AirCon Rad to CC Query

[CarlC]

My car's never had aircon since I've bought it. Not a great fan anyway of aircon and I would rather have the roof off and windows down being a sunny day driver. Also my S4 requires the old type R413 gas .

So Im strongly considering switching the use of the rad to the CC (as per S300) and I have a couple of queries after studying the diagrams reading up on the aircon stuff. I also want to clear a few points up too?

1- Is there a direct gas replacement I can use to recharge my aircon without dicking about changing compressors, pipes for the enviromentally friendly stuff ?

2- On the combined Aircon/CC rad, am I right in believing the rear rad is for the air con ?

3- Looking at the parts manual for the S300 CC rad setup surely it would be more efficent to avoid the use of the T junctions on the flow and return to join the front and rear rads and instead have 1 continuous flow through both rads. This would maintain steady pressure right through the system rather than dropping pressure at the T which allows cc coolant to flow through the Aircon rad?

4- If I ever want to re-instate the aircon rad would I have caused any permenent damadge ?

Any responses greatly recieved.

[docf]

2- On the combined Aircon/CC rad, am I right in believing the rear rad is for the air con ?

3- Looking at the parts manual for the S300 CC rad setup surely it would be more efficent to avoid the use of the T junctions on the flow and return to join the front and rear rads and instead have 1 continuous flow through both rads. This would maintain steady pressure right through the system rather than dropping pressure at the T which allows cc coolant to flow through the Aircon rad?

4- If I ever want to re-instate the aircon rad would I have caused any permenent damadge ?

Any responses greatly recieved.

2 - yes

3 - i have mine connected in serial (flows from front cooler -> rear cooler -> motor). I dont see real world advantages in efficiency with this setup but seeing as how the 2 rads are different sizes and sit differently connecting them in parallel would result in uneven flow the the 2 rads.

4 - it aluminum so just have take it to a rad shop to flush and pressure test.. should not cause any permanent damage.

[docf]

one more thing.. make sure you have the ac condensor flushed and pressure tested before you connect it to the CC. I flushed it with 25 gallons of water mixed with assorted solvents before it the water started coming out clear. The oily residue that the AC system leaves behind is very nasty stuff and really stings bad when it accidentaly sprays all over your face.

[CarlC]

Thank you Doc.

Good tip on on the flushing of nasty chemicals before spraying coolant on to face.

Edited September 2, 2006 by CarlC

[Loose Cannon]

I may be regurgitating horseshit here, but I remember reading a post where one guy just refilled his aircon system with the new type gas. This was on the advice of two pals of his who were in the industry, who said that whatever seals may or may not be damaged by the new stuff are what you would replace in a rebuild anyway, so who cares? They had done this to several of their own systems and were still waiting for the first failure.

Always made me wonder that one, I suppose the only analogy is running an old engine on unleaded instead of doing a head conversion.

[Artie]

I may be regurgitating horseshit here, but I remember reading a post where one guy just refilled his aircon system with the new type gas. This was on the advice of two pals of his who were in the industry, who said that whatever seals may or may not be damaged by the new stuff are what you would replace in a rebuild anyway, so who cares? They had done this to several of their own systems and were still waiting for the first failure.

Always made me wonder that one, I suppose the only analogy is running an old engine on unleaded instead of doing a head conversion.

Carl,

I'm not sure what R413 is but my 89 came with R12(old cfc type freon). It was barely working, I evacuated the old aircon system of the little R12 left and recharged with R134a freon. I did this back in March and stays nice and cool still. That being said, the aircon system isn't really designed for such a large cockpit. The blower motor is LOUD and underpowered and my knee still has frostbite! I didn't change any components or change seals, just flushed and recharged.

Artie

[CarlC]

Oh crap!

Now I cant work ut what to do. I want the bigger rad for the CC. But If I can get the air working for the sake of a

[Artie]

Oh crap!

Now I cant work ut what to do. I want the bigger rad for the CC. But If I can get the air working for the sake of a

[Loose Cannon]

Thinking more on your problem, surely the benefit of doubling the radiator size will only be worthwhile if you fit a PUK enlarged chargecooler and high capacity electric pump (more $$$$).

I am sure there are still companies who will recharge with the old gas (at least one on the South Coast openly advertises it, maybe look in a classic car mag), although not running it since you bought it does not bode well for the condition of the seals.

