Help design my a/c hose routing
 

1980, converting to 134, need all new hoses.
I have an underbelly, decklid and front condenser.
Will not be switching to any new brands. all of the condensers/evaporator/compressor are in good shape. Only moving hoses.

I hoped to just repair the hoses I have, but it turns out that the system that the PO put in about 10 years ago was NOT barrier hoses, like I thought (the crimps run along the hose, not perpendicular to it). So, need all new hoses, which is fine (some are damaged, some are old, some are going to be too short, etc, so wwest, you can keep your "barrier hose is useless" stuff to yourself).

I would consider adding a handbuilt condenser in the front driver's wheelwell. Don't exactly want to, but would consider it.

So, give me some ideas. The current routing is compressor-underbelly-decklid-front-dryer-evaporator-compressor.

Options I've considered:
1) underbelly-decklid-front
2) decklid-underbelly-front
3) REVERSE THE GAS
4) add a wheelwell, go underbelly-wheelwell-front and delete the decklid
5) add a wheelwell and go all out, decklid-underbelly-wheelwell-front

Or, delete the front and add a wheelwell, which opens up a future IROC bumper or oilcooler or something.

I'll be making all my own hoses and doing my own charging, so some experimenting is an option. SOME experimenting, mind you...

Oh, lordy. You're just asking for it aren't you? :)

I would think Option 2 would be the shortest in terms of hose routing.

Having recently pulled new hoses, one thing to keep in mind is that you just want to make sure you maintain ground clearance.

Has your system worked at all since you've owned it? If so, would you say that the cooling capacity was sufficient? That should give you some general indication of whether you need to increase condenser surface area or not. Then next things to consider would be the effect of increasing evaporator surface area and fan speed.

Now that the pin has been pulled on this grenade, I'll take a step out of the blast radius. ;)

6) eliminate the underbelly... subject to debris and radiant roadbed heat, add the fender well blower/fan. Front fender most desireable, only radiant heat source would be the tire, and you could run the fan(s) from a thermostatic switch on the R/D just as Porsche did with some models.

My only direct experience with the underbelly condenser is having purchased a '79 Targa in Salt Lake. A/C thermostatic switch had failed and upon repair I was advised that the belly condenser had been bypassed.

Contacted the PO who said the underbelly condenser seemed to work fine in NJ where he lived previously, but was advised that the poor performance in SL was due to the lack of efficiency of the underbelly condenser.

He said that after bypassing the underbelly condenser he felt the A/C worked better.

If it is true that the belly condenser is no longer available there might be good reason.


NJ vs Ut..???:confused::confused:

I'd say option 1, which in essence is very similar to "reverse the gas" since you are not dumping all the heat in the decklid and the engine. Keep your current setup if you are happy with the cooling it provides. If your compressor is in good shape you will only need to replace the R/D.
Can you share pics of your underbelly setup? How is it protected from the road debris (guard, etc...)?

If you want to take Mr. Wests' advice and get rid of the underbelly, I'll be more than happy to take it off your hands. Every car I've ridden in that had it, had excellent a/c.

The underbelly condenser stays, the car had frighteningly cold air the first summer I owned it, but a mistake with the fitting on the compressor blew all of the freon out one day. Hasn't worked since, haven't put any effort into making it work.

The setup now involves loading the underbelly first, which will take heat soaking away from the engine bay, but involves probably 10 extra feet of hose. Not a huge deal, but something to think about. I daily drive the car, but i'm on surface streets in basic 30mph traffic, not stuck in gridlock. I know the underbelly is worthless when sitting still in Houston, but that rarely happens to me.

Do i need a new fender condenser? no, but if that could/would allow me to remove the decklid one, then it's probably well worth it. I have seen people mention running a fender system and removing the decklid stuff, but no actual reports of anything doing that (as a retrofit on an older car, of course).


Currently the underbelly has basically no protection(well 2 1/8th in straps that hold it in place). The fins are thick and after 10-12 years show no damage. Car is at Euro height.



