This is the hottest summer we've had in Charlotte since i got my car in Dec 03.....And i have to say this is the first I've noticed how crappy the A/C is in this car. Sitting at a stop light, it blows semi cool air then as you get going it blows colder air. I dred sitting at stop lights.....Its been looked at and the dealer says everything is ok. Man, I hate it!!!!!

 

my car is stock. I have measured the AC output. with 96*F degree outside temp, i changed the settings to get the coldest air possible I have found that while sitting at a stop light (not moving) the car will put out 45*F air with the temp **** set full cold, fan at speed 3 and the inside/outside setting to recircutale (reuse inside air) and the blower set to upper dash vents only. with these same settings and same outside temp but now having the car moving at 50MPH+ the air temp coming out of the dash is 39*F.

Then I wraped the AC lines (all that I could find) with the tubing for home AC that they sell at home depot (black foam inside with reflective foil outside). I found that with the same settings used above witht he same outside air temp (96*F) that the air coming out of the vents when stoped was down to 43*F and when moving at 50MPH+ was at 38*F.

Then I treated the AC system with ICE32 (a coolant addative) and had the coolant 'toped off' and with the same setting and same outside temp when sitting still it was 41*F and when moving at 50MPH+ was at 34*F.

even though the AC only puts out air now that is 4*F cooler sitting still and 5*F cooler when moving 50MPH+ it makes a noticable difference. all for a total investment of about 60 bucks and a few hours.

On a hot day when you first get in the car it still takes a few mins to get the inside cooled off, but once it is, it stays cooler.

 

^Very impressive KYLiquid!^
All is fine, but what about the humidity level and time of day?

 

Wow, Mine never seems to get below 54 deg F. I tried the pipe insulation DYI, that (to my surprise) made no difference. Today, it was about 90, and although the air felt cold (did not have my temp probe hooked up) it just seemed overwhelmed by the sun beating sown. Onc I got the car into the shade, the cabin cooled off quickly.

 

I would give you a 1on1 tutorial of air conditioningand why its doing what its doing but I'm being lazy.

 

i think it's that tis car needs a MUCH bigger compressor or longer duty cycle or it needs a bigger fan.

 

I too was disappointed in RX8's cooling system. Now with my S2K, I literally freeze myself. I can't ever put it more then half way on fan speed, even on the hottest of days. It's simply coming out ice cold 100% of time, with no change at all in air temperature, not to mention an extremely powerful fan. Best A/C system I've ever owned no doubt, and I've owned many cars. Actually it's overkill with top up, but works perfect when you wanna go topless and it's hot out, because you can cool yourself off in traffic. I'm glad some of you were able to make it better, but Mazda should address this, and fix it in future models, because there's no excuse for someone having to do all those mods on a brand new 30k car just to make it comfortable.

 

this was a typical central FL day. the outside temp I made a reference to was what the cars AMB temp display said, after I had been driving for a few mins. (it always reads hotter sitting still than moving. I think it was reading 103*F when i first got in the car.

Anyway, humidity on that day was supposed to be around 80-85%. I started this little project at around 1230p and was done at around 200p. So durring the hottest part of the day around here. I also continued to test on the same roads. Same part of town.

Ive never been disapointed by anything in the car, maby im one of the lucky ones? But the AC was one of the things I could have been happyer about, and now I am.

Some people talk about the AC turning on and off? even when its set to be on....when i have mine running (moving or sitting still) it keeps pumping out the same * air temp non-stop.

 

i think the problem lies in the capacity of the cooling system, not the blower, i found that when I had the blower set to MAX speed (4) it had warmer air coming out than on speed 3, I think that the blower moves enough air that it was pulling the 'cool' out of the AC system faster than it could put it back.

