A/C Upgrade Project starts tomorrow!

[mthomas58]

Originally Posted by tsuter

I wonder if you could take a reading of the temperature off the body of your compressor after a 20-30 minute run on A/C w high cooling. Thanks.

Also interesting would be a temp reading off the top/front of each condensor vs the vent temp at the same time as above.

Are your condensers in parallel with #6-6-6-6 side and #8-8-8-8 side lines or in series all #6 lines? If series, what is the order from compressor to proCooler?

Unfortunately, I don't own an IR Thermometer but let me check with some neighbors.

What I can tell you is that the suction line at the compressor was not cold to the touch at the conclusion of charging but I have not checked it after running the car on the road at higher RPMs with good airflow (but I will). The ProCooler was ice cold and sweating.

Any idea what the "normal" operating temp range is for the compressor?

I believe all of my high side hoses are #6 and all suction lines are #8. High side lines run from the compressor to rear deck condenser to rear wheel condenser to front of rear wheel condenser to front bumper consenser to ProCooler to Evaporator. Suction lines run from Evap to Procoooler to Compressor.

Tsuter, looks like you're already in the 90's in San Antonio. How's your system cooling?

[tsuter]

Originally Posted by mthomas58

Tsuter, looks like you're already in the 90's in San Antonio. How's your system cooling?

96F Sunday 103F at the condenser gave 32F at the vents on high fan speed and temp dial at about 80-85%. I'm expecting a 70-75F differential when its 110-115F. Over 40F vents at any ambient would be disappointing. We'll see.

But I am interested in compressor temps. Not sure what they should run at. I may be a bit low on charge.

[mthomas58]

Check out this site:

http://www.climatictesting.com/Automotive%20AC%20System%20Test%20Stands.htm

Says that compressors may run at 250 degrees

[Mike Andrew]

I am still not there. A few distractions have taken precedence the last several days. I hope to wrap everything this weekend but that is iffy as it will only be 60ish here and that's a bit cool to charge.

[mthomas58]

Originally Posted by CatSkynr

It will be concealed. No need in disconnecting anything. I made loose fits before pinning the lines to the pan. You will need to move inboard to the next indention level on the pass-side pan after making the cross run which is roughly 6” inboard to have enough slack in the back. By the time you make it towards the rear, follow the indentation to fall into the original trench (just past the rear door jam when it makes the turn inwards). Pre-drill your pilot holes into the pan by holding the clamp in place over the hose then caulk the original holes closed. When you do this, you end up with exactly 2 unused C-clamps (where the line ran under the splash guard), you reuse these on the front-cross run. Fits perfect, you’ll see when you unbutton your line. Then you will need a few ADEL clamps to pin the line in place next to the hi-side run. Just tack them on the other side of the c-clamps, makes for perfect spacing. I zip-tied my lines all in place at the drier side first, then clamped them to make them look uniform. As you can see in my pic, I spaced them the width of the tie, which worked perfect. One tie loose around ALL the lines, then zip a tie around that looped tie in-between the hoses. Snug them all up.

I plan on making a skid plate for the front and using the original stone guard plastic to make a pan underneath my procooler runs; just to tidy things up as this can be seen and is not hidden. The plastic provided for the stone guards I use at work all the time. It can be molded very easily with the use of a heat gun. I may use this stuff for a skid plate over the front cross run so I can mold it around the hose, then bend a U clamp shape around the procooler side to cover the wheel-well portion that sticks out.

Cars at the mech now getting a fresh clutch so should be a little while before I get back on it to finish things up. I just wanted to get the mass of the work done while the weather is still nice here.

I see one less line in your ProCooler hose jungle than mine. Do you have a front bumper condenser - could not find the year of your car but may have missed it.

[CatSkynr]

Originally Posted by mthomas58

I see one less line in your ProCooler hose jungle than mine. Do you have a front bumper condenser - could not find the year of your car but may have missed it.

My car does not have the front condenser. It’s a 77 S.

Plus the pics do not show the hi-side running from the rear condenser to drier. That was the last thing I ran. You can see the c-clamp where it is to go. It is just along-side the rest running up. The dirty hose is the gas filler overflow.

[mthomas58]

Woo hoo! It's 70 and cloudy today and I was running on the Interstate earlier today. Tested Max Cool setting and med fan speed to see what she would do. Got vent temps down to 24 degrees!!!! Pretty impressive for 134a in a 911 IMO

[Mike Andrew]

I just hope to come close to mid 30's at the end of this project. I am truly impressed with those numbers. Cold enough to keep food & drink cold.

[mthomas58]

I'm ready for summer! Picture is a little dark - 23 degrees vent temp! In garage, 75 degrees ambient, max cold, med fan speed & engine at 2000 rpm.



