I did it too...Pro Cooler Mod for my A/C
 

So, I'm a newbie to this forum but have been reading it since I purchased my 1974 Turbo Style 911 a couple of months back.

Mine is a beautiful white, wide body, 911 coupe with a new 2.7 litre engine, transmission, power windows, power locks, alarm, new interior and exterior. This car was a steel. However, I was not so pleased with the A/C when I brought it back from San Jose, CA. I had asked the guy I bought it from if the A/C worked and he said yes, I turned it on and it blew cool...but not cold. In San Jose, this was not a huge issue I guess. So when I was driving it through the desert to my home in Albuquerque, NM (also the desert) I found out how cool it really blew...and let me say, it really blew...not so good.

When I got it home the first thing I had done to get it raised about an inch. It was so low that the front tire rubbed against the A/C receiver/dryer when I made a right hand turn. The next thing I did was read all the forums here and other sites in reference to the A/C systems for the Porche 911's and found alot of information. Much of it said that the only way the A/C systems would work is if you have (2) condensers or more and change out all the existing components for hybrid components. My pocket book was feeling the pain...so I opted for a compromise with the option to upgrade the system one component at a time until I was happy with the outcome.

The car was equipped with an after market A/C. It had an original York compressor, an aftermarket evaporator coil...VW COOOL, a standard receiver/dryer in the right wheel well and one condenser mounted on the rear deck above the engine. So now being exposed to mechanical systems...working in the engineering field I started asking some questions about the existing components on my car. The first is "was the evaporator large enough?" Mine was about 2" deep and about 8"x12". Everyone said yes, and it worked. It's motor blows three speeds. So I Pulled it out, cleaned it made sure the carpet didn't cover the coil and put it back. Next I installed (2) two electric fans in the tail on top of the condenser coil blowing into the engine compartment and blowing across the condenser coil and hooked in a relay so that they turned on when the clutch engaged on the compressor. (worked great)...still the air was hot and my York compressor was not holding the cahrge for more than a few weeks. I did not add another condenser coil as the hoses were already long enough and I didn't want to install more stuff on the car. Next I removed the York compressor and installed a new Sanden 507 and a Pro-Cooler by Rennaire. Only three items were purchased...A pair of electrical fans, the Sanden compressor and the Pro-Cooler. Everything else stayed the same in it's original configuration.

My installation did not go per plan because of my aftermarket A/C, but I managed. I took it to my mechanic for a vacuum test and some minor A/C hose modifications and then charging.....and the outcome.....it blows sooooo coooold. Outside temps at 97 to 100 degrees F and the inside temp somewhere between 115 and 125 degrees, turn it on and within 5 minutes I have to switch it to low. It's awesome. The car always runs just a hair under 250 degrees in this heat...and the electric fans I installed really helped the engine heat as well, dropping it to just about 210 degrees....

That's my story....any questions??

Pics and let's hear about the fans. good job!

What would you say made the most difference....the fans or the pro cooler?

Curious about who worked on your 911 A/C in Albuquerque...and your opinion of their skill.

I will post some pics of the equipment and where it's all mounted. I'm not one with a camera while I go. As far as what made the biggest difference, I was talking with my mechanic as he had installed a couple of Pro-coolers without the fans and new compressor. He said that the Pro-cooler did help the system but it was no where near where mine was. I would have to say that it took all three upgrades to get the cold air.

Is it bad to bump your own post?...I think not.

I have been using Hans Wittler Automotive. They are probably one of the best. I have been told that from other mechanics and other shops as well. I know that they also fix cars (on occasion) for the Porsche dealer as well. My only gripe about them is that they are so busy on any given day that I usually have to wait in line and sometimes it takes a little longer than it should. But their workmanship is fantastic.

This is my car. I will take a pro-cooler installation and a picture of the other components tonight if possible.

http://forums.pelicanparts.com/uploa...1123598139.jpg

I am doing a similar upgrade right now:
new barrier hose, procooler and evaporator from Rennaire.

I am very interested in your fan installation. I have been trying to choose the right Spal fans to instal - looks like the only ones that will fit in the turbo tail is the 7.5 inch push fans.

Please send pics of your fan installation.

BTW mine is a '86 m491 cab.

Johan

BTW that car looks awesome!

I used (2) PermaCool Turboflex #19010 fans. They come with a steel housing. They are 10" fans and put out about 2500CFM each pushing air into the engine compartment through the condenser coil. I had to remove the fans from the housing. I bolted one of the mounting brackets that attached the steel housing to the fan to the rear deck bolt holes where the original grill used to mount and then the other end of the fan's mounting bracket using the plastic tie's provided with the fan through the coil. Basically the two 10" fans sit right on top of the condenser coil. I also had to grind down the bolts that hold the wire mesh up against the grill opening on the tail so that the fans would clear. I also used spacers so that the fans would clear the rear hood. In essense the fans are kinda angled in the tail. Most of the fan is over the condenser, but the other end is about 2" over the rear hood. It's the only way I could get them to sit in there, but they are extremely efficient. I will take a picture of the fans through the grill tonight.
http://forums.pelicanparts.com/uploa...1123605086.jpg

I think the 10" was a good choice. I am not sure if the 6 to 7 inch fans will have the guts to push that much air. Maybe I need 4 6 inch fans to do the job.

