Another boring AC thread - installing a 993 condenser in a 3.2 Carrera

[Wavey]

Nice work! That S-brace is clever; no stress points and it will isolate shock and vibration from the condenser. And you'll probably get much improved performance from the OEM deck condenser with all that crap removed! RE: the washer tank, I deleted mine and ran a bicycle water bottle & cage in the trunk, near the pump. You'll never need that much washer fluid!

[NathanR]

Today I crimped my first hoses. The hardest part was getting the fittings onto the hoses (then I figured out putting a little oil on them first. I had enough stuff on hand to make two

Was also able to extract the front condenser, it and a lump of debris as well

[NathanR]

Originally Posted by Wavey

Nice work! That S-brace is clever; no stress points and it will isolate shock and vibration from the condenser. And you'll probably get much improved performance from the OEM deck condenser with all that crap removed! RE: the washer tank, I deleted mine and ran a bicycle water bottle & cage in the trunk, near the pump. You'll never need that much washer fluid!

Hey Dave, glad to see you checking in. That's a good idea on the washer reservoir. I almost never use mine.

As you can see, I decided to keep the deck lid condenser. I spent at least an hour fabbing that brace. Lots of trial and error. It does look pretty cool. The ironic thing is, all that stuff is shoehorned in there so well, it's almost unnecessary.

[NathanR]

I also decided to go for an updated evaporator, and ordered one from our host. Also ordered a bunch of #6 hose to connect the front and 993 condensers, and uprated evap blower fan from griffiths.

Was going to start extracting the evap Box but ran out of time. I'll have to remove my stereo amp first, which means no tunes for the remainder of the project. Next weekend...

[NathanR]

Originally Posted by RSTarga

use the proper size hose for the fitting, no reducers. You will lose cooling efficiency.
Nice job.

My oem setup was #8 all the way to the front condenser with a reducer at the end. Of course, I wasn't real happy with its performance...

[NathanR]

Originally Posted by DaveMcKenz

Hi Jack,
Here's some average good numbers:
low 25-35 PSI, High 180 PSI OAT 90 degrees vent temp 38 degrees @ 1500-2000 RPM. Windows closed fans speed high.
Good luck,
Dave

Thanks for posting this Dave M. I'm going to need this same info in a few weeks. Also, here is some related info I cribbed from a Charlie Griffiths post:

I think the high side is somewhat influence by the effectiveness of your condensers, fwiw.

-----------

Hi side 134a pressures vs temp


80-85F = ambient times 2.4 X 1.05 or the + 5% rule
86-90F = (ambient times 2.4) X 1.1 or the +10% rule
91-95F = ambient times 2.4 X 1.13 or the +13% rule
96-100F = ambient times 2.4 X 1.15 or the +15% rule
101-105 = ambient times 2.4 X 1.17 or the +17% rule
106-110 = ambient times 2.4 X 1.20 or the + 20% rule

Here is how you apply the rules:
Say you have charged the system with a known quantity of R134a refrigerant (grams or ounces or whatever) and the ambient temperature is 95F. Take 95 and multiply it by 2.4 = 228 psi and then multiply that by 1.13 = 258 psi. Now consider if you really had this pressure well that would be in a perfect world. Depending upon whether you parked on black asphalt or if the expansion valve was opening or closing this mean target of 258 might swing up to 270 or so and frankly that is pretty good in a 911 with R134a at 95F. Or, if you are testing with the deck lid down and your services hoses are holding the deck lid up an inch or two that would reduce the effective air flow across the deck lid condenser and drive pressures upward. Other things that can drive up the high side might be the sun beating down on the deck lid or maybe you just completed a few 0-120 mph test runs up and down your driveway (like I do).

[kuehl]

Originally Posted by NathanR

just completed a few 0-120 mph test runs up and down your driveway (like I do).

I was doing 148 runs... until a black bear appeared in the driveway

[wwest]

You might wish to reconsider the placement of the 993 condenser rather placing it in direct sight of the engine/exhaust/CATALYTIC converter.

You can easily verify for yourself how much adverse effect your current placement has.

Paint a partially full, <25%, can of R-134a flat black and connect it to your guage set.

Let the can acclimate to the atmospheric temperature and note the pressure.

With the engine/exhaust/catalyst "warmed" to normal operating temperature place the can inside the fender well in what would be the approximate center of the new condenser.

After ~5 minutes note the pressure....

PS: I can't tell for sure from the pictures but you seem to have the condenser installed 90 degrees from optimal insofar as preventing the refrigerant oil from pooling at the bottom of the tubes.

[kuehl]

Nathan,

Don't fret about the minor heat your fender condenser might see from the cat.
Many people have designed their own fender condensers and the AC improvement gain you will see is excellent.

You have a 10"? fan in your design, a 12" would be better.
Put the fan on the outside of the condenser, not on the cat side.

Griff

[gshiwota]

Originally Posted by NathanR

Do people typically remove the washer tank to route hoses to the front condenser?

When I replaced my hoses I simply had to loosen the tank. It moved enough where I could slip the hoses by. I recommend powerwashing the inner fenders before doing this as that washer tank holds a few lbs of dried mud up there.

[kuehl]

You do not have to loosen or remove the washer fluid tank.

When installing a new hoses to and from the front condenser you simply
duct tape the two hoses together, insert above the bottle on the inner fender wall side, slide them forward, go underneath with a pair of safety glasses, a light and coat hanger and pull them down and through. Just be aware of the wires for the front indicator lights.

[wwest]

"Flat" blade fans can be readily reversed and with equal effectiveness.

"Swept" blade fans lose effectiveness in "reverse".

The fan you picture should "PUSH" when turning CCW looking at/from the motor side.

[DaveMcKenz]

Originally Posted by wwest

"Flat" blade fans can be readily reversed and with equal effectiveness.

"Swept" blade fans lose effectiveness in "reverse".

The fan you picture should "PUSH" when turning CCW looking at/from the motor side.

The swept or curved blades are indeed directional, but you can sometimes reverse the polarity and flip the fan blade over. Some fans do not allow this.
Good luck,
Dave

[wwest]

Originally Posted by DaveMcKenz

The swept or curved blades are indeed directional, but you can sometimes reverse the polarity and flip the fan blade over. Some fans do not allow this.
Good luck,
Dave

As of yet I have not found a thin enough ("pancake" motor) one that can be "flipped" over. Another aspect is that sometimes the motor brushes are "displaced" in relation to the PM "stator" and therefore favor the "native" direction.

[DaveMcKenz]

I have used several fans from this company FDynamics, and they are very high quality and reversible by flipping the fan blade.

FF Dynamics 12" Ultra Electric Cooling Fan FFD12 | FF Dynamics

Dave

[wwest]

Originally Posted by DaveMcKenz

I have used several fans from this company FDynamics, and they are very high quality and reversible by flipping the fan blade.

FF Dynamics 12" Ultra Electric Cooling Fan FFD12 | FF Dynamics

Dave

Looks exactly like one I have tried and the fan hub is molded around the motor....so I don't how it can be reversed.

Emailed a question to the vendor.

[DaveMcKenz]

The fan is held onto the shaft with a nut. You unscrew the nut and pull off the blade. Then flip it and reinstall it.
Dave

[wwest]

Yes, I know... have you actually tried it...?

[DaveMcKenz]

On my 928 I had to reverse one of the fans to make it a pusher. The big one. Worked great.



Dave

[wwest]

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