I will probably stick with current route (belly-decklid-front). It's not the shortest run, but the routing is there now to follow, and any strain taken off of the engine temps is worth it.


Oh, I'll likely toss a fan in the decklid, because there's room and it won't hurt.

I Have an underbelly unit, I've been looking at using it for years and still haven't installed it but will. I've read soooo many good testimonials with it that I just want to use it. BTW if you've ever seen one you'll see that it's not that vulnerable. It's stout to say the least. The fins are thick, the lines are also thick. The whole thing can take a rock hit and keep pressure by the look of it.
But, the fender units with fans make perfect sense and the latest AC thread that hoteuro shows only one decklid condenser system shows that three condenser systems are silly. Get a good condenser or two and be done with it. The hoses you're replacing will go a long way too.
I'm pulling for you, I'd bet you'll have a great system once all buttoned up.
I'll be watching this one with interest unless it gets too heated and if that happens, I'll just do like I always do and hide in the turbo/930 section for a while.

Mike If you can, please post a pic of that underbelly, how big is it? And...
If at some time it was "frighteningly cold" then it sounds like you answered your own question.

With making up new AC hoses, there are the newer, smaller diameter barrier AC hoses available. You are most likely aware of them, but if not, they are a lot smaller diameter and much easier to run thru the chassis. I had some new barrier hoses made up for my
car at a local industrial hose/fittings company, unfortunatley they didn't inform me of the smaller hoses till mine were already made up. Drat the luck!!

I won't let this thread become a CF. I will make sure to have Red-Dot brand trinary switches on both ends of the car feeding their respective Spal fans. I will not drive without removing the heat soak from the passenger area by opening all windows first. I will get the darkest legal tint for my sunglasses. I will crystallize the windows with heat rejecting crystals. I will remember that I am an uneducated redneck Texan

They are an option, at least the the reduced #8 hose is. It uses the same crimping dies as the normal #6 hose, so I thought I might use normal #6, reduced #8 and a single run of normal #10. Instead of buying extra dies at $70 each.

I will say that the reduced hoses are only about 20-25% smaller, and since I'm replacing good old fashion R12 hoses, the routing shouldn't be much of a problem.

Given that the "first in line" belly condenser obviously works so well for you I wouldn't hesitate adding a condenser/fan in the front(***) of the rear wheelwell and remove the rear lid condenser once the new configuration has proven itself.

On the other hand if you should add the fender mounted condenser/fan it might be wisest to make the new, more efficient (forced air cooling)condenser/fan "first in line".

Short hose runs to boot.

*** The radiant heat from the exhaust/engine/catalyst may well be so minimal that it only has a 5-10% negative effect but why bother since the alternative is readily available.

Here are two. http://forums.pelicanparts.com/uploa...1436819717.jpg

OK... someone has to say it...

http://www.sweetcitycandy.com/blog/w...tinmybelly.png

I actually wanted to go into the front of the front wheelwell, where the washer bottle is. That way, the flow path would be very direct, compressor-underbelly-fender-front-dryer-evaporator. The hoses would "mirror" the oil lines under the edge of the car.

I've also been looking at bulkhead fittings for A/C o-ring fittings, and wondering if there is any routing that might be easier going through the frunk...

Mine looks like the one of the left. About 3/4 thick total, with the shield endcaps like that. It runs almost to the oil lines left-right, and, what, 18 inches front to back?

These are identical just one is turned around

Forced perspective made the one of the right look about twice as thick.

I wonder why they quit making them? The sheer size of them makes up for any inefficiency. The ones I've seen look like they are steel. Is that so?
I think it was Performance Aire that sold them.

Not sure why they quit but I wouldn't want one because I don't need anything hanging any lower below the car. Seems like road debris and snagging on speedbumps is a possible downside.

Yeah that's the one I worry about. Will need even more care to navigate.

"why they quit..."

Didn't even come close to solving the MAJOR shortcoming of the factory system.

That was/is the lack of adequate refrigerant condensing efficiency with engine RPMs consistently low.

Obviously not every owner will encounter this problem but enough do that makes a condenser/fan addition a much more suitable purchase.

