3.6 A/C Upgrade

[brads911sc]

Woo hoo. We graduated from google to Wikipedia.

[GH85Carrera]

Originally Posted by SilberUrS6

OK, I've been a little sarcastic in this thread,. but let me be completely serious for a moment.

I have written installation instructions for automotive parts before. More than once. I have taken pictures, and offered helpful hints.

Kuehl's instructions are better than what I wrote. If I were to find fault, it would be ONLY that there are fewer photos than I would like. Now, this is personal preference - the written instructions are so comprehensive that *photos are not necessary.* Let me repeat this. You could install the GTI stuff without any reference photos. Easily.

This is unprecedented in the aftermarket industry, IME. Most folks work on the hardware, sell it, and expect the customer and his mechanic to figure stuff out. Not Charlie. He sells you good stuff, then writes excellent instructions AND then holds your hand over the phone.

None of the stupid lies that wwest tells will change that. You want quality product, excellent support and true DIY? Even for the mechanically shy? Spend some money and go with Griff.

Want to waste money and wish you had listened to me in the first place? Take wwest's advice.

I have to agree the instructions and supplied parts list is without a doubt the best of anything I have ever seen. Top quality materials and parts.

Removing the old hoses is indeed a dirty job. I have done other dirty jobs that were worse. The final results of the system is just as advertised. I can make my wife cold on a hot summer day in my 1985 911 now. I just dial the temp knob up and she is happy. She did want to ride in the car with stock AC because she would get hot.

[wwest]

Originally Posted by Barrpete

1. The proper equation is Q = UA ΔTm

2. No.

And the "U" value of water vs gas (R-134a) is....?

From what I could find the CONDUCTIVE heat transfer factor for water = 0.61, for air = 0.026. Since the refrigerant gas operates under low side pressure the molecular density would be greater than "free" air so the factor would rise but by not nearly enough to get even close to equaling water.

[kuehl]

Willy,

Let's ignore, for the moment, the subject of latent heat.

Instead, assume you want to compare the performance of ...say, an oil cooler.

You have 3 different oil coolers.
You test each one using oil in the same manner.
Each cooler provided you with different results.

How would summarize the results?

[wwest]

Originally Posted by kuehl

Willy,

Let's ignore, for the moment, the subject of latent heat.

Instead, assume you want to compare the performance of ...say, an oil cooler.

You have 3 different oil coolers.
You test each one using oil in the same manner.
Each cooler provided you with different results.

How would summarize the results?

I'll assume forced air on the "other" side.

Assuming the oil is the same medium to be used in actual operation, I would summerize just as you did.

On the other hand if I tested with oil (machine oil "U" = 0.15) where the final medium used would be water ("U" = 0.58) I would summerize with an adjusted ratio (3.86:1), heat transfer charactoristics of the oil I used for testing vs that of water.

http://www.roymech.co.uk/Related/Thermos/Thermos_HeatTransfer.html

[kuehl]

Originally Posted by wwest

I'll assume forced air on the "other" side.

Well, I'm not clear on what that means, the 'other' side'.
You could use a fan on either side of the oil cooler.

Originally Posted by wwest

Assuming the oil is the same medium to be used in actual operation, I would summerize (SP = summarize) just as you did.

"You test each one using oil in the same manner. " Yes. Using oil.
And the context here is motor cooling naturally. So you can pick out
the weight, type and brand.

Originally Posted by wwest

I would summerize with an adjusted ratio (3.86:1), heat transfer charactoristics (SP characteristics) of the oil I used for testing vs that of water.

Well, the issue with testing refrigerant components is not only precise metering of the refrigerant (less than a gram), but a precise vacuum as well. The later requires ionization gauges, hot or cold cathode type, because the common higher end AC vacuum gauges reading in microns or pascals or whatever scale you choose won't cut it or comparative testing.

So, let's say you had your 3 engine oil coolers tested on the same test rig using the same procedures (environment, oil type and weight, air flow, oil flow, ambient, etc.). And, one of the 3 outperformed another by 10%.
Would you say that was: an achievement, respectable, acceptable, or so-so. ?

[wwest]

Originally Posted by kuehl

Well, I'm not clear on what that means, the 'other' side'.
You could use a fan on either side of the oil cooler.

Assumption: There is a (metal) "wall" between the oil and the air (on the "other" side) to which you wish to convey the heat....


"You test each one using oil in the same manner. " Yes. Using oil.
And the context here is motor cooling naturally. So you can pick out
the weight, type and brand.

It doesn't matter provided the same oil is used in the test and the final application.


