Just a random cooling question

[trickyrix]

I've seen/heard a lot of folks talk about the underperformance of the stock Miata cooling system. I've had cars in the past that were REALLY inadequate, but I've never had a problem with my Little Car - and I've put mine through a Dallas summer as well as a brutal New Mexico desert road trip in July. So is this cooling thing something I have to look forward to? Is there a weak point in the system?

Part of the reason I ask is that my old BMW had some sort of weak point and I never was able to fix it, even after $1,500 worth of Easter-Egging the problem. The other part of the reason I ask is that I'm getting reasonably close to throwing down for a blower - well, ok, I'm mere months away, but still.

I know Gary recommends a high-capacity radiator, and I'm on board with that, but are there deeper issues I need to be aware of? Do I need to flush my motor with CLR or something? But seriously, is there something I need to look out for?






Is that CLR girl hot or what?

"Now you've got a shower you can get wet in."

"All kinds of dirty, one kind of clean."

[Titus]

If you install an intercooler in front of the radiator, it heats up the air before it goes through the radiator. This makes things extra hard on the cooling system. Add an A/C condenser and things keep getting worse. Adding a bigger radiator helps. Adding ducting to maximize the air going through the radiator (rather than escaping around it) helps. Some still have problems. I have all of the above, and I still have problems in stop and go traffic when it is over 90 out and the A/C on. I have never heard of anyone having any more problems once they have added a pair of high CFM fans. One of these days, I will go that way.

[trickyrix]

If you install an intercooler in front of the radiator, it heats up the air before it goes through the radiator. This makes things extra hard on the cooling system. Add an A/C condenser and things keep getting worse. Adding a bigger radiator helps. Adding ducting to maximize the air going through the radiator (rather than escaping around it) helps. Some still have problems. I have all of the above, and I still have problems in stop and go traffic when it is over 90 out and the A/C on. I have never heard of anyone having any more problems once they have added a pair of high CFM fans. One of these days, I will go that way.

Good info... but I've heard of folks having problems with stock NA motors... I guess I'm one of the proud, lucky few? I see where you're getting your heat from, though... makes perfect sense.

[Nexus Flux]

Can I use CLR to clean out my radiator?
No, CLR should not be used on a car radiator for two reasons. First, CLR may not be compatible with the internal metals of the radiator. Second, it could have adverse effects if the CLR is not rinsed out completely.

Maybe you should stick to good old radiator flush.

[trackdog]

The 90-97 Miatas have really poor air movement coming into the radiator. Probably about 30% of the air is lost through opennings. The 99-05 Miatas are improved, but still has looses. When it comes to heat sources the A/C core generates more heat than our TDR intercooler and has more square surface area in front of the radiator. This is why most Miatas run hot with the A/C on. Probably about 30% of our TDR intercooler customers still use the stock radiator so being intercooled is a small percentage of the efficiency lose.

The stock fans, wired in parallel provide more than enough air flow and I would never consider recommending replacing them. The best thing you can do to improve efficiency would be to do the following.

1) Wire fans in parallel

2) Close off as many holes as you can (TDR sell a rad shield for the 90-97 models that mounts on top) You can use 2" aluminum foil with adhesive backing that you can get from the hardware store, it is used for A/C ducts and is waterproof.

3) Change the thermostat to either the 160F or 180F models (we stock both and prefer the 180F if you drive your car a lot in the winter and don't want to change it, the 160F is perfect for summer, but to low for winter)

4) Use 70-30 percent with anti-freeze and distilled water.

5) Cut the side panels off of your belly pan to allow more air to be pulled out of the engine bay area. On the 90-97, mark from the inside where the radiator ends and then remove the belly pan. Cut the almost verticle line you marked down to about 1" from the bottom and then cut the rest of the side off. On the 99-05 models, remove the belly pan and cut the complete sides off about 1" from the bottom. Tin-Snips work good for cutting this plastic.

6) If you are not boiling water out of your overfill bottle then running 225-230F is not considered overheating. Most every car out there runs this hot in the summer with the A/C on.

Hope this helps.

Gary

[trickyrix]

The 90-97 Miatas have really poor air movement coming into the radiator. Probably about 30% of the air is lost through opennings. The 99-05 Miatas are improved, but still has looses. When it comes to heat sources the A/C core generates more heat than our TDR intercooler and has more square surface area in front of the radiator. This is why most Miatas run hot with the A/C on. Probably about 30% of our TDR intercooler customers still use the stock radiator so being intercooled is a small percentage of the efficiency lose.

The stock fans, wired in parallel provide more than enough air flow and I would never consider recommending replacing them. The best thing you can do to improve efficiency would be to do the following.

1) Wire fans in parallel

2) Close off as many holes as you can (TDR sell a rad shield for the 90-97 models that mounts on top) You can use 2" aluminum foil with adhesive backing that you can get from the hardware store, it is used for A/C ducts and is waterproof.

3) Change the thermostat to either the 160F or 180F models (we stock both and prefer the 180F if you drive your car a lot in the winter and don't want to change it, the 160F is perfect for summer, but to low for winter)

4) Use 70-30 percent with anti-freeze and distilled water.

5) Cut the side panels off of your belly pan to allow more air to be pulled out of the engine bay area. On the 90-97, mark from the inside where the radiator ends and then remove the belly pan. Cut the almost verticle line you marked down to about 1" from the bottom and then cut the rest of the side off. On the 99-05 models, remove the belly pan and cut the complete sides off about 1" from the bottom. Tin-Snips work good for cutting this plastic.

6) If you are not boiling water out of your overfill bottle then running 225-230F is not considered overheating. Most every car out there runs this hot in the summer with the A/C on.

Hope this helps.

Gary

Yep... I'll keep this all in mind as I "summerize" my car.