lost interest to keep reading them, but it seemed to be in development for quite a while but I think (hopefully) it is now a fully sorted system. The PELICANITES can tell you for sure based on their real world experience as a number of them have installed it in various hot and humid climates in the U.S. A fellow PCAR guy near me installed one in his 911 SC and has high praises for it. It is not inexpensive. I too have given it consideration for my 72 hot rod, but it is primarily a 'cars and coffee' car and I have other PCARs that have 'air' if needed.

[Arne]

I did some research on this on Pelican, and if my car had not been a factory A/C car I probably would have gone this direction. Instead I upgraded the factory system, at a cost of $3000. I'm going to guess that the electric system's cost would have been similar.

I seems to me that the body shell modifications (holes and such) would be less invasive on this electric system.

[RTincher]

Thanks to both of you, and that Pelican thread is helpful. On first read I’m initially leaning toward waiting for further development, but will read through another 1-2x to better understand.

Bob

[mac73s]

Thanks to both of you, and that Pelican thread is helpful. On first read I’m initially leaning toward waiting for further development, but will read through another 1-2x to better understand.

Bob

Remember too, that they recommend one of their upgraded alternators because of the demand of the system...I have an 86 3.2 engine with its stock alternator and that say even that is insufficient.

[targatuesday]

There are pros and cons to every modification one can make to their 911. Here are a few based on everything I have read about this system.

Pros:
- No loss in HP when running A/C because the compressor is not connected to the engine (Classic Retrofit says their upgraded alternator requires approx 1HP more than stock to spin).
- No visible changes in engine bay. All components can be mounted in the front storage compartment and inside the fenders.
- No visible changes to the interior. Only a single on/off button is needed and thus can be hidden or removed completely if using an existing switch or slider.
- As good or better cooling than original A/C depending on which reviews you read.
- Vendor has the ability to provide software updates and additional functionality over time as the tech improves.

Cons:
- Depending on year of car it may be a challenge to find locations inside fenders for single/multiple condensers. If you have an external oil cooler, original battery boxes, etc. some priorities and decisions may need to be made as to where to locate various pieces. The vendor does offer some solutions for replacing the washer reservoir with a newer item, etc.

Neutral:
- Most cars will need to upgrade to the Classic Retrofit alternator or similar.
- In hot weather states 2 condensers will be needed.
- Owners may wish to add Dynamat style insulation and clear heat-rejecting window tint to keep the heat out and the cool in (these mods would benefit any A/C system).
- Some well known Porsche restoration shops and resto-mod builders are using this system in many of their builds.