[CarlC]

Hi Mark,

I already have the WC Eng. Hi Flow Electric pump. My problem is that the fins on the front Rad were mashed and had to be removed to allow airflow to the rear engine rad. This means although I do get cooling of the cc its not as effiecient as it should be.

I havent run the aircon since purchase as its never worked since I bought it. I suspect it hasnt worked for some time previous to my purchase given the general condition of the car when I bought it.

So im not really doing this as an upgrade but more of making the best of what I have and use. I will at some point in the future replace the cc/aircon rad but given its pretty large cost at

[Evil_Dr_Fish]

iirc You won't necesaarily ONLY get an improvement with the addition of a bigger CC... any extra cooling - ie if the second rad results in cooler water - will result in an improvement, as you will still get a cooler, denser charge

[Artie]

Right! Simple thermodynamics really. If you substantially increase the surface area of the cooling/heat exchanger(by adding in the a/c rad) you will NOT need to add a larger CC, the second rad. will dissapate the heat better as the CC heats up and will perform even better noticeably when you are really "kicking it". If you don't really get HOT days, this would be a good option. I didn't realize the A/C hadn't worked in some time as the seals are probably dried out so I'd definitely pressure test if before you recharge it! BTW, Carl, I haven't had time to plumb the second CC pump in to my system yet. I did get the Johnson pump for my second pump. I hooked it up to power and it is LOUD!

Artie

Hi Mark,

I already have the WC Eng. Hi Flow Electric pump. My problem is that the fins on the front Rad were mashed and had to be removed to allow airflow to the rear engine rad. This means although I do get cooling of the cc its not as effiecient as it should be.

I havent run the aircon since purchase as its never worked since I bought it. I suspect it hasnt worked for some time previous to my purchase given the general condition of the car when I bought it.

So im not really doing this as an upgrade but more of making the best of what I have and use. I will at some point in the future replace the cc/aircon rad but given its pretty large cost at

[CarlC]

Thanks for the confirmation of the effect of adding the second rad. I really dont hold out much hope for the Aircon but i will get it pressure tested before attempting any recharge. To be honest Im secretly hopeing it does leak so I can plumb the aircon rad in series with cc rad.

So the Johnson pump is loud. I take it Art that is in comparison to the WC Eng pump. Maybe it will be quieter when its full of water, assuming you tried it without pumping water through it?

Being much louder is the flow rate any higher than the WC Pump ?

Very interested to see how this turns out Art. Keep us posted on your little project. B)

[Htown]

If I may throw in my .02 cents...

Replacing the condensor assembly with a proper radiator for the CC, would provide even greater cooling capabilty in the chargecooler system. The condensor was designed to change the physical state of freon, not designed to be efficient at cooling fluid. A radiator is a much more efficient and lighter way to cool fluid. Same principal applies on Intercooler core design and flow-path. Picking the right core for the job is the key.

Sure, the combined cooling ability of both halves of the condensor assembly is better than the factory setup, but if you are going to ditch the AC anyway... why not just sell off the compressor, condensor, drier, lines etc... any install a real radiator to do the job. Lightwieght, better cooling, and a few bucks in your pocket...

fwiw-

Craig

90SE

[Artie]

Thanks for the confirmation of the effect of adding the second rad. I really dont hold out much hope for the Aircon but i will get it pressure tested before attempting any recharge. To be honest Im secretly hopeing it does leak so I can plumb the aircon rad in series with cc rad.

So the Johnson pump is loud. I take it Art that is in comparison to the WC Eng pump. Maybe it will be quieter when its full of water, assuming you tried it without pumping water through it?

Being much louder is the flow rate any higher than the WC Pump ?

Very interested to see how this turns out Art. Keep us posted on your little project. B)

Carl,

Well, I was pumping water, not coolant and water, I was testing the pressure of the pump. The rating is similar to the WC pump but it seems that it may pump more and with some head pressure. The head pressure is rated at .15 bar which is 2.8psi, which I'm hoping is enough to push more coolant thru my core. I'll plumb the johnson pump right before the core to push some more fluid at a better rate as the WC pump is WAAAYYYY back under the charcoal canister. John at WC told me that some of his track cars run 2 pumps in series with great result. If this second pump doesn't give me a decent result I'll have to reevaluate my CC rad core and possibly have an entirely different design made to my specs(although this one to my specs doesn't seem to be going so well). My IAT's are maxing about 43C which according to John these should be around 35 or 36C.

Art