'87 911 A/C Upgrade - "Progress"
 

So while my car was down for some other projects, I took the plunge and decided to get the AC going again. The original AC worked "OK", but when I put the 3.6 in the car it was set aside. I do need it for comfort - this is my summer street car after all.

So I looked a the options and purchased Rennaire parts to perform the conversion. I will be mixing in at least one Griffiths item - the extra center vent to replace the bow tie, and perhaps others (read on).

I went with the Procooler approach, desert duty front condenser and barrier hose, etc. My install has a few wrinkles:

-RSR 3.8 tail (Getty Design) with no provision to mount a condenser
-964 Case and AC Compressor mount with Varioram intake

So first, the easy stuff - replaced the front condenser, removed the old AC lines. Removed the evaporator unit and installed the new evaporator, then wrapped it up with the foil and foam insulation (that was "fun"). Installed the new expansion valve.


http://forums.pelicanparts.com/uploa...1241403164.jpg

Say what you will about this part from 1987, they didn't seem to go cheap! This is a complicated bit of plumbing.


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Of course, it was a very clogged up bit of plumbing as well, at least as far as airflow goes...


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The new unit looks a lot simpler!


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Starting to wrap the present. This was tedious.


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Made seals for the bottom of the box from hardware store stuff

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After installing the valve it got wrapped up too.

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One I got the box back in the smuggler's compartment, I resealed the intake with the fan resistors.

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Rennaire included sealing material in their kit.

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Back where it came from.

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Obligatory shots of the upgraded unit installed. This was a tight fit but not too bad to reinstall. Working from inside the car to guide the drain tube really helped.

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The barrier hoses are installed. I chose to start with getting these on properly then securing them underneath.

So now the more interesting part. I have two "projects" that need to be done to complete the AC upgrade, excluding the usual excitement of recharging.

The rear condenser from my stock system needs to me mounted inside the RSR tail. Has anyone done this? I'll need to fasten some, well, fasteners inside the tail to hang the condenser on - any good suggestions on adhesives for this other than Marine Tex?

The compressor is a significant issue. I have a 993 compressor, and the factory hoses that attach to that unit. I was thinking of buying a crimper (unless I can lease one from a Pelicanite) and attaching the new hoses I have to these fittings (cut them carefully from the factory hose). This is a good solution to give me factory evac/recharging ports (one is on the hose, one on the compressor itself. The only challenges seem to be the crimping and the routing of the line from the compressor to the decklid condenser.

subscribed.

btw, what is the black goo around the valve? i have that, too, and feel very tempted to try & peel it off.

also, do you think insulating the evaporator box helps? mine is open, either because a PO messed with it or it is generally that way in RHD cars. unfortunately I have not been able to find anyone to help me out on that.

Do not peel off the goo - it is needed!

I cannot imagine insulating the box will hurt things, and compared the rest of this it is the cheapest thing you can do, other than removing the bow tie vent.

A bump for the Monday crowd - here are my questions:

1. The rear condenser from my stock system needs to me mounted inside the RSR tail. Has anyone done this? I'll need to fasten some, well, fasteners inside the tail to hang the condenser on - any good suggestions on adhesives for this other than Marine Tex?

2. I have a 993 compressor, and the factory hoses that attach to that unit. I was thinking of buying a crimper (unless I can lease one from a Pelicanite) and attaching the new hoses I have to these fittings (cut them carefully from the factory hose). This is a good solution to give me factory evac/recharging ports (one is on the hose, one on the compressor itself. The only challenges seem to be the crimping and the routing of the line from the compressor to the decklid condenser.

That black stuff is called Prestite, a sticky tar tape. I think you will find the crimp tools kinda pricey. When I added a condenser and new compressor I ran all the hoses, had the connectors and then took the car to a small AC shop to get the hoses cut and crimped. Less than $100. Then I came home and used my vacuum pump and stuff to vacuum and charge with R-134A. I don't know much about the crimping but do know there are some nuances, like bead or barb fittings. Ken

Thanks Ken - the crimping tools seem to be $100-150 plus the actual crimp ferrules themselves. Did you go to an AC shop that was not car specific?

Another idea. Today I got a 993 condenser. Very light, very small. Would it make any sense to mount this on my RSR tail instead of the stock '87 condenser?

Yes, I just called around to find a small shop where I thought they guy would work with me. I think he enjoyed working on a Porsche. I have a 993 and am amazed at how well it cools with that small cond. On the 88 I have the normal front and rear condensers and added one under the left rear wheel well from ZIMS. I have a Procooler too. I'm no AC guy but I think the decklid is not the best place to put a cond. and that is why the original one is the size it is. Have you looked at putting the 993 cond + fan under the front or rear wheel well? Don't know but then you might could skip the decklid one.

