For those with upgraded AC systems, what should typical vent temps be?

[Rawknees'Turbo]

Originally Posted by Jonny H

^ mid 80s would be a pressure of ~40 PSI corresponding to a boiling point of ~45F. So pretty much exactly your readings.

Normal cars seem to adhere to the rules of the Universe.

Everyone has their limitations, but some are at a far lower bar than others!

[Bob Kontak]

Originally Posted by Rawknees'Turbo

Everyone has their limitations, but some are at a far lower bar than others!

One thing stays constant through all of this noise, Ronnie's meat locker.

[Rawknees'Turbo]

Originally Posted by T77911S

i have his evap and front and rear cond,.
40's maybe 50.
that's driving with fan on hi, BUT I have to turn the temp up because the evap will freeze over.

people will say they get down in the 30;s or even 20's but a proper system should never get that cold BCAUSE of the evap freezing over and the low side pressures can get too low.
the 911 does not monitor the low side like most cars do, they just use an evap temp probe to "control the low side" not the best way to do it.
part of the reason you can get down to 30 is if you set the fan speed to low and/or the air flow over the evap is low, in part due to the low CFM out of the stock fan.

you also need airflow over the condensers to get proper or accurate temps.

My ASSessment of a proper a/c system is the opposite of yours - a system that is not capable of low 30s/high 20s in 90+ ambient, with the fan on max speed, and no evaporator freeze-up, is an underperformer that is in need of improvement.

Originally Posted by blucille

a lot of folks measure with an IR/laser infrared thermometer. It simply won't be accurate. Mine showed temps well below freezing, 20 degrees F at times. I used an instant read kitchen thermometer in the center dash vent.

. . .

How about when that IR thermometer takes readings of the passenger's seat (40-45 degrees) and headliner (50-55) on sunny, 96+ ambient with 70% + humidity, TexASS days - do you consider those temp readings inaccurate, as well? And what about when the IR thermometer reads the same as a digital probe style thermometer - just more BS temp data?

Originally Posted by JMS935

The better laughs are the guys stripping out their AC systems to save a few pounds with their puny N.A. motors. Those are the threads I find hilarious. To sacrifice all that comfort for what’s probably so negligible in added performance that you barely notice it if at all. At least they’ll lose weight sweating their asses off, so that’s another weight savings bonus as well.

Don't be so sure about that; the seat covers, foam, and in some cases, even the carpet (depending on the person's level of sweathoggery) will become so waterlogged and salt laden with the owner's, "look, I ditched that worthless, boat anchor system so my car can now accelerate a 100th of a second quicker on my way to Hooters, and looky how clean the engine bay appears now, too" approach to motoring, that the car will actually gain weight!

Originally Posted by Bob Kontak

One thing stays constant through all of this noise, Ronnie's meat locker.

That's the Mighty Meatlocker, Bobasaurous!!! Yer welcome!!!

[hcoles]

Originally Posted by walt

I have the full Griffith upgrade and can get sub 40 temps on a hot day with the middle fan speed. Using his improved performance evaporator fan the temps do increase slightly with the higher fan speed.

I also have the full (4 condensers) Griffiths setup on R134a. Everything new except the deck-lid condenser. The temps depending on fan speed (I have the Griffiths variable fan speed option) are usually 40-43F on hot days. Sometimes it goes down in the 30s. The car is comfortable on a 100F day.

[1979-930]

I have the Classic Auto Air full upgrade kit. I was seeing low 30* temps. But then the system started having issues and tuning off due to excessive high side pressure.
I need to get a new expansion valve from them. I tried Napa and we could not get the right one. Smugglers door would not close.
I lowered the pressures to where it would work and still get low 40* temps with insufficient freon on the system.
I think insulation in the smugglers box and sealing the blower panel in the evap case helps a lot. Especially on a 100* day.



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[T77911S]

Originally Posted by Rawknees'Turbo

My ASSessment of a proper a/c system is the opposite of yours - a system that is not capable of low 30s/high 20s in 90+ ambient, with the fan on max speed, and no evaporator freeze-up, is an underperformer that is in need of improvement.




How about when that IR thermometer takes readings of the passenger's seat (40-45 degrees) and headliner (50-55) on sunny, 96+ ambient with 70% + humidity, TexASS days - do you consider those temp readings inaccurate, as well? And what about when the IR thermometer reads the same as a digital probe style thermometer - just more BS temp data?




Don't be so sure about that; the seat covers, foam, and in some cases, even the carpet (depending on the person's level of sweathoggery) will become so waterlogged and salt laden with the owner's, "look, I ditched that worthless, boat anchor system so my car can now accelerate a 100th of a second quicker on my way to Hooters, and looky how clean the engine bay appears now, too" approach to motoring, that the car will actually gain weight!



That's the Mighty Meatlocker, Bobasaurous!!! Yer welcome!!!

pressures relate to temps.
the Porsche does a piss poor job of regulating the low side. yes you can get very very cold air out of the 911 because of this, BUT you risk the evap freezing up just as mine did. when the low side drops to 20 or less you are looking at temps in the 15 to 20 degree range which i have seen on the 911, including mine with an all new system. that's why most cars have a low pressure switch located on the low side that cuts out at around 20 to 24 psi. its to keep the evap from freezing.
maybe where some of these guys live that can run in the 20's don't have the humidity that we have on the east coast. yes i go out to the mid west and laugh when people complain of the humidity and its so dry "I" don't even sweat. yes i have to change my clothes several times a day if i am working outside at home.

i have been to a month long HVAC school. if your system is blowing below 35 something is not right.


for those that want to use the "magical" refrigerant that is colder than anything else do some research and find out what is in it. it usually has propane and/or other refrigerant, like r22.

its all about pressure= temp. if you want to try to tell me otherwise then you need to do some reading on it.


and yes my probe works, i have to turn the temp up to keep it from freezing. i do have the original fan. low airflow will also make the low side lower and the temps lower. IR thermometer i was in the 20's, i don't like them for that check.

calibrate mech thermometers in a glass of melting ice.