The reason why there is no factory condenser coil on 911 deck lid?

Why would somebody want to put a condenser electric fan on the 911 deck lid when it basically adds air resistance (static pressure) to the engine driven fan at the air intake grill at off idle condition is beyond me.

If I were to add an additional condenser/electric fan combo, I will put it some place else other than the deck lid.

Way past me.

Come on now boys and girls. WWEST has gone on EVERY AC post I have seen in the last 4 years and stated that adding two $30 dollar fans to the decklid solves every AC problem known to man or presented in a post. Even AC problems that are known to be 1. design problems (ie. lack of adequate airflow in cabin), 2. old less efficient hardware problems (ie. barrier hoses, old tube and fin condensers), and 3. just worn out components. It also doesnt matter what your humidity %, what your ambient temps are, what the condition of your system you are using is. He has gone to war with over a 100 different posters on why NOTHING else is needed. He disputes proof in these posts that it raises engine temps or any suggestion that perhaps more is needed.. he dismisses any opinion other than his own... He even designed an AC unit for an old computer something or other if I recall... which is kind of like a Porsche... Do A Search. 100 different posts will come up. Its all quite entertaining. This is what happens when someone who lives in the coolest area of the country decides he is the expert on AC being used in places like Houston, San Antonio. Atlanta or any other HOT HUMID southern city in which EVERY porsche owner with cold AC has spent some serious $$$. So show some respect for the resident AC guru... Afterall in Seattle today it is 69 degrees in Mid August. While in Houston its 98. Surely he knows best....

The only thing I read was "Seattle is 69deg today" I think it's time to move.

Exactly!! me too!

Embellishing a BIT.....
 

All I have ever said, contended, is that if you have a factory A/C system that has marginal cooling capability then additional heat exchange efficiency for the rear lid condensor will yeild a significant improvement.

I imagine Brad's problem might be that he has already spent $$$$ by the thousands only to come to the realization ~$50 would likely have sufficed.

So, yes, this may not be a solution for the deep south, but at ~$50 and an hour or so of DIY what's to lose..?

I think you mean the OP "Steve?" My system works perfectly and cost was not a factor for me.

Only if you like RAIN, lots of RAIN.

Brad....

Just so you know...my '01 C4 already has 2 modifications to the climate control system.

1. A switch inside the center console "cubby" that I use to open the compressor clutch circuit whenever I have no need for cabin cooling.

2. A manual shutoff valve that allows me to turn off the flow of engine coolant to the heater core. That negates the loss of system efficiency by "bypassing" the reheat/remix mode of the A/C. Lighter load on the A/C compressor and lighter heat load ahead of the engine radiators.

An update, thanks to everyone who responded. Special thanks to Kuehl who sent me at no charge the correct O rings for the expansion valve. I finally got around to charging it. (had to reinstall my rebuilt weber and distributor from Porschetechnik in my 70T). I did charge it and it has too much pressure in it. Around 70 on the low side, 330 on the high side. It did produce vent temps of aroung 46 degrees when it was 80 degrees outside. Felt great, except for the high pressure. I put in about 38 ounces of Freon which from what I can gather is the correct amount for 134a and the question is, why is the pressure too high and how do I get rid of the high pressure? I did evacuate the living crap out of the system, probably 8 hours total. Any help will be appreciated. Steve

If you believe you installed the correct amount of refrigerant then there may be air in your system. Either you weren't reaching the evacuation levels you assumed or air was introduced during charging. To legally reduce the pressure you need to use a refrigerant recycling machine at an automotive A/C shop.

great! What was the temp in Seattle today? Weather.com says the high was 75! low was 59. you don't even need AC dude! Someone with a low of 60 and a high of 75 in AUGUST shouldnt be schooling the rest of us on AC. lol It was 97 here today!! glad your upgrades are working for you.

I have spent $$$$$$$ on my SC, because I enjoy it... its a hobby... i get my hands dirty. that $$$$$$$ included almost NO labor. because i did it all myself. everything from new leather, to SSI's and everything in between. My AC blows ice cold, even in the deep south... i have no issues even at 96 degree ambient temps and 90% humidity. I have a $50 fan, on my fender condenser. Have no desire to dump the heat in my engine bay so a fan is part of the equation. But its only part of the equation for most of us. There are no sour grapes here. the AC was less than 10% of what Ive spent playing on this car and i drive in the summer in houston! :)

the bottom line is that you are in an area of the US where it is 70 degrees in the middle of August. Hell a fan blowing on you would be adequate there. I don't even use my AC at 70 degree ambient temps. Its 75 when I wake up at 5 am from Mid May until Mid October.. for the rest of us you need a wholistic approach. As proven by griffiths, rennaire, retroaire, and zims. choose your guru. they all do real world testing. and YOU are the only "guru" disagreeing with ALL of them... and you act as if no one has tried a couple of SPAL fans. It doesn't work effectively at ambient temps above 90, with 50%+ humidity anywhere in the USA. Deep south or not.. Move to Houston in mid august for a month and try it! So stop with all the SPAL fan BS. for most of us its part of a bigger solution not the entire solution.

Thats like saying a SPAL fan on your oil cooler make up for a worn out, clogged and leaking oil cooler or that the coolers of 1975 are as effective as the ones made today.. Its BS. These old systems need maintenance and fresh upgraded parts on occasion to really provide a effective cooling experience whether its AC or oil. SPAL fans don't replace maintaining the system. Its BS. everything on these cars will need repaired. They are 30 years old. I'm calling you out on the BS. You are misleading new uninformed owners who don't know what good AC requires in most parts of the country.

Most of my "mods" arose out of traveling to/from Daytona for the 24 hours, or Memphis (home town) during the summer months. Horrid heat/humidity in August in Alababma, Arkansas, etc. Both my '99 C2 (gone) and my '01 C4 have spent years "stationed" in Memphis, Olive Branch, really.

The coolant flow shutoff idea actually arose as a result of losing one of the radiator/condensing fans one HOT day on I40 near LR in construction zone stop and go traffic. Engine temp began rising and it didn't take much troubleshooting to figure out why. August, Arkansas, HOT, cannot use A/C without the engine overheating......wife.....

A/C is substantually more efficienct if you can bypass the reheat/remix cycle. You can do that by selecting MAX cooling (fully closes reheat/remix blend door/vane) but then even at the lowest blower speed it might freeze your butt, all without the engine temp. rising.

Oh, early "travels" were with our '78 Targa (whale tail space accommodates fans), our '88 Carrera has never been south...

Brad, it's no use, so why bother?

I live in the same state as he does, except on the other side of the mountains. Over in this part of the state, it's more like desert - our summers get to be 90+ for weeks at a time. Luckily, we don't have the humidity problem that those in the SE do - and that makes the heat bearable. But you are correct - when I lived on his side of the state, we didn't need AC. I never used AC over there, and only wanted it a few times in the 30 years I spent there. None of our houses had AC, and we never even thought of installing it. It's a different game in Western WA.

Having been in Atlanta in the summertime, I completely understand why folks would *need* good AC. And there is no way that any add-on condenser fan is going to make the evaporator work better. After having read TONS of these AC threads, it is my opinion that the stock condensers in a Carrera are barely adequate to the job if the evaporator is upgraded. Further, if the front condenser is then upgraded, then the system *will* work properly, even with R134a, and in hot, humid places. If you further upgrade to fender mounts, you can keep meat cold in your cabin in Houston. :) "Horsepower costs money - how fast do you want to go?"

Damn, here I was planning to drive the C4 to Memphis, now I guess it has to be the '88 Carrera and leave it til next fall in order to disprove the naysayers.

"if the front condensor is upgraded,...."

So you would agree that the factory A/C's "base" shortcoming is lack of adequate refrigerant condensing (cooling) capacity....

Then what is your arguement against increasing overall, full time, efficiency of the rear lid condensor?

Dont drive to memphis., live there for 2-3 weeks. That means heat soaked cars in the grocery store parking lot, stop and go traffic. different humidity levels, etc.

Highway driving on a road trip wont prove anything. the factory system is generally ok in that scenario.

More heat in the engine bay. Doesnt address condenser volume issue. Doesnt address efficiency of old tube and fin design.

Wouldnt it be better for a scant $500 to have a fender condensor (like a ZIMS) where you not only increase the condenser volume but also have the hot air removed from the engine bay which will also lower the temp of the deck condenser since you are cooling it before it gets to the deck? plus its adding a more efficient design with a fan in between the front and rear deck so it makes a significant difference.

It kills multiple issues (volume, heat, efficiency, your fan) with 1 solution. anywhere in stop and go it reduces the engine temp issue. the spal fans only make the problem worse as you are adding more hot air.

think though this before you speak. most of us could not live without AC like you can.

Its not thosands of dollars.

The purpose would really be to leave the car in the hands of my nephew in Olive Branch as has happened serveral times previously. I trust him to provide a true to life test of the A/C.