A/C question. Performance Aire or back to stock with mods?

[Joeaksa]

Did a 3.6 conversion a few years ago, and the A/C compressor is off as all of the lines and condensors. Needed to replace the lines with barrier versions anyway. Summer is behind us so I have 9 months to get the A/C system working again.

I have a set of Performance Aire replacement "knee pad" vents and the underbody condensor that goes with them. Purchased them used several years ago but now am not sure that I want to go this route. The "knee pads" are full length vents that connect to the stock output vents and give you a lot more control over the cooled airflow.

To further muddy the water, also have some 1986 larger A/C vents (the 1985 models had pretty skinny vents on the outside) that could be modded to fit into my dash.

The more and more I think about it, am leaning towards putting one condensor in each left hand fender-well (front and rear) and tossing the nose mounted, and engine grill mounted condensor.

Anyone had any experience in this area and comments or suggestions?

Thx,

Joe A

[wwest]

Originally Posted by Joeaksa

Did a 3.6 conversion a few years ago, and the A/C compressor is off as all of the lines and condensors. Needed to replace the lines with barrier versions anyway. Summer is behind us so I have 9 months to get the A/C system working again.

I have a set of Performance Aire replacement "knee pad" vents and the underbody condensor that goes with them. Purchased them used several years ago but now am not sure that I want to go this route. The "knee pads" are full length vents that connect to the stock output vents and give you a lot more control over the cooled airflow.

To further muddy the water, also have some 1986 larger A/C vents (the 1985 models had pretty skinny vents on the outside) that could be modded to fit into my dash.

The more and more I think about it, am leaning towards putting one condensor in each left hand fender-well (front and rear) and tossing the nose mounted, and engine grill mounted condensor.

Anyone had any experience in this area and comments or suggestions?

Thx,

Joe A

IMPO the stock system, will/would/could, work perfectly fine with increased, sustainably increased, airflow over/through the engine deck lid condensor.

A rear spoiler provides a perfect mounting space for 4-6 small boxer type 12 volt brushless ball bearing computer cooling fans. 12 volts to each fan with the compressor clutch engaged, each 2 in series otherwise.

[Brillo]

I am running the underbody condenser and am underwhelmed by its performance All components have been updated to run with R134 BTW.

[Joeaksa]

Ray,

Do you have their underdash vents or are you using the stock vents? Did you drill the second hole to let more air in the cabin?

I will be running R-12 or a mix of R-12 and ES-12 to help with the cooling. Am not a fan of R-132 and it will never be in any A/C system I build. Its not a good gas and is the result of a kneejerk from the govt to the tree huggers.

West, thats exactly what I do not want to do, introduce more warm air into the engine compartment. Thats why one of the condensors will be in the fender, replacing the engine cover mounted condensor. Why put warm air from the condensor into the engine, when you are spending lot of $$ in oil coolers to keep the engine cool?

Thx,

Joe

[mppickett]

I'm running a 993 condenser in the drivers front fender well and kept the nose condenser. Works just fine (upgraded most other parts, though).

[Joe Bob]

Are you gonna DIY or have it done?

[RSTarga]

Id love to see how you mounted the 993 condensor. That is the real fix for our older cars. How did it fit? does it have a fan?

[wwest]

Originally Posted by Joeaksa

Ray,

Do you have their underdash vents or are you using the stock vents? Did you drill the second hole to let more air in the cabin?

I will be running R-12 or a mix of R-12 and ES-12 to help with the cooling. Am not a fan of R-132 and it will never be in any A/C system I build. Its not a good gas and is the result of a kneejerk from the govt to the tree huggers.

West, thats exactly what I do not want to do, introduce more warm air into the engine compartment. Thats why one of the condensors will be in the fender, replacing the engine cover mounted condensor. Why put warm air from the condensor into the engine, when you are spending lot of $$ in oil coolers to keep the engine cool?

Thx,

Joe

Joe,

As you may have already noted the A/C supplies enough cooling capacity with the engien RPM up and therefore the engine Blower SUCKING WARM AIR, lots of it, out/over the condensor and over the engine for its cooling. It's when the engine's RPM is NOT up that the A/C cooling capacity suffers. Obviously when the engine RPM is NOT UP it isn't burning very much fuel so there is little need for engine cooling.

It's even possible that my method would increase engine longivity. Having the engine cool down during idle periods and then reheat during power periods cannot be good for an air cooled engine. At least that was what I was taught regarding careful monitoring of the engine in our C210.

[Brillo]

Originally Posted by Joeaksa

Ray,

Do you have their underdash vents or are you using the stock vents? Did you drill the second hole to let more air in the cabin?

I will be running R-12 or a mix of R-12 and ES-12 to help with the cooling. Am not a fan of R-132 and it will never be in any A/C system I build. Its not a good gas and is the result of a kneejerk from the govt to the tree huggers.