Re-cap of new, four condenser system:

OEM tube and fin rear deck condenser with 3 spal fans
New barrier hose
Duehl Kuehl fan assisted fender condensers (2)
Kuehl Serpentine Evaporator
1/4" foam insulated and foil wrapped evap box
Kuehl Serpentine front condenser
Kuehl Variable Speed Fan Controller
RennAire ProCooler
Rebuilt Nippondenso Compressor
Converted to 134a

[CatSkynr]

Finished. I connected everything up and did a 24hr static nitrogen pressure test at 175lbs. I used my oil injector with the nitrogen and put in 10 ounces of mineral oil and a slug of dye. Next day I evac'd for 3 hrs and charged everything up. At ~80deg ambient sitting in the garage I got cold enough for the compressor to cycle when it hits 32 deg. Average is 35deg, so we'll see how it works when in gets in the triple digits.

[PSJoyce]

Me too. Nothing like nice weather to finish off this project that was inspired by this thread.

Living on Cape Cod, I didn’t need to improve the system too much, but I did need to take care of a very leaky compressor. New Kuehl center vent, serpentine front condenser, hi-low switch hose, receiver-dryer and rebuilt compressor. Followed Grif’s excellent instructions, flushed and vacuumed for a total of six hours (held vac at -29” Hg for over two hours) and a careful charge with 134a. Vent temps at 37° on a 75° day.

All in all, a satisfying project. I still plan to seal up the evaporator box.

Thanks for all the great information – I would not have attempted this without the great help here.

Paul

[bonaturtle]

subbed, want to do this for the summer as well, or have my shop do it I mean

[mthomas58]

Originally Posted by tsuter

96F Sunday 103F at the condenser gave 32F at the vents on high fan speed and temp dial at about 80-85%. I'm expecting a 70-75F differential when its 110-115F. Over 40F vents at any ambient would be disappointing. We'll see.

But I am interested in compressor temps. Not sure what they should run at. I may be a bit low on charge.

I played golf the other day. Ambient temp was high 80's and car was parked in ths sun and heat soaked for 5 hours. I was getting 43 to 45 degree vent temps and thought those #'s were a little high. Consulted with Griff and he agreed. At 7oz of oil he thinks I'm 1 oz overcharged which might be impacting performance. He suggests dumping out 1 oz of oil and recharging with 36 oz of 134a using a 30 lb container and a scale. My system continues to work GREAT. I'm going to continue to chart my vent temps and ambients and wait till temps get in the 90's before doing the evac, oil removal and recharge.

[mtbguy]

I can't wait to finish mine- I have all of the parts on hand now and am building my "Jim Sims" subcooler presently- hopefully I will be able to do the AC install in the next week or two.

Good job to those with these low vent temps!

[Mike Andrew]

I have virtually everything plumbed in except the TXV & condensor connections to the Procooler which I will do just before evac. & charge. However, I hit a snag with compressor pulley interference and am awaiting a compressor with a turned down pulley from Rennnaire. So, I am still in limbo.

[CatSkynr]

Well we hit 90s yesterday. With the car sitting in the sun all day and a cockpit temp in the triples, it took about 5mins and the vent was blowing 38. What I find amazing is that the condensers don’t get hot! (after ~45 minutes driving in-town) I can literally lay my hand on the deck lid condenser and it’s just warm, compared to the old York days. Same with the wheel-well; although I can’t really lay my hand on it due to space, to the finger touch they are just warm. The compressor definitely gets hot. The pro-cooler is cold and you can feel a temperature differential between the inlet and outlet of the low-side into the sub-cooler. So far I am really happy. As screwed up as it sounds, I can’t wait for a day of triple digits to really test this system out.

[PSJoyce]

Well, sometimes it’s the simple things.

Checking the vent temperature -- while the front trunk lid was open -- to make sure I hadn’t ruined something new while re-sealing the evaporator box to replace all the foam that had gone to dust, I noticed I could see daylight through the center dash A/C vent. Somewhere along the way in the last 24 years, the duct to the center vent had slipped off the vent. Reaching around from the front, but mostly reaching in through the clock hole, I was able push the vent back into place. I had always wondered why it didn’t seem like a lot of air was coming through the vent – much better now.

Paul

[Wickd89]

Man, you guys are awesome!

My '89 needs a new compressor and evaporator; after a professional inspection. They actually said everything else was fine (sure)...

I would love to do this full project but lack the time and/or $$.

Any Pelican experts in Socal that want to do this as a side project on my car someday? Great project for someone out of work or retired that has major skills!!

Since I have a Cab, this is a low priority project, but would be really nice...

[GH85Carrera]

A/C work is not difficult. You can do the vast majority of it yourself. The only part that is above the average home mechanic is the vacuum & charging. Hire a pro for that part if you don't have the knowledge & equipment. It all comes down to how much COLD air is worth to you.

[hcoles]

That's what I plan to do but where is there a very good AC shop that knows the older (e.g. 1989) Porsches and follows all the evac and charge proceedures mentioned in this thread and others... in northern CA or do I need to drive to LA to get the fricken thing done correctly?