TRZ750

Any RX8 guys that complain about the AC should try a hybrid. I was in a Ford Escape hybrid the other hot day and complained to the owner to turn up the AC. He told me that that was one problem with the hybrid as the AC compressor runs of the gas engine and when in extended electric mode the AC doesn't cool!

As for the 8 I love, the engine turns from 800 rpm to 9,000 rpm. This had to be taken into account when installing AC as the compressor cannot handle excess speed. So there were two choices. One was to shut off the AC at high rpm, but this caused customer complaints at high speeds. The other was to have the compressor pulley ratio set so the compressor was not damaged by high speed. But this causes poor AC during extended idle times in rush hour traffic. So just rev your engine a little when needed. Everything is a compromise!

mysql101

There's other ways to do it, besides your two options listed.

I don't think anyone is complaining about AC cooling when driving non stop at 9000 rpm.

What people complain about is that the AC switches itself on and off repeatedly during it's normal operation.

MPG > HP

After owning, since 9/03 and 87500 miles, I'm surprised there is still no fix, factory or otherwise, for the premature A/C cycling problem. Anyone know where the A/C regulator thermostat is, so we might relocate it to a "warmer" location to fool the system into thinking it needs to be on longer?

As for the hybrid, I just took delivery on a Prius and the A/C is great. Unlike the Ford hybrid, the Toyota A/C runs off the main battery, so is always available. I ran it for quite a while when reading the manual and the IC motor turned on for a few minutes to recharge the battery, then just turned itself off. Pretty amazing technology! I'm still keeping the RX, though. Can't quite let myself out of the rotary world, after driving them exclusively, for over 20 years. Maybe I'll store it until a hydrogen fuel kit becomes availble and then outfit with an AFSC! (Btw, just learned that the hydrogen RX-8 can switch to gasoline on the fly, but needs to stop, before switching back to hydrogen.)

ken-x8

[QUOTE=MPG > HP]After owning, since 9/03 and 87500 miles, I'm surprised there is still no fix, factory or otherwise, for the premature A/C cycling problem. Anyone know where the A/C regulator thermostat is, so we might relocate it to a "warmer" location to fool the system into thinking it needs to be on longer?/QUOTE]

What about the AC amplifier replacement that's covered in a TSB? Was that supposed to fix the cycling problem, or was it for something else?

I've got an '06, which presumably has the new amplifier, and my AC is fine. At least it was for the upper-90s weather we had here in Virginia in August. Never had to switch to "recirculate" and don't think I needed to put the fan above 2 very often.

Ken

MPG > HP

Ken, Didn't mean to take the thread off topic, but I had the amp installed under the TSB over a year back, but it didn't help. I guess I'll have to jump into an '06 to see if the newer A/Cs are better. The only way I can get any semblance of A/C is to put recirc on and set the (really noisy) fan to 4. - Gary

mysql101

That doesn't mean it's not cycling.

Mine was built in 12/03, my AC has never had any issue with being cold. I can actually see the air coming out of my AC because it's so chilly. I rarely have it on anything other than 1.

With that said, my AC cycles on and off. There's no fix from mazda, they all do this. I think it's an emissions thing, or for fuel economy. If your AC is only on half the time, it saves in fuel or something.

Miker

Mine's a 07/05 build and while Toronto is not known for it's plastic-melting Nevada/Arizona heat, we've experienced a good summer with humid days up in the high 30's (celcius). I've never experienced a problem with the A/C. I do hear a thump or thud when the compressor turns on or off...but it's damn chilly at times.

ken-x8

There are two philosphies on regulating AC. One is "reheat", where it runs all the time, and temperature is regulated by mixing in hot air - running the heater if necessary.

Back in the energy crisis of the 70s, a lot of commercial building operators were surprised to learn that they used more power by turning the AC temperature up a few degrees.

The other is to cycle the compressor.

At the risk of sticking my neck out into ignorant speculation again, I wonder how many of the cooling problems are due to low refrigerant charge. I was surprised to see that the TSB for poor air conditioning does not include any of the standard tests for AC: check pressures, measure temperature coming out of the blower.

It's unfortunate that these cars don't have a sight glass in the AC system, either.

Ken

shahram72

My guess is that the charge is low from the factory. Almost all Ford F-150's come like that from the factory. I have one with 140K miles and at 130 I charged the AC, it cools better than it did when new. When it was new it cycled a lot and of course the dealer said it was "normal" I tell you I have almost no use for a warranty. Rarely does anything major fail on a car during the warranty and most of the little problems can never be replicated by the dealer anyway. I had a warranty on my Ford and Mazda, and really needed neither.