Well, the issue with testing refrigerant components is not only precise metering of the refrigerant (less than a gram), but a precise vacuum as well. The later requires ionization gauges, hot or cold cathode type, because the common higher end AC vacuum gauges reading in microns or pascals or whatever scale you choose won't cut it or comparative testing.

Basically BS.

You could use the same basic test procedure using an operational A/C system that assures a constant availability of liquid refrigerant at the TXV inlet. Give the TXV enough time to stabilize and then measure downside, downstream airflow temperature, 100F in, xxxF out.

So, let's say you had your 3 engine oil coolers tested on the same test rig using the same procedures (environment, oil type and weight, air flow, oil flow, ambient, etc.). And, one of the 3 outperformed another by 10%.
Would you say that was: an achievement, respectable, acceptable, or so-so. ?

But what if you tested the oil cooler using water instead of the oil to be used in the final environment....???

Wouldn't you then have to adjust the results to compensate for the differences in the heat transfer coefficient of "the" oil vs water..?

If in your case if the water gave a delta, improvement of ~40%, then adjusted accordingly, 3.85:1, the net would be an acceptable 10%

[brads911sc]

A 10% difference is still a 10% difference. Wake up Willy. Early bird special get your brain in a fog?

[wwest]

Originally Posted by brads911sc

A 10% difference is still a 10% difference. Wake up Willy. Early bird special get your brain in a fog?

Best leave the response to Kuehl, he seems to understand the subject matter....

[kuehl]

Let's try this one more time Will:

1) "You test each one using oil in the same manner. " Using oil (not water, not
refrigerant). And the context here is motor cooling naturally. So you can pick out
the weight, type and brand.

2) One of the 3 outperformed another by 10%.
Would you say that was: an achievement, respectable, acceptable, or so-so. ?

[brads911sc]

Because you have no clue? Ok. Thanks

Quote de brads911sc

A 10% difference is still a 10% difference. Wake up Willy. Early bird special get your brain in a fog?

Best leave the response to Kuehl, he seems to understand the subject matter....

[SilberUrS6]

Originally Posted by kuehl

Willy,

Let's ignore, for the moment, the subject of latent heat.

Instead, assume you want to compare the performance of ...say, an oil cooler.

You have 3 different oil coolers.
You test each one using oil in the same manner.
Each cooler provided you with different results.

How would summarize the results?

You did notice the change of subject and the picking of nits?

He's looking for ANYTHING to get out of the corner he's painted himself into - the one where if you test three different components in the same manner, the differences between the components manifest themselves.

OK, I will pick a nit. Water is very viscous in comparison to any gas. So heat exchange could be affected. So, use a less-viscous fluid, but one with very-well-known physical properties. Like methanol. Or a very low-boiling solvent like pentane or dichloromethane. Low viscosity, low boiling point, low heat capacity.

My prediction is that the results will be slightly different. But not much. still close enough to 10% to be able to say "close enough".

And I would suggest that in the world of similar components, especially in the automotive realm, a 10% increase in function is pretty damn great. Automakers fight for fractions of a percent. On everything.

[SilberUrS6]

Originally Posted by brads911sc

Because you have no clue? Ok. Thanks

This is the correct answer.

[wwest]

Originally Posted by kuehl

Let's try this one more time Will:

1) "You test each one using oil in the same manner. " Using oil (not water, not
refrigerant). And the context here is motor cooling naturally. So you can pick out
the weight, type and brand.

2) One of the 3 outperformed another by 10%.
Would you say that was: an achievement, respectable, acceptable, or so-so. ?

Acceptable but it would still need to be reasonably priced vs the other 2.

And then there is the case with an improvement, is the rest of the system, thermostat, etc, capable of allowing me to make use of that extra 10%? Suppose my thermostat never has need to open beyond 70%...?

[wwest]

Originally Posted by SilberUrS6

You did notice the change of subject and the picking of nits?

He's looking for ANYTHING to get out of the corner he's painted himself into - the one where if you test three different components in the same manner, the differences between the components manifest themselves.

OK, I will pick a nit. Water is very viscous in comparison to any gas. So heat exchange could be affected. So, use a less-viscous fluid, but one with very-well-known physical properties. Like methanol. Or a very low-boiling solvent like pentane or dichloromethane. Low viscosity, low boiling point, low heat capacity.

My prediction

Sounds like a speculative prediction to me...

is that the results will be slightly different. But not much. still close enough to 10% to be able to say "close enough".

Why speculate...? Why not look up the heat transfer coefficient for your chosen test medium vs air/gas...??

And I would suggest that in the world of similar components, especially in the automotive realm, a 10% increase in function is pretty damn great.

In the case at hand we're talking 24,000 BTU's of cooling capacity for $300.00 vs 26,400 BTU's for TWICE the price, $600.00. And no way of knowing if the bench test numbers using water vs air/gas are really valid.