West, thats exactly what I do not want to do, introduce more warm air into the engine compartment. Thats why one of the condensors will be in the fender, replacing the engine cover mounted condensor. Why put warm air from the condensor into the engine, when you are spending lot of $$ in oil coolers to keep the engine cool?

Thx,Joe

I am using the original (small) dash vents and the large underdash vents. I am not aware of the second hole. Where is that? I had this done, so I can ask if they did that.
There is plenty of air, it is just not able to keep up (cold enough) when the outside temp. gets much above 92 degrees F.

I totally agree with you on the R-12 vs. 134, if I had to do it over I would still be running the R-12. That's what's in my 1960 Caddy and it is just fine.

I agree with you on the rear condenser also. If I decide to do anything else, I would do what you are doing (remove rear condenser and put in a fender one).

Good luck & let us know how it turns out.

[Joeaksa]

Originally Posted by Joe Bob

Are you gonna DIY or have it done?

DIY. Frankly after what I have seen in the A/C world, this is not rocket science. I do the A/C on all my other cars and they work great. Problem is that I am not happy with the rear deck mounted condensor, and thinking that the newer style products are more effecient.

Joe

[Joeaksa]

Originally Posted by Brillo

I am using the original (small) dash vents and the large underdash vents. I am not aware of the second hole. Where is that? I had this done, so I can ask if they did that.
There is plenty of air, it is just not able to keep up (cold enough) when the outside temp. gets much above 92 degrees F.

I totally agree with you on the R-12 vs. 134, if I had to do it over I would still be running the R-12. That's what's in my 1960 Caddy and it is just fine.

I agree with you on the rear condenser also. If I decide to do anything else, I would do what you are doing (remove rear condenser and put in a fender one).

Good luck & let us know how it turns out.

Performance Aire had a mod that they drilled a second hole through the metal that provided more airflow. About the same size as the one "cool air outlet" but just doubles the volumn of air.

[Joeaksa]

Originally Posted by wwest

Joe,

As you may have already noted the A/C supplies enough cooling capacity with the engien RPM up and therefore the engine Blower SUCKING WARM AIR, lots of it, out/over the condensor and over the engine for its cooling. It's when the engine's RPM is NOT up that the A/C cooling capacity suffers. Obviously when the engine RPM is NOT UP it isn't burning very much fuel so there is little need for engine cooling.

It's even possible that my method would increase engine longivity. Having the engine cool down during idle periods and then reheat during power periods cannot be good for an air cooled engine. At least that was what I was taught regarding careful monitoring of the engine in our C210.

My issue with the engine grill mounted condensor is that its adding MORE warm air to the engine and IMHO thats the last thing that is needed. Would rather have the condensor in another area but thats me.

[Barrpete]

Originally Posted by Joeaksa

My issue with the engine grill mounted condensor is that its adding MORE warm air to the engine and IMHO thats the last thing that is needed. Would rather have the condensor in another area but thats me.

+1 on that. I used to have temp problems running the AC & idling in traffic until I installed a fan on the oil cooler.

I'm still toying with the idea of replacing the decklid condensor with something like the Griffiths dual rear fender condensor.

[GH85Carrera]

I can't say I have hard scientific evidence, but I do have my opinion on the extra condensers in the fender on engine temp.

I added the two fender condensers. Before the upgrade my engine temps in the summer would get pretty high. I had my system operating at peak stock performance. I was stuck in traffic and moving at 20 MPH, the A/C was pitiful and I was sweating and the engine temp was approaching 250.

That prompted the upgrade. The A/C now works. On my trip to San Diego driving through Phoenix AZ It was 110. The A/C was doing great and the engine temp was 200 to 210. I went up the mountain over the pass into San Diego and the engine temp never went above 210.

My bottom line, with 4 condensers the A/C works great I stay a lot cooler and the engine stays a lot cooler.

[Joeaksa]

Glen,

Are the fender condensors new or old style? I was told by the A/C place that a good single new style fender condensor would do the job of 2-3 of the older 911 factory versions.

I was as well going to put a 993 condensor in the front fender but after talking with them feel that its worth getting a newer version instead.

[Joe Bob]

Let me know how it works out.....may do the same thing.

[GH85Carrera]

I used the Griffith's system. His condensers are a little different than the factory condensers. I kept the factory rear and front condenser.

[Brillo]

Originally Posted by GH85Carrera

I can't say I have hard scientific evidence, but I do have my opinion on the extra condensers in the fender on engine temp.

I added the two fender condensers. Before the upgrade my engine temps in the summer would get pretty high. I had my system operating at peak stock performance. I was stuck in traffic and moving at 20 MPH, the A/C was pitiful and I was sweating and the engine temp was approaching 250.

That prompted the upgrade. The A/C now works. On my trip to San Diego driving through Phoenix AZ It was 110. The A/C was doing great and the engine temp was 200 to 210. I went up the mountain over the pass into San Diego and the engine temp never went above 210.

My bottom line, with 4 condensers the A/C works great I stay a lot cooler and the engine stays a lot cooler.

Interesting. My car tends to run hot as well.