Obligatory 32F AC vent image

[Jim Sims]

Finished up an A/C project today; installed a complete A/C system into a black on black '74 Targa (never had air). Put many aftermarket items from several vendors into the system (Griffiths, Rennaire and Performance Aire). Restored a factory under-dash duct and restored/upgraded a factory evaporator/blower and used the better factory steel compressor mounting bracket. System has 43 ft of reduced barrier hose, 14 reduced barrier hose fittings, a Sanden compressor, five heat exchange devices (three condensers, one evaporator, and one subcooler- Procooler), three fans, two relays, a fuse and a circuit breaker plus a high/low pressure safety switch and 1 kg of R-134a refrigerant with polyester oil. Total system weight is a little over 70lbs. Car has a Supertec 3.0 l and a Carrera oil cooler. In 95F ambient air temp with full sun (over 300 shortwave insolation) system produces copious amounts of 40F air at high blower setting and a steady flow of 32F air at medium blower setting. I found all of the above mentioned 911 AC aftermarket vendors helpful and selling products with good value.

[Carl Bauer]

Jim,

What was the total cost? Summer has hit here in Houston and I've been thinking about an A/C project of my own.

[sammygon1]

How did you restore the underdash vent. Did you recover it with vinyl? If so how did you do it and what did you use?

Also what were the high and low side pressures when the 32 degree temp was reached?

Thanks,
Sam

[Jim Sims]

Parts were approximately $3000 (depending upon what one counts). This was a "clean" new install using modern components with an effort to duplicate (within reason - some parts were NLA or back ordered forever) the factory look under the dash and in the smuggler's box.

[Jim Sims]

The vinyl and basic plastic/metal shell of the duct and above duct filler pieces did not require restoration. Temperature switch capilliary tube and wiring harness had been cut (typical ham fisted 911 A/C system removal) so they were replaced/repaired. The metal edging above and below the louvers was repainted and seams all retaped with real friction tape. Rubber control knobs and logo inserts were replaced with Porsche OEM parts.

[lateapex911]

Very impressive. Where was most of the weight added??? Or....how much was in the rear??

I would think AC in a 911 would be great....IF the weight was up front where it's easy to shed a few pounds (lighter batts, fibre fenders, etc,) and the weight isn't public enemy #1!

Lets see the install pics!

[dentist90]

Wow... freezing air at med setting! Hope your defrosters work, you may need them with cooling like that!

[Jim Sims]

The heaviest component group is the compressor and brackets at 24 lbs. This is a place (brackets) for CF and titanium instead of the usual "bling crap" that is marketed. About 75% of this A/C system weight is behind the driver. The evaporator/blower unit weighs around 7 lbs and the under-dash duct and trim weighs about 7 lbs. Given this car has a Supertec 3.0l, the extra weight of the A/C is almost inconsequential.

[Jim Sims]

Evaporator/blower apart


Evaporator/blower assembled


Evaporator/blower in smuggler's box


Sanden compressor and high/low safety switch


Hole for cold air duct

[randywebb]

That's a great install. I especially like the logos on the switches - just a detail but...

[beamonk]

Where did you get your switches on the vents? What size hole did you dtill for the assembly through the firewall?

Thanks

[charleskieffner]

congrats you beat my 37 degrees vent temp @ 100 degrees ambient outside temp! nice system! summer is here! 111 yesterday here...........113 today! but its a DRY HEAT!!!!!? LOL!

[Jack Olsen]

This would be a great tech article, if you're willing to write it up step-by-step.

[brcorp]

Where are the condensers located? Parallel flow or tube and fin? Pictures please. It that the Rennaire evaporator?

[Jim Sims]

32F air temp image was recorded while driving up a 4% grade (95F air temp) at 45 MPH (in traffic) so as one would expect I didn't have refrigeration gages attached. While charging in 80F air temperatures and the engine warm and idling at 2000 rpm (engine decklid down of course) low side was around 30 psi and high side was about 265 psi.

Temperature switch, knobs and logo inserts came from Pelican; original blower speed switch was okay so it was cleaned up and reused. New knobs didn't come with the small, metal spring tension band and this part was listed as NLA by Porsche so I salvaged the existing ones from the old knobs. I suspect there is an aftermarket source for these spring tension bands, I just didn't take the time to locate them.

Holes through "firewall" into smugglers box area were made by using the bottom half of the Behr factory evaporator/blower housing, the 3-1/4" (80 mm) flexible ducting and underdash unit as templates to position and mark holes. A 1-3/8" diameter capabale Irwin Unibit driven by a 1/2" Milwaukee Electric drill motor was used to make initial holes. These were either connected using a die grinder driving a thin 3" diameter abrasive cutting wheel or in the case of the flexible ducting hole, opened up using an air nibbler with the edges smoothed and profiled using a stone driven by a die grinder. It is important to mark and make the holes in the right sequence. The factory evaporator/blower housing barely fits in the smuggler's box and one needs the evaporator, expansion valve and inlet and outlet hose fittings in place on the housing to get it correctly placed. Sequence is locate and drill drain hole in bottom of smugglers box, then mark, drill and cut trapezoidal return air hole through to passenger side floor wheel followed by marking, drilling and nibbling hole for flexible ducting. Last is drilling the hole for the wiring pass through to the smuggler's box.

The decklid has a Performance Aire triple pass tube and fin condenser; the rear driver's side fender well contains Griffith's wheel well condensers (fore and aft of wheel), a Rennaire Procooler (combined receiver/drier/subcooler) is mounted up and behind behind the front driver's side wheel in the typical later OEM R/D mounting location. The evaporator is a new, modern improved retrofit unit from Rennaire (Griffith's also offers a similar new modern improved retofit evaporator). Hose was Parker reduced barrier terminated with aluminum reduced barrier fittings (mostly o-ring) made by ATCO.

I captured many digital images (150?) and have a binder full of notes. I may compose a tech article.

[brcorp]

No front condenser? Are the Griffith's condensers tube and fin or serpentine or parallel flow models.

Great Job! More pictures please!

[TRE Cup]

would love to see pics of the condenser installs and the pro cooler
possible to send to info@tremotorsports.com ?
Thanks
dave

[brcorp]

Jim,

If you are going to send picts out please include me too, BRCORP@YAHOO.COM

[Jim Sims]

A front condenser typically requires cutting a significant hole in the car. A "static condenser" under the car becomes a skid plate if the car is lowered - this particular car was already a candidate to be high centered on big speed bumps. The condenser arrangement used on this '74 was selected to avoid "hacking" the car and for the ease of obtaining a professional looking installation. The rear driver's side wheel well condensers are essentially invisible once the wheel assembly is remounted as is most of the Procooler up front. The Griffith's kit was straightforward to install. The Procooler was very simple to install. Available technical details for the fender condensers are on Griffith's website. Additional selected images of this project will be posted eventually as I have the time.

[Motorhead-45]

Jim,

I noticed the absence of a second pulley groove on the compressor. Did you purchase it that way or machine it off for clearance?