You are misinformed and a little paranoid.

If you are routinely running that hot, you took the right steps in getting a rad, but also check to make sure you don't have air bubbles in the coolant and run some water wetter.

Rotaries run hot in general you can't expect the motor to behave like a piston engine.

 

I have this exact same problem!!! I have the following cooling mods....koyo radiator, aluminum ast, stock intercooler, pfc w/ datalogit to turn fans on earlier, dp,mp,catback, intake. My temps on an average day sits around 88 driving around and at a light it will go up to 90 and 91 on hot days. But as soon as I turn on the air conditioning the temps start to rise until it hits 99 and then I shut the air conditioning down, after turning the ac off the temps will eventually drop back down to the normal 88-91 temps. So what is the problem or what is the temps suppose to be at on the pfc with the ac on? I have the fans set with the datalogit to turn on at 90c.

 

Get rid of the Water Temp meter and your problem goes away...

 

I made adjustments to my fan settings and the highest that they got up to today in traffic was 96c . I will keep these settings throughout the week to see if they really work. I will let you guys know.

 

for putting around in hot traffic, ac on, vented hood will not help coolant temps very much.

with stock 180F/82C t-stat, max cooling happens when warm-up bypass loop is closed by wide open t-stat, which is at/above 195F/91C at t-stat. good control logic would have max fans come on at about 7C higher, 208F/98C at t-stat hsg. this keeps bypass closed during hot traffic+ac cooling cycle.

check list, assuming healthy engine, all air purged from coolant:

1) t-stat opens wide by 195F

2) system holds pressure ( implies healthy caps)

3) rad is sealed, so hot exhaust air from fans doesn't loop back to front of rad.

4) rad core has no internal deposits

5) ac properly charged, verified by pressure check.

6) water pump not underdriven by pretty pulleys. this is a road-track only reliability mod. the slowed pump will be too slow in traffic, and allow even well cooled coolant to heat up more than it should by the time it lazes through the block.

7) fans hit max (3rd) speed. need pfc, fan mod switch, or miata switch to be sure high speed happens by 92-97C.

8) 50/50 ratio assures min 224F boiling with no pressure, and reliable operaton at 100C/212F. As fans cycle, coolant pressure can be very low as coolant temp drops.

9) for smic, consider fans and shroud on IC, relayed off cooling fans. this prevents hot air exiting rads from looping back to nose through the IC. also reduces IC heat soak.

10) alum ast should have .07" pill in one of the 2 main hoses, to reduce rad bypass flow.

11) for florida/texas, add ball valve in the heater core return line, near wp housing. cam showed me his, pettit may sell them.

anytime flow bypasses the rad, cooling efficency suffers, esp at low rpms:
- the rad is always bypassed by the heater core.
- alum ast's w/o oem restrictor bypass rad when t-stat opens
- attemps to conrol temps too close to 190F will open the warm-up bypass.
- TB line is a semi bypass, and could use a pill to reduce flow rate.

 

*UPDATE* With my new adjustments made to the fan setting which is....fan1 cuts on at 91 and fan2 cuts on at 92. With this new setup the temps stay at 96c in traffic until today. It was during stop and go traffic when the temps hit 98c. When this occured I turned the ac off and the temps creeped up to 100c-101c. After riding for about five minutes the temps began to drop from 100c to 87c. Also out of curiousity and not to change the subject by any means....when I hit 100-101c on the PFC (wiht ac on) do I run a risk of blowing out the coolant seals or am I more likely to lose a coolant seal when I am running at these temps for 4-5 minutes? The car has hit these temps twice while driving down the road. And another question is if I do get a vented hood (considering due to heat issues....unless you guys think these temps are normal and I am being paranoid) what happens if it rains??? Is it ok? I am planning to get the hood from rotaryextreme. Thanks for all the info and hopefully this will get resolved.

 

If you see 115 C, then start worrying.

 

Mahjik is that what you personally think is the time I should start to worry is when the temps hit 115c. Or is that what the manual says? Also does the manual state what temps is normal when using the a/c? Thanks

 

In stock form, the fans don't come on until around 221F (about 105 C). Even then, that's not overheating. At 115 C (about 240 F), that's when you should wonder what's going on if you aren't pushing the car hard on a track).

 

Excuse my ignorance (again) guys, but why are the 4 blade fans better than the 5 blade fans? are the blades bigger? It seems to me that 5 would be better for moving air, but then again, I'm no engineer

 

This was discussed before and I believe the masses said it was for harmonic purposes. As two fans of the same type would create a droning/thumping type sound.

Keep in mind that there is more to CFM than just the number of blades on the fan.

 

what speed are your fans on? did you try making air ducts so that 100% of incomming air goes thru your radiator and not around it? you might wanna try to run a bit less coolant and more water and see if that helps.

btw: you are using only distilled water right?

as for the scoot/N1 hood, i would not really worry too much about the rain getting in, it would have to rain enough to flood the streets up past your engine and by then, your already fked

 

Interesting. I'm not gonna waste too many brain cycles on the 'why', I'll just nod my head in agreement with what has proven to work