Along with a GREAT deal of uncertainty as to whether even the hurricane blower can "squeeze" that much cooled airflow through the flow restrictor, restriction.

Does no good to take a 400 HP engine to a race if the rules dictate that you must limit to 300 HP using an air flow restriction plate.

Not to raise the question of the well known and widely acknowledged MAJOR shortcoming of our factory A/C, an adequate supply of liquid refrigerant at the TXV inlet to support even 24000 BTU's.

Automakers fight for fractions of a percent. On everything.

No, automakers fight for fractions of a CENT. On everything.

[kuehl]

Mr West.

Thank you for addressing the questions with your opinions.
Your opinions are naturally predicated upon your experiences,
your needs and your desires.

When it comes to AC cooling "performance gains",
in most of these threads, the member(s) asking the question(s) are in need of
significant improvements as compared to stock systems; they are not driving
their 911/930 in summer temperatures that average below 85F, on the contrary
they are in the 90's and 100's. It is a known fact that the stock system using R12
cannot provide the cooling comfort they wish for, because of various reasons:
condenser capacity, volume of air, distribution of air, etc.

In "your" opinion a 10% improvement in an engine oil cooler is acceptable
provided it is affordable. Granted. The rules of procurement are:
1) A product that meets the needs: fit, form, function and reliability.
2) A product that is available when you need it.
3) A product that is at a "just" price; this later point you seem to contest through out your thread posts. Ok, you have a nit pick with pricing. That is your opinion.

So, back to the example of the oil cooler proven to provide a 10% lower return temperature as compared to stock and competitors. Who, other than yourself
would want this product? Naturally it is the owner of a car whom is need of that
10% gain because they actually need it. Is it affordable to them? In their opinion it might be. In your opinion for yourself it is not, probably because you do not need it.
However to tell or attempt to convince a reader on the forum that it is overpriced
or "snake oil" in your terms, and then go on to offer alternative suggestions that have not worked, could not work, or have never been proven to work? Well, that is not sound advice. Some people enjoy finding alternative solutions (innovations). Some people enjoy bolting on a turn-key solution. And others don't have the time or desire and let others do the work. That is the nature of life. However you seem to wish that every reader in this forum must follow your path, your suggestions or travel down your road. Well, it seems that most do not wish to. That is their choice.

The cost of a product is usually relative to the factors of production: capital investment, R&D, and volume (supply and demand). One could easily argue that an add on board for a computer priced at $3500 is overpriced. One could also imply that a company in the computer business that is advertising products on their website and noting Call For Price sounds like a hypocritical Snake Oil company.

A reader posts that in their opinion that they 'predict' an outcome. And you respond
"Sounds like a speculative prediction to me...". Well, it reads to me that either you are speculating or being hypocritical.

A reader posts that in their opinion 10% is "close enough". And you respond
with an opinion to speculate with coefficient tables, however on the other hand you always demand test methods and data, yet you yourself have not presented the same; you want others to do your work.... why is that?

Your opinions/arguments, examples such as "the case at hand we're talking 24,000 BTU's of cooling capacity vs. 26,400 BTU's" or "uncertainty as to whether even the hurricane blower can "squeeze" that much cooled airflow through the flow restrictor, restriction." , appears to me like speculation, you have not proved anything to the contrary.

A statement like: "a 400 HP engine to a race if the rules dictate that you must limit to 300 HP using an air flow restriction plate." , does not make logical sense. If you had a 300 hp engine with a restrictor plate and you upped it to 400 hp, you still have more air moving through the plate. I experienced with is my supercharger this year, as well as others with their turbo's.

All of your rants to me, my products, my company, as well as other members of the Pelican community, seem to imply you do have a personal jihad.
Your jihad reduces your creditability in this forum.

[brads911sc]

Sounds like wwest needs be banned.

[Bob Kontak]

Originally Posted by brads911sc

Sounds like wwest needs be banned.

How is this done as moderators appear to be absent.

[tirwin]

Originally Posted by wwest

Acceptable but it would still need to be reasonably priced vs the other 2.

And then there is the case with an improvement, is the rest of the system, thermostat, etc, capable of allowing me to make use of that extra 10%? Suppose my thermostat never has need to open beyond 70%...?

Based on your opinion, a 10% performance improvement over the competition is worth what? A 10% price premium?

[brads911sc]

Pelican Parts - Product Information: 901-573-907-00-OEM

Stock is $807.

How is $600 overpriced? Seems to me that you get a 10% improvement for 25% less.

Seems like a good deal to me...

Wwest logic is quite interesting...