I just noticed that when I have my a/c on, my water temp is in the 80-85C range, and normally it's 90-100C (100-110C at idle). Is it my imagination or is the a/c keeping the temp down? can anyone confirm? (of course, this is only for those with any gauge other than the stock. I have a 60mm greddy.)

 

Are you on the cold or hot side of the A/C? Do the radiator fans come on?

 

I'm on the cold side, and the fans do come on at around 110C (which I think is normal)

 

I belive this is becasue turning on the A/c also causes the fans to come on which will drop your temp.

 

make sense. on hot days, turning on the a/c will serve a dual purpose: cooling me and the engine off.

 

Dunno 'bout that.. on super-heated days with the A/C and fans on high, temps rise due to the compressor load in stop and go traffic. A few of use can attest to that from last summer's early-September heat-wave in Cali, and we had a few concerned posts. The stock "idiot needle" alarmingly went above horizontal.

 

I'll keep the a/c on as long as it appears to be doing some good, otherwise, off it goes

lucky me. my fd is a weekend driver only in good whether. hope the stop-n-go thing never happens to me. I already had a greddy 60mm temp gauge installed after doing my homework about the stock gauge. thanks for the info

 

No, a heater will cool the engine off.
AC can actually heat the engine up because of 2 things.
The engine has another accessory on it running, more work.
The AC is taking the hot air and expelling it to the atmosphere via
the condensor.

The reason his car runs cooler is because the AC turns the fans onto high.

 

BAM! exactly what I said

So, I'm tihnking, the best thing to do when the temp is starting to rise is turn the A/c on but turn the temp **** so its blowing out heat right? Well, other then turning off the car that is.

 

It has to do with ambient temperature and heat soak. If your engine is hot and/or the air temp is hot, turning on the A/C will increase the engine temperature. Your fans are probably already on high, then the A/C turning on will not increase the fan speed. The air passes through the condenser and heats up, then passes through the radiator at a higher temperature. If you are already hot and running the fans fast, the cooling of the fluid in the radiator is reduced due to the increase in the initial temperature .

If you are not running hot or hard on a cool or fair day, turning the A/C on kicks on the fans faster and causes an increased air flow through the radiator. Even with the increase in air temp due to the condensor as it passes through, the volume of air increase which reduces the fluid temperature overall more than the above example (more cooling capacity). The effect is that the fluid actually runs cooler than normal because the A/C is on.

Be careful when making universal decisions or statements as they can be untrue or true depending on the circumstances. As you can see, each example shows the results differently with the same act, but with different circumstances (initial temperatures and ambient surroundings)

Tim

 

this recent thread has better ways to run cooler, w/o using ac to get fans on.

https://www.rx7club.com/forum/showth...threadid=55903