before ducting, my car idled in traffic around 90* on average, but once i get on the highway cruising around 90mph, i would get up to 110*-112* (on my PFC, factory temp guage stays middle)....as soon as i pull off the highway, it cools back down to 90*ish.

FL summer heat sucks!

so my cooling system works well, but i figured that the radiator just wasnt getting proper airflow at higher speeds.

between my jobs, i dont have a whole lot of time to build a proper badass duct setup, so i had to slap something together quick just to see if it made a difference.
i used some 26guage aluminum sheets and tin snips to make a rough duct that guides air from the front intake to the radiator (no airflow comes from underneath at all now). because it was a rush job, it is not exactly airtight, there are quite a bit of gaps on the sides.

im amazed at the difference.

the car still idles around 88-90*....highest ive seen on the hottest day was 91* sitting in traffic.
on the highway, the temps now STAY at 89-90* max!!! even in the middle of the day.
thats a 20* difference with a leaking crappy duct!


one day id like to buy or have someone make a custom proper ducting system. does anyone sell something like that?

 

So you made a makeshift undertray? Of corse your temps went down...Thats what its there for.


John

 

The underbelly tray is there for a reason sir. Use it! :P

By the way, 110-112 on the PFC is WAY too hot! I get paranoid any time I even graze 100.

 

the previous owner must have lost/broke the undertray, there was never one there when i bought the car, so i had no idea it was a missing piece....that explains the hot temps! now they wont be a problem car has never overheated though....according to the FAQ my previous temps were still safe, and she runs great!

 

112 degrees is *way* too hot. When I road race my FD I start letting her cool down past 105.

I recommend purchasing the proper factory part that is proven to fit well and won't fly off on the highway. Call up Ray Crowe at Malloy Mazda at 888 533 3400

 

^ This! According to Dave @ KDR, if you even so much as touch 110 you'd better be pulling off the road/highway and letting your car cool down. I RARELY see over 100, unless it's an extremely hot day, I'm racing, and/or I'm running the A/C. :P

 

Put the proper parts back on the car and get a aftermarket rad. I have never got past 86 degrees and that's with a duct stealing air from the rad! I have mine setup to give air to my IC

That includes spirited highway/town driving.

 

I have no undertray and a FMIC i don't see about 90C cruzing on the freeway. When i had an undertray i didn't see above 85C. Hottest i've ever gotten was 98C.

 

Yes but you also have a SMIC. :P Get a FMIC and watch those temps climb!

Mine's not horrible though...On a warm day cruising down the highway @ 70 I fluctuate between 87 and 89 degrees.

 

Get an undertray. I didn't have one for the longest time either but I didnt' have a PFC or aftermarket Water Tmp gauge to see my exact temps. Once I got the PFC it showed that I was around where you are at 90c. With a Blitz FMIC, undertray, and Fluidyne radiator I see 86c max. I still need to rig up some better ducting on the sides of the IC and radiator to get proper airflow.

 

i made an oilc ooler duct last week. i guess ill make an undertray too. and a fmic/rad duct. ill post up later

 

I must be the exception here, no undertray or ducting and last summer/fall I would never see higher than 92, and once I switched my second fan to turn on at 85 also I never saw higher than 86. This is on an FMIC too.

 

If I were you I'd save the hassle and just fork out ~$130 to get a factory undertray. It will probably duct better than anything you can make and is plastic so it will absorb any impact you get from rocks or debris on the road. It is totally worth the money and not expensive.

 

ill look into it. I have a huge sheet of SS sheet metal I can use for the other ducting. i can probably find a used undetray cheap as dirt. regardless... i will be posting some sort of pictures/data

 

The local mazda dealership here wants over $200 for it. Where did you buys yours from?

 

Contact Ray at Malloy Mazda at 888 533 3400. His are around $150 IIRC, but shipping such a large item hurts. Typically when we order a new engine from him, I'll add in an undertray and a hood insulation blanket to help keep shipping costs down.

 

Curious, why is everyone so comfortable with posting temps in centigrade and not fahrenheit? Everytime I see temps posted in "C" I'm like WTF temp is that!


Edit: Thumbs down symble was an accident. Sorry!

 

Most people read temps off PFC and c* is what shows .

 

C'mon bud, you've posted in past threads about how smart and competent you are in all things rotary. I'm sure you can handle '9/5 +32'

 

google calculator is your friend

 

I too am the exception to the rule. With an undertray on my car, I run 7-10*C HOTTER than with it off the car. 3 rotor, FMIC, large oil coolers, with every sealed up front, the car runs no hotter than 93*C cruising and cools right down to 90*C when stopped in traffic.

WITH the undertray on, however, temps shoot up when cruising to around 100*C and are around 93*C when stopped. Just did the testing last week at Kilo in Orlando. Air temps outside were around 93*F and it was humid as hell but this gave me a worst case scenario to test the two setups. I was very surprised the undertray made the temps go up that much. So I ditched it and it is sitting now at Kilo. We decided to revisit this some later time but for now, no undertray for me.

 

The only reason they are posting temps in Celsius is because us Canadians are taking over the world. Soon you won't be using MPH or gallons muahahahaha.

Ok enough of that lol. Have you tried the 3rd gen section for a used under tray? Someone has to be parting out a vehicle with an under tray.

 

Or get yourself a big piece of plexiglass and do work son!

 

You guys don't know HEAT. My FD is around 120 just sitting in the garage with the engine OFF. Oh Yah, you guys are talking centigrade, not farenHeat. It is so hot here in Phoenix, the conversion formula here is "night-time temperature", then from 9 to 5 add 32 degrees. I took temperature readings with my infrared detector...120 in the garage, 140 on the concrete driveway, 155 on the asphalt paved street, at mid day with 110 degree air temperatures. The inside temperatures of the car range around 150-160 degrees parked in the sun. My wife uses oven mittens while driving around town, because the black steering wheel gets hot enough to actually burn your skin.

My problem is the airconditioner. It shuts off with boost and as temperatures rise under the hood. I was told that there is a sensor that cuts off the A/C under boost or high temperatures. Is there any way to disconnect that sensor, and would that be detrimental to the A/C compressor?

 

fixed