I would think that body twist/ torsion would be one reason they quit making them. Other than placing them on the roof like a 18 wheeler reefer, underbelly seems ideal from a theoretical standpoint.

I would go with the shortest hose routing possible. You're talking about a LOT of GD hose any way you look at it.

http://forums.pelicanparts.com/uploa...1436880213.jpg
http://forums.pelicanparts.com/uploa...1436880230.jpg
http://forums.pelicanparts.com/uploa...1436880244.jpg

It's held in place by the straps, so no real torsional problems. Obviously I've deleted the rocker panels, but they might hang almost that low themselves.
As you can see, for a daily driver, there is no obvious damage from speed bumps or anything, it hangs about as low as the front cross member.

EDIT: There is one more hose on the passenger side. So, compressor-underbelly hose is pass side, underbelly-decklid is driver's side, decklid-front is driver's side (passes through that shield on the end of the underbelly unit), then on to the dryer and evaporator. Although, it looks like it might go to the dryer before the front condenser, I'll have to check that more carefully.

Great pics Mike, for us who had never seen such a thing....one comment, its HUGE. Looks like side skirts will totally cover it from the sides.
But watch out running over things, I just clipped with the right front what I think was a 6 inch piece of a 2x4, what a loud BANG, right under the passengers feet, dented the floor! I was going 65.
Sh... happens.

Update:
I received my hose and most of the fittings and went to work this weekend.

1) Decided to go with the underbelly condenser first

2) Decided that the hose between the rear condenser and the front condenser would be #6 hose, with a #6 and a #8 fitting. The factory setup is a #8 hose with a #6 and a #8 fitting. Reason I went smaller was 2 fold...I had the extra #6 hose but not the extra #8 hose, and the factory used the larger hose because the system wasn't yet liquid after only one condenser, while my system that hose is after two main condensers, so the refrigerant should be partly/mostly liquid at that point, so the smaller diameter would work.

3) Went with all o-ring fittings, using flare-oring adapters in a few places.

4) Little known fact...Sanden compressors have replaceable and interchangeable backs. So, don't use adapters or weird fittings or kludged togehter piping to get your ports to work, just buy a back that has the accessories and attachments you want! $25-30, 10 minutes to swap it out, and you have exactly what you need! also helpful if you bung up the aluminum threads...

5) Making A/C hoses at home is FUN and EASY and CHEAP. The 3 foot hose between the compressor and rear condenser? The one people tell you to change when going to R134? The new one that has the binary switch included? I can build that hose for $30 (custom, with the switch mounted, custom length, custom fitting selection). The vendors that sell that hose? $150+ (no custom length, no custom fitting selection). Why buy new??


http://forums.pelicanparts.com/uploa...1440424514.jpg

This is what 60 feet (60 FEET!!) of hose looks like. I removed everything to check all equipment, check hose lengths and fitting orientation, and generally get a sense of the whole system. This is my routing, I will follow it with the new stuff.



So, at the end of the weekend I have the hoses 90% complete and installed (I need 3 fittings still). I am also making stubby hoses that can replace the dryer and expansion valve, so I can do a complete system purge and flush at once (one inlet, one outlet, flushing all hose and all flushable parts).


All said and done:
25 feet of #6 hose (used 25 feet)
25 feet of #8 hose (used 20 feet)
15 feet of #10 hose (used 13 feet)

$336 shipped for the hose, all fittings including the male fittings for my stubby hoses, and adapters. $167 for the crimper. So, $500 for completely custom hoses, with a few extra inches on each one to help with routing, full freedom of fitting clocking, etc.

Nice pic Mike, man that's a lot of hose.....you know minivans use Al tubing but that's a moot point.
You have already made the hoses just like the pic, I see, but that dumps the heat under your feet first.
You could have gone front, tail , center (less heat to the floor) or front, center, tail (less heat to the engine).
Any particular reason for choosing what you had, besides it WORKED.