I look forward to your pictures. Thanks for the description.

JB

Here's the pics of the installation...after the fact.

This is the electric fan I installed in the tail cavity. There are two but they don't show in the camera really well.

http://forums.pelicanparts.com/uploa...1123633393.jpg

This is from below. Note the plastic pull type achors through the condenser coil. They come with the fans. Remember that I removed the steel shroud from the fans so that they can mount in the cavity.

http://forums.pelicanparts.com/uploa...1123633541.jpg

This is the new compressor...a Sanden 507 with some custom hose connectors.

http://forums.pelicanparts.com/uploa...1123633604.jpg

The Pro-Cooler in the front wheel well.

http://forums.pelicanparts.com/uploa...1123633665.jpg

And this is the evaporator behind the passenger floor boards. One with carpet and one with the carpet stripped away.

http://forums.pelicanparts.com/uploa...1123633737.jpg http://forums.pelicanparts.com/uploa...1123633763.jpg

Elu,

That last pic is fascinatiing. I don't profess to know alot about pcars, but it looks like your evaporator is mounted vertically, as opposed to horizontially on my 84. With a HUGE open area for pulling in warm cabin air. How is your evaporator fan mounted? Do you have a traditional smugglers box lid and fan or something else? Do you have any pics of the smugglers box opening and the plumbing into the behind the dash plunum area?

Yes you are correct, it is mounted vertically. It is an after market VW COOOL unit that slips down in the smugglers box. It doesn't fit perfectly, I actually had to bend the smuggler box flanged opening up a little in the corner to get it to drop in. The VW COOOL unit is completely enclosed so what you see is the open side, the rest of the box is completely enclosed in a plastic casing along with the squirrel cage fan....and the fan blows hard. The opening into the A/C duct fits right into the evaporator box...it's all a perfect fit.

When I bought the car, the opening you see was chopped in. It was a really bad chop job at that. I grinded it down and flanged the opening with a monkey wrench so that it matched the evaporator coil size and shape and then put that door protector plastic over the rough metal flange I made to seal the opening against the coil. I only did it because I hated the way it looked and I wanted to seal the air flow. It's still not pretty, but it looks 100% better than it did before.

Elu,

Very well thought out and obviously a success!

Where did you get the fans?

Simon

Elu,

this is a very impressive installation. Thank you for taking the time to get pictures and share with the rest of us. I do not think that I will be able to get the fans into the back of my car. There is very little space between the condenser and the lid.

Thanks again.

Elu,

Did you set the fans to 'push' mode? Does it draw air from the outside and pushes it down onto the condenser/engine compartment?

I thought these fans were 'pull' fans?

Simon

There is a way to install them below the condenser coil although you would have to modify your air filter casing. There are a few places here in the forums that talks about it.

I got the fans at Summit Racing. Ordered over the internet. The fans were reversible, however they are better pull fans because of the blade shape. Pushing the air with the fans really didn't do the trick. I removed the fans from the steel housings and flipped them upside down, they are still wired as pullers however since they are flipped upside down on top of the condenser they are in essense pulling the air from the outside down into the coil and engine compartment. It works much better that way and it was an easier installation as far as bolting them to the car.

delicate bump

my upgrade
 

I also upgraded my air but I changed the rear condensor to a paralell flow unit and installed a 12" Puller fan, I had to backdate my heat though. Here is a pichttp://forums.pelicanparts.com/uploa...1124392986.jpg

That's a really interesting install for the electric fan. How does your system work?

Alex, can you provide some details on the condensor, i.e. supplier/manufacturer and price? It looks curved as if designed for a 911 rear deck. Did you do anything else with your system and what were the results...are you happy with it?
TIA

Hello, I guess by my original post it would imply that "I" myself changed the condensor out. I had Vertex Auto do the AC upgrade, they changed everything, compressor (Sanden) rear condensor, added puller fan, hoses, RD, exp valve, evaporator (aftermarket) blower motor (again aftermarket). My A/C blows freaking cold! But it was not cheap, $2k installed...