Here is the 993 condenser and what I think is the matching fan. I am not married to putting it on the rear decklid, but I do not have the room up front. The inner fender on the drivers side is a possible location.


http://forums.pelicanparts.com/uploa...1241494632.jpg


http://forums.pelicanparts.com/uploa...1241494645.jpg

Most have likely seen this, but here is what the lines coming out of the 993 compressor look like. You have an output that is on a level horizontal plane before you attach the hoses.




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Worked on getting the 993 compressor hoses converted to use the reduced diameter barrier hose. Turns out they are an interesting size fitting...


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CB - the stock Carrera condenser mounts with bracakets to the deck lid hinges, then there's that center clip at the back. Those parts won't work for you?

I just finished an almost identical rebuild - Rennaire front condenser, evaporator & insulation, Procooler, barrier hoses, R12 charge. Stock compressor and rear condenser. I'm getting as low as 38 degrees at the vent. I think you'll be happy.;)

I have an aftermarket RSR 3.8 tail on my car. So I'll need to mount whatever I use up there from scratch (I asked for adhesive suggestions but no responses yet). I spoke with Jeff at Rennair today and he told me the 993 condenser would certainly work, but with the desert duty front condenser it would not really be needed. So my plan for now is to use the stock version, as long it passes the leak test.

OK, so I guess you can't mount to the hinges. There are some great structural adhesives but not so much on the consumer level. We use a structural epoxy from Lord Adhesives in the shop but it takes a special gun, mixing tubes, etc. Actually I think JB Weld could work really well for this, it just cures slow and can flow away from where you want it, until it sets up. I just used JB over the winter to repair an area on my 3.0 Carrera tail where the FG had separated from the metal base - worked great. Also used it to repair a broken rear view mirror post, which everyone said wouldn't hold but it's still together over a year later.

CB, I have toyed with the idea of using the 993 condenser and fan in the left rear fender and a desert duty up front. Let me know if you decide to part with yours.

Here are a few shots of the compressor installed for Jeff at Rennaire. We are going to convert the factory lines here to a standard size that can be crimped onto the reduced diameter barrier hose.


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In the previous post you can see what I am up against with the rear condenser. I have already removed the posts that interfered with the mounting from the tail.

I had a similar problem mounting the rear condenser in a fiberglass ducktail. In my stock tail the condenser was held by a clip to the passenger side decklid hinge and a clip to the center rail of the decklid. The duck tail doesn't have a center rail so I couldn't use the stock center clip. I hate to admit this, but I ended up attaching the drivers side of the condenser to the hinge on that side with plastic wire ties. I intend to make an aluminum bracket for that side but haven't gotten around to it... the suspension rebuild I'm in the middle of is taking priorty. The wire ties have been on for a year now and are working fine.

I spent some time preparing the rear decklid to receive the condenser. I went with JB Weld holding on AL brackets. I used a fairly large base for the brackets and drilled holes in them to give the two part epoxy a good chance to grip the metal. The factory condenser has brackets that were easy to match up to on the rear. On the front I added some angle which will have a foam strip ala the factory retention method.

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I put a single big ass condenser up in my turbo tail. Mounted it to the deck lid so the tail slips over the top.
Couple of puller fans activated off the trinary switch and done.

Condenser was 28.5" x 15". So really big! No secondary condensers at all.

http://forums.pelicanparts.com/uploa...1243950835.jpg

http://forums.pelicanparts.com/uploa...1243950875.jpg

There's a whole thread on how to do this. Get 30Fs' at the vents. Doesn't sell much product though like underbelly, front mount or wheel well condensers.......

Here are some images of the rear condenser for Jeff at Rennaire:

http://forums.pelicanparts.com/uploa...1244231221.jpg


http://forums.pelicanparts.com/uploa...1244231236.jpg


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More progress to report. Cleaned out my old factory rear condenser using an air driven cleaning bottle and acetone (this is the only original part of the plumbing left). Rennaire finished modifying the 993 compressor connections by welding new crimp on hose ends to the factory hose adapters. I used my new crimping tool to connect the lines and got the two way Ho-Lo switch plumbed in. The two way sensor allows for conventional hi-lo compressor cutoff and the operation of an auxiliary condenser fan relay for the rear if you are so inclined - I am saving this for a future upgrade path if needed. I also plumbed in the procooler. When I went to pull a vacuum on the system I found that my ebay gauge kit did not include the correct fittings for r-134a type hose ends. Bummer. So while I wait for the adapters to arrive, the system is only a leak test and charge away from a functional test. Finally!

http://forums.pelicanparts.com/uploa...1247543938.jpg
2 way Hi-Lo

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Welded adapter

http://forums.pelicanparts.com/uploa...1247543981.jpg
Insert hose and crimp!