Take the load off the engine as much as possible.
I don't think that the front condenser is up to the task of being the first in line, AND it's built with #6 lines and fittings, while the rear condenser is built with #8 fittings. Clearly, the guts are different, and the front one should be last in line.
I could have gone with new custom condensers, but these are in fine shape.
I could have gone (and might in the future) with a wheel well setup in the front driver's side, removing the front factory piece all together. This could be done with just cutting and recrimping the hoses, since the inlet/outlet to the front condenser travel through that wheel well anyways.

First off, don't bother replying to wwest, it only encourages him to take the thread OT and aggrandize himself. Best to ignore him, or to invite him to start a new thread to discuss his pet theories. Onto the meat:

I think you are correct about the front condenser. If you wanted to take the heat load off the engine, I'd suggest the rear fender condenser. Since there are off-the-shelf solutions, that would be the most simple choice. I would route the hoses so that the fender condenser is first in line, then the belly, R/D, evap, compressor. This would also reduce some of your hose run. Delete the front and decklid condensers. If you wanted to go really nuts, dual fender condensers. Also and off-the-shelf solution. Finally, do not give a passing thought to radiant heat issues from the road or the exhaust. The effect is so vanishingly small (especially from the road, LOL) as to lack meaning. OAT is the big driver here, not any radiant heat source.

So close...so very close...http://forums.pelicanparts.com/uploa...1441635651.jpg


That was last night, hit it with a 60psi pressure test then pulled a 2.5 hour vacuum which reached 27 inches, sealed things up, and I'm about ready to go downstairs and see the 12 hour status.
I'll backfill with a can of R134 then pump for 4 hours, which will give me an OAT of 95ish to fill this afternoon.

I wanted to be here 24 hours ago, but learned that my rear condenser had 2 pinhole leaks as I tried to pressure test the entire system (Grrrrr.....). Figured I was down and out for at least 2 weeks and had a $500+ bill ahead of me, when I stumbled across an early single row decklid condenser for sale, just an hour away! Weeeeeeeeeeeeeee!!!

So, only delayed half a day not 2 weeks.

Nice work, and nice to have good luck. I guess we know where your refrigerant went, and again show that methodical testing, and not WAGs, are the way to troubleshoot these systems. Anyone who continues to listen to wwest should have their heads examined. OK, here's a totally OT question for you - your fan and shroud look fantastic - did you refinish those yourself?

under belly
 

Hi, would you mind telling me whose brand of barrier hose that you used? I see that their are quite a few brands out there. I've read that Duponts are very good.

BTW, are the condensers that you used from the rear trunk of a 911 or are they a special item?... Last but not least; how in the end did it work out for you? Like 'cold'?

Thanks in advance!

Finally getting around to answering things in this thread!
First off, I did not have A/C until last night.
Secondly, the hoses are a mix of Galaxy and Parker, I ordered bulk from ColdHose, and they sent two different brands.

The rear condenser is an early 911 part from a '77. It's a single layer of coils, instead of 2 layers likes the SC and later condensers. I'm not concerned about that for 2 reasons, one because it makes the condenser thinner and it cleared my coil better and second because the underbelly condenser is the primary one, so a smaller thinner secondary in my engine bay is just fine.

So, system was charged and running on September 10th. On September 11th, the system was completely empty. Slow leak somewhere, no oil dripping to follow.

Fast forward to this weekend (the first chance I've had to get under the hood). Since then I bought:
a replacement receiver dryer (the cheaper $35ish one, fits just fine)
30 pounds of DuPont R134a (from Pepboys, they had it in stock and a 30% off coupon, was $150 after taxes)
A few extra fittings to make jumpers for the expansion valve and receiver drier (for flushing)

So, set up the system so I could do a 100% flush at once...remove R/D and expansion valve, place jumpers in their place, disconnect at compressor, run a drain line from the #8 fitting to a bucket. Flush using a flush gun into the #12 line. I ran a full gallon of flush through, and that setup flushes every single line and condenser all at once.

Blew out the lines with compressed CO2 until dry.

Pull a vacuum for ~1 hour. Backflush with R134a to static pressure (~80psi). Note hissing sound.