Alex,
What evaporator did they put in?

elu,
great writeup..hanks for taking the time.

it would have been an interesting data point just to see what difference it would have made if you had just bought a cheapo receiver/drier from like napa for about $30. they supposedly work just fine..i think the jury is still out on the exact gain with the procooler. great idea on fabbing the rear deck to accomodate two 10-inch fans. this means i can go this route instead of cutting up my air box this fall. i'm going to add barrier-style hoses this fall as well. what about you?
ryan

Ryan,

To be hones, I didn't want to just try the standard receiver/dryer...and I could have...but from everything I have read everywhere (huge amounts of information) everyone said the same thing, their air conditioners just didn't work. Mine worked when I got it but had a small leak in the York compressor. It lasted a few weeks at best and didn't blow cold at all....just cool at best..Probably fine in CA, but living in New Mexico with 100 degree temps, I couldn't take it and I didn't really want to spend the money on the compressor only and experiment to see if that would fix it...so I opted on the procooler mod. I have read a few positive reports on it and I believe that everyone who has done it says that is does give you an extra 20 degrees and I wanted every extra bit I could get. Even my mechanic said that mine was the coldest he has ever seen. He didn't think that doing what I wanted to do to it would fix it and he tried to talk me into (3) condensers. For $5000 total price...I don't think so. He wouldn't do the work because he said it most likely wouldn't work and he didn't want to be responsible. So I did it myself and had him vacuum check the system and recharge it. He had installed a pro-cooler on another one earlier this year, but it was nominal at best and he could not figure out why mine was so much colder. I honestly think it is the combination of everything I did to it, procooler included.

The electric fans are definately helping as well. I was worried about noise, but you can't really hear them over the engine. I don't know what kind of hoses are in my car. I know that the system was upgraded a couple of years ago from the R12 to a 134 system. So I imagine that the hoses are newer. They seem to be in pretty good condition. How can you tell if they are barrier type or not?

Evaporator
 

Ryan: They used a evaporator from a BMW M3

R134, new hoses, front and rear condensors, and a 18 inch square static underneath that I had lying around, seiko compressor, $30 NAPA R/D, I'm getting 36 to 38 degree air on a 90 degree LA slow freeway traffic ride home. Oh, I made a subcooler like Jim Sims, instead of the Procooler, cost was $25, plus two extra short hoses between the subcooler and both sides of the evaporator which I had made when I when I was having hoses made for the rest of the car.

Can someone post a link to Jim Sims subcooler thread? I can't seem to find it.
TIA

So how many people have done Jim's modification? It looks easy and cost effective.

Not hard. A little futzing around to get the subcooler stuck behind the steering rack and getting the hoses to fit properly. With short hoses between the subcooler and the evaporator, you don't have a lot of room to play. I would buy the hoses and fitting loose, get them fit where you want, mark them with a sharpie and then have them crimped.

Hi Elu,
Do you still have the fans on top of the condensor? The reason why I asked this question because I found someone claimed that pulling mode fan on the bottom of the condensor is doing better job. Not sure if this is true. What is your opinion?
Also, do you still remember the sources where you get the fan from?
Last question I have is wiring the fan, if you still remember.
Thanks Elu.

hey rnln,

Most definately they are still on top. And they are still performing in top condition. I can't complain. No mods to the airbox or filter that way. Here is a link to the purchase page. http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRM%2D19010&N=700 +115&autoview=sku

As far as wiring, they are wired into the clutch of the compressor via a relay. I am bringing power from the battery in front. I routed a nice thick 8 guage wire through the front wheel well and under the rocker panel. And I made sure to tuck it behind hoses and such to keep it safe and then routed it through a small hole in the rear wheel well and over to the relay at the compressor. I used a 20amp in-line fuse in the front trunk. It was very easy, just time consuming. If you read more of this thread you will see that the fans are pullers and I flipped them upside down and mounted them on top of the condenser coil so the are now basically pushers. Pullers would be more efficient...however because of the size of the fans and the associated CFM's they work wonderfully and they fit in the Turbo tail cavity.

I hope that answered your question.

Thanks Elu,
Can you point out the disadvantage of getting power for the fan from the AC compressor instead of from batery? Or maybe from the rear fuse box (on the left side of the engine bay)

Because the fans draw 6.5 amps each that would be about 13 amps total load. There is a start up current of about 175% of the running load current so that would bring it up close to 23 amps during start up. A 20A fuse would cover it. I don't believe there is power at the compressor, just the control circuit. If you have a spare 20A fuse at the rear fuse box then you are in business. But you definately need a dedicated 20A fuse.

Thanks Elu

I want to thank you guys for this information I am adding the pro cooler to my 1980 911SC next week, it has the original R12 and factory air. My blower motor froze up last week and I figure since I have to break the seal on the evaporator might as well it make it colder.it blow about 50 deg now. I am going to do just the Pro Cooler first because I am curious to see how much difference it make by it's self. If i don't get the results i am looking for then I'll add the fans and so on until I get something I can live with. It is not uncommon to get temps. of 103 here so you really need air conditioning.