Need help. POS is overheating. Fans? Radiator? Set it on fire?
 

Ok, so ever since I've boosted my car it tends to run a bit warm. For the most part the only time I had actual trouble was in heavy traffic in 85+ degree weather with the a/c on, where it once got up to 222F. After I started moving again, it came back down but kinda slowly.

I should also mention that I removed the pass. side fan to make room for my charge piping and put a small pusher fan (a SPAL fan from a motorcycle actually) on the front of the condenser.

Fast forward to last weekend when I went autocrossing. It was disgustingly hot out. 98F and sunny and a bit humid. After each run, the temp would be higher and higher, to the point that it was idling at 220F. This is with the A/C off mind you. In a panic I pulled the relay for the compressor and turned the a/c on, forcing the front mounted condensor fan to run. It's quite small, but it managed to bring the temps down to a more livable 208F. Ok so I just need more fan.... or so i thought.

After the event was over. I was soooo looking forward to driving home with the a/c blasting. So i attempted just that. However, I managed to get temps up to 230 freaking degrees... on the highway. I reluctantly turned the a/c off expecting temps to come right down, but they didn't. After another 15 minutes or so of highway driving (no more than 60mph. I didn't want to exacerbate the problem), it gradually came down to 215.

So apparently i need more fan for low speed and idle, but there's definitely something else amiss here. The car should never have gotten that hot on the highway.

I was considering getting a Mishimoto radiator and fans, but I'm already running an auto trans radiator. Why should I really need more than that? I'm also missing the belly pan and funky air scoop thing behind the bumper (wouldn't fit with the intercooler). Could those really make that much of a difference funneling air through the radiator? My intercooler does NOT block the whole entire opening. In fact I have it mounted quite low and as such it only really blocks half of the opening. I also put in a 180F thermostat hoping it would do the trick. It runs about 200F on the highway in mild temperatures.

It's obnoxious because I cant really drive the car anywhere because of this. I'm trying to sell my DD (to get another one) and I'd like to daily drive the Miata for a few weeks while I get that whole process sorted out. But I doubt it would survive my commute, which can get quite nasty with traffic at times.

So what should i do first? Adding dual fans is going to be a PITA as it would mean I have to re-do a good part of my charge piping but I think it's unavoidable at this point. I'd also rather not spend the money on an all aluminum oversized rad if i can avoid it.

The last option is to set my car on fire. But I'd rather save that as a last resort.


HELP!!!

well i would loose the fmic and go WI, short of that get your ducting back right. And then throw bigger fans on there and see if it helps.

Just a heads up, I idle/highway/stop and go around 199-207F in 90 degree + high humidity with A/C on with 75/25 water/coolant + water wetter and a koyo 37mm rad and very good ducting.

Its difficult to get this cars cooling issue under control without a coolant reroute imo.

How are fans going to help on the highway? Do the regular stuff first ... make sure you get all the air out of your cooling system. Make sure you have the right mix of coolant/water.

Get the undertray back on there too. If the car is healthy, you shouldn't be having these problems.

207 I could deal with just fine. 230 is just absurd. I'm not putting in WI (seriously is that necessary for a t25 running 8psi?), and I've heard that a coolant re-route doesn't actually help bring temps down. I mean are people running off the shelf Fm and BEGI kits experiencing the same thing here?

And I know the fans aren't going to help on the highway (actually maybe they will if I'm not getting any air to the rad), but they're certainly going to help at idle/stop and go. I think my problem is a lack of air to the radiator all around. I have to trim the belly pan to get it to fit back on with the intercooler piping in place. I just wonder if it really makes that much of a difference.

It will make a huge difference. The air will hit the rad and just go around. The belly pan will help force it into the radiator. Made 10-15 degree difference in my temps. Also try going to 85/15 water/coolant and add a bottle of water wetter. Cheapest way to get the temps down.

Do some research on coolant reroutes here, I've really yet to hear much bad, in fact I've heard "too cold" more than "doesn't work".

Run as much fan as you can. Make sure your radiator is sealed so the air goes through it instead of around it. Get a real radiator, big deal your running an automatic radiator who cares it holds about 2 ounces more water than a stock unit. Run as little antifreeze as you can and add some water wetter. These should be the basics, then you can start looking at a coolant reroute if needed but get the basic system up to par.

And for the record the fans help on the highway too. Unplug you fan and go for a highway drive and watch what happens.

Your asking for help and arguing with people giving you answers.

What thermostat you running?

check for hose leaks and your cap and if your thermostat isnt failed maybe flush with a 70:30 water to antifreeze mixture.

If there isn't a mechanical issue with leaks, air in the system or a bad cap. Absolutely try to seal around the radiator to keep air from getting around it. All the air entering the mouth of the car needs to be forced through the rad. