Originally Posted by Nick Triesch (Post 7501554)

wwest, all I need is the hi side R 134a connector adapter for my Nippondenso unit. My A/C works great. The adapter kit I bought from Pep Boy's high side adapter did not fit. Low side adapter works great!

Originally Posted by wwest (Post 7502679)

"..my A/C works great..."

Why...

1. Not powering the fan(s) until the high side pressure reaches a more optimal level increases the system efficiency, possibly making up for the cooling capacity lost in the conversion to R-134a. This has got to be the craziest notion
for MAC systems you have dreamed up yet, lol.

2. The single MAJOR shortcoming of the factory design is the poor refrigerant condensing capability during periods of extended low RPM engine operation. Adding the fan as shown, or even just powering the front lip condensor fan with the new switch might help to overcome the factory design shortcoming. Another wacky notion that could reduce air flow to to the engine, lol.

3. It is well known that our Porsche's suffer from refrigerant leakage over the long term. Seemingly, 2 years is typical for the US norhern reaches, 6 months in the hot and humid mid-south. What the cause for this leakage has been long though, assumed, to be our legacy "non-barrier" hoses, statements by the EPA, SAE, and DuPont, seem to put the "lie" to this. Amazing how someone with no Porsche AC experience nor AC design and test experience so easily calls professionals names.

In consideration of that information it might be wise to adjust our (don't include us) thinking to the possibility that other parameters, parameters other than simply the legacy non-barrier hoses, might be in play. Possibly parameters UNIQUE to our air-cooled engine cars with the primary refrigerant condensing capability mounted directly over a HOT, HEAT-SOAKED, engine and exhaust.
A yet to be proven hypothesis, lol.

Ford prevents extreme pressure excusions, beyond 250 PSI, of R-134a via a "vent-to-atmosphere" suction side (SUCTION SIDE..??!!) pressure relief valve, which you won't find on a Porsche in this forum. Historically even with R-12, pressure excursions above 350 PSI, or even as high as 450 PSI, were prevented the same way, "vent-to-atmosphere" BOVs. Although there is no evidence
of when the pressure could blow off or Porsche's blow off spec.

So, all those FACTS (myths) considered, what pressure level might our "unchecked" systems rise to post R-134a conversion given the location of the primary refrigerant condensing "container".

Beyond 450 PSI, possibly well beyond, could, SHOULD, be assumed. Heck, why not 800 psi!

An "after-run" cooling fan capability might well alleviate our historical refrigerant leakage problem, even if only the front lip condensor fan is used. Although such a concept has yet be proven to have any benefit

Originally Posted by wwest (Post 7502679)

"..my A/C works great..."

For the moment....

Buy a little insurance.

In case of refrigerant leakage the switch's low cutout will prevent compressor damage.

You're converting to a refrigerant that operates more optimally at high system pressures, the switch's high side cutout will prevent the compressor from over-pressurizing the system in the event of a (common) thermostatic control switch failure or malajustment.

The extra trinary function is typically used to power the, a fan, fans...

Why...

1. Not powering the fan(s) until the high side pressure reaches a more optimal level increases the system efficiency, possibly making up for the cooling capacity lost in the conversion to R-134a.

2. The single MAJOR shortcoming of the factory design is the poor refrigerant condensing capability during periods of extended low RPM engine operation. Adding the fan as shown, or even just powering the front lip condensor fan with the new switch might help to overcome the factory design shortcoming.

3. It is well known that our Porsche's suffer from refrigerant leakage over the long term. Seemingly, 2 years is typical for the US norhern reaches, 6 months in the hot and humid mid-south. What the cause for this leakage has been long though, assumed, to be our legacy "non-barrier" hoses, statements by the EPA, SAE, and DuPont, seem to put the "lie" to this.

In consideration of that information it might be wise to adjust our thinking to the possibility that other parameters, parameters other than simply the legacy non-barrier hoses, might be in play. Possibly parameters UNIQUE to our air-cooled engine cars with the primary refrigerant condensing capability mounted directly over a HOT, HEAT-SOAKED, engine and exhaust.

Ford prevents extreme pressure excusions, beyond 250 PSI, of R-134a via a "vent-to-atmosphere" suction side (SUCTION SIDE..??!!) pressure relief valve. Historically even with R-12, pressure excursions above 350 PSI, or even as high as 450 PSI, were prevented the same way, "vent-to-atmosphere" BOVs.

So, all those FACTS considered, what pressure level might our "unchecked" systems rise to post R-134a conversion given the location of the primary refrigerant condensing "container".

Beyond 450 PSI, possibly well beyond, could, SHOULD, be assumed.

An "after-run" cooling fan capability might well alleviate our historical refrigerant leakage problem, even if only the front lip condensor fan is used.

Originally Posted by brads911sc (Post 7503181)

What question for the original PO were you trying to answer.

LOL

Originally Posted by Bob Kontak (Post 7503319)

I am not ready to smoke him out of the hole yet.

Originally Posted by SilberUrS6 (Post 7503385)

And in written form, the insults can be sublime..

Originally Posted by Bob Kontak (Post 7503319)

I squared off with Sucker Fish last year. Ain't heard much from him since. Do a search. I kin' get real stupid.