 

Just a warning, I wanted to insulate my AC pipes and was told by a AC specialist (he works in a AC and Rad specialty shop) no to insulate the pipes. He has seen many vehicles with AC insulated pipes rotting out. He says the pipes do sweat and get wet, when they are insulated the water stays there and eventually rots the pipes. I don't know if it will be the case with the RX8 but that made me wait for a while.

 

tint should help a lot in keeping the heat out and let our wonderfully semi-cool A/C work more efficiently :o

 

the tint does help quite a bit, i have 15% all around and i put one of those 'reflective' shields in the front window when i park for a long itme in the sun

 

Ky, did you install the ice32 yourself? Which ice did you use? The one that comes in the freon recharge can or the one that comes in the small 1.5 oz liquid bottle? How much did you pay for it? Swoope and I are going to experiment with the ice next week. He already bought another additive, quick-boost.

 

so we are still on???

this should be fun. i need dates and times.

beers

 

I got that heat wrap that is insulated and reflective on the other side. I tie wrapped it to the A/C tubing on the firewall and got much better performance from the A/C. I'm in South GA and believe me, summers are much worse here. I grew up in Charlotte and I still visit there to see family, it's much worse here. Try that and see if it helps.

 

I insulated the horizontal part and left the part that bends down open to help drain the moisture out.

 

I followed Legokcen's lead. He suggested the wrap & ties to me. However I used the thick black rubber you get at any hardware store instead of the thin type. I've been very pleased with the output of my A/C. 3 passengers in the car today and 2 miles down the road everyone was satisfied with the temp. Tomorrow will be a big test as the weatherman mentioned 95+ degrees and 95 here is like 182 anywhere else because of the humidity.

 

I pm'd you.

 

Your not suppose to use that cheap stuff at Home Depot. The stuff for houses won't work correctly.

You need the good stuff from Porterfield or any shop that sells insulation for Drag racers.

I left my bottom tube unwrapped. Your AC specialist doesn't know about rotary's and piston engine applications.

Check any auto and you will see the tube on top being covered. The rotary produces twice as much heat. Corroding a Aluminum tube. I don't think so. Not with our heat. By the way it would take years for corrison to make a hole in that tube.

 

Can someone confirm if they too have less CFM air coming from the left-center vent than the right-center vent. Mine is noticeably less.

 

Yes. I noticed this as well in my Mazda 6.

 

Texas here...I got the TSB done for the A/C amplifier. At 106 degrees yesterday, it is hard to cool a car, no matter what you are driving, but after driving a Mazda 3 and 6 as loaners for a week...the 8's A/C works awesome.

My biggest problem with the A/C is that I refuse to set it to both upper and lower vents because it decreases the airflow SIGNIFICANTLY. The only way that it works well is with all the airflow coming out of the upper vents on recirc. I too have found that 3 is a better setting than 4.

 

^^ Agree. Having it on both vents just makes the car worse IMO. The sun beaming through the windows and windshield makes my upper body significantly warmer than my lower, so I only set the upper vents.

I left for a trip on Friday around 5pm, easily over 100 degrees. We had the air on 4 for 20 minutes before it was cool enough to turn it down to 3. Had it there for 30 minutes and then on 2 for a few hours. I don't think we had it on 1 until the sun went down.

 

The lower vents also include the vents for the rear seats (located under the front seats). So when you set the vents to both upper and lower you're also sharing the air with the rear seats. That's why the air flow decreases so much.

 

Recently had a Firestone dealer add Ice32 for $65. Figured WTH. I had already done the tube wrap DIY using some some 1" wide fiberglass tape wrap "borrowed" from the job site used to insulate steam tubing. Also have tinted windows all around. The measurements taken by the Firestone tech (at the top center vent) were as follows: 50 deg F car sitting still, set to outside air, fan set on 3. After Ice32: 45 deg F same conditions. So running down the road set to recirc, fan on 2 it's getting down to 40 deg F or lower. The real kicker is that it cools down a LOT quicker. It is bigtime hot and humid here. This stuff is not snake oil IMO. There is a noticable difference.

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