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Rennaire did a nice job with this

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EBay AC tools

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The hoses tuck into the tail and engine compartment fairly well, although they are not pretty

http://forums.pelicanparts.com/uploa...1247544141.jpg
Took this setup for a spirited drive and so far no tire interference issues

All Charged Up!
 

After a false start using a poorly made r-134a charging adapter I got my system charged a few minutes ago. I will let the pictures tell the story:

http://forums.pelicanparts.com/uploa...1249667597.jpg
Charging Setup established. Off camera is a very large shop fan blowing on the rear condenser. I did not raise the rpm above idle during the charging and measurement process.


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Ambient Temp.

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Quantity of r-134a added (lbs and oz). This was on the low side of what Rennaire recommended and I left this as a starting point and will real world test it later today.

http://forums.pelicanparts.com/uploa...1249667739.jpg
Hi and Low side operating pressures. Also seem on the low side.

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High Side to front condenser

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High side to compressor

http://forums.pelicanparts.com/uploa...1249667857.jpg
Compressor case temp

http://forums.pelicanparts.com/uploa...1249667884.jpg
And the money shot - Center vent temp with stock fan on "II" :D

Nice.
Only trouble is you'll need driving mittens.

LOL - As a Vermonter you are familiar with this. Good problem to have, I hope ;)

another procooler position
 

This is how I positioned the procooler in my 930.

I have 235/40x18 front tires and I need as much tire clearance as possible.
The procooler installation up the page a ways wouldn't work on my car because the tire would grind up the hose during left turns in no time.

You can see where my left front tire rubs the inner fender well at full left lock sometimes.
http://forums.pelicanparts.com/uploa...1249676243.jpg

I have been driving for a while with the p-cooler in this location and no problems - BUT I am only using 7.5x17 wheels with 205's up front. Track tires could expose something bad and when that time comes I will look carefully :)

EDIT: What may not be clear from the pic is that I put the canister as high as possible in the wheel well. So high that I could not clamp it to the facotry attachment and the line from the evaporator is in a potentially bad position. But so far all is well.

Real World Test
 

I have taken a long drive with the AC on and it works like a charm! Yet to remove the bow-tie and replace with something that lets me direct this air, but using the stock (large) vents on the '87 provided real comfort with my all black interior. So color me "cool blue" and satisfied for now! Still a ToDo for the wiring of the Hi-Low switch and perhaps a revisit of the measurements with Rennaire as a sanity check.

One result of this effort is that I am now somewhat stocked up in the garage to work on basic AC systems. This is the tool list I accumulated:

• Serious Vacuum Pump (ebay)
• Ho-Low Gauge Set and manifold (ebay)
• Additional Hose for refrigerant tank to gauges with valve (ebay)
• Set of r-134a to r-12 hose adapters (ebay)
• Solvent "blaster" cleaner (ebay)
• Vent thermometer (ebay)
• Digital Refrigerant Scale (ebay) - this will be useful in many garage projects as it handles over 200 lbs
• r134a tank to r-12 adapter (ebay)
• Manual hose crimping tool with three dies (ebay)
• 30 lb tank of r-134a (Coolgas.com) this had to ship from unregulated TX to PA since I do not have the correct paperwork to buy from a PA dealer :p

So did it cost more than just taking the system to be charged at a professional? You bet. But I love tools and always seem to find a use for them later after the "last" project is done. If local Pelicans need to borrow these the offer is out there.

Well done. Congrats on your results and your new tool stash:D

Thanks. I'll repeat my offer for local Pelicans - these tools are available if you find yourself needing them.

Chris,

One year on, how do you like the system? Any changes you would make.

My only suggestion that would change is I have an 85 model and my vents are not as big as yours, so while in there would try the PerformanceAire mod and drill another opening for cool air out into the car. As small as the earlier vents are on the dash feel that it would be needed.

Glad you are open to loaning your tools. I have basics (gauges and vacuum pump) and loan them out to local friend who I know are trained on using them.

Joe A

More air (if it is cool!) is always good. I probably will remove the bowtie and maybe even drill another hole down there. But other than that, no changes needed!