So, my evaporator had a #12 flare fitting and a #8 o-ring fitting, which I thought was strange. I assumed that when the PO had the A/C upgraded, that the shop brazed an o-ring end on the factory evaporator. So, since I went all o-rings on the hoses, I needed a #12 flare to o-ring adapter placed there.

Hissing was coming from that fitting. vented (oh, I mean, recovered) the static load of R134 in the lines, cracked that fitting apart to examine it...and found that in fact my evaporator had a #12 o-ring fitting with a o-ring to flare fitting on it. It was so crushed together that it appeared to be a solid end, but in fact was one of those little adapters in there. So, I actually had: male o-ring/o-ring to flare adapter/flare to o-ring adapter/female o-ring hose setup...
Peeled that off, cleaned out the crunchy o-ring that was crushed in there, put a fresh #12 o-ring on the now o-ring male fitting, and ran my o-ring female hose right to it.

Pulled a new vacuum, backfilled with a static charge of R134a, repeat 2 more times.

Remove expansion valve and receiver drier jumpers and install expansion valve and new drier.

Change vacuum oil

Pull a hard vacuum for 2 hours. Backflush with R134 static charge. Pull another vacuum for 1 hour.

Prepare to fill.
I picked up a 50 pound capable digital scale for $18 on Amazon. Checking it out, I find that it is precise if not accurate. That means, I put my can of R134a on there over and over and get within 0.2 ounces each time. Press down on it and let go, goes back to within 0.2 ounces. Pull up and let go, same deal. So, for differential weighing like we're doing, it will be perfect. I don't care if the can is 30 vs 30.75 pounds, I care that when it says its 30 ounces lighter, that it is.

Car specs: Sanden S508, all new hoses. Routed compressor/underbelly condenser/decklid condenser/front condenser. About 58 feet of hose. Stock evaporator. Wirbelsturm evaporator fan (so, higher air speed than stock). Some extra insulation of the evaporator housing, etc. Some sort of upgraded bowtie center vent.

R134a can on scale, connect to gauge set, flush yellow hose of air.
494 ounces total for the can.
Open gauges, fill system with static charge.
488 ounces 86psi, OAT 98 degree. Car has been sitting in the sun for 2 hours, as has the R134 tank.

Start car, close decklid, box fan on decklid. doors wide open, full fan, full cold. I have temp probes reading the ambient air at the dashboard, one in the inlet for the evaporator, and one at the vent outlet.
Open blue gauge fitting.

474 ounces (differential 20 ounces). 26/235psi
468 ounces (differential 26 ounces). 30/275psi Inlet air temp 95, outlet air temp 65
464 ounces (differential 30 ounces). 28/295psi Inlet air temp 94, outlet air temp 61
456 ounces (differential 38 ounces). 33/325psi Inlet air temp 93, outlet air temp 61
Started venting (oh, I mean, recovering) by cracking the blue hose fitting. don't know ounces vented.

first dropped to 29/310psi, then to 28/305psi. That gave me a 93-59 inlet outlet temp. Should be about 31, 32 ounces?


So, I noticed (and it was like this a month ago as well) that my low side never gets above 35ish. I see numbers more like 55 for OAT of 95-100. Why can't I get that high? Is lower better? The high side will happily increase with increasing charge, I went to 325 and stopped.
Am I too low right now at 28/305, OAT 98ish? Or too high?


Sealed everything up and grabbed a beer. Left car in garage (well heat soaked!), doors closed, windows closed.


Start car, windows closed, full max speed and cooling. Drive to work on 30ish MPH roads with normal stop and go traffic.
7:41am Dash temp 86 degrees, inlet temp 83 degrees, outlet temp 86 degrees
7:45am Dash temp 84 degrees, inlet temp 74 degrees, outlet temp 51 degrees
8:08am Dash temp 71 degrees, inlet temp 62 degrees, outlet temp 42 degrees. System was cycling at that point.

I'll get a good highway speed check done in the next few days. I expect that the system will excel when the car can move at a consistent 40mph or more.


WEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!

under belly
 

Thanks for all the info!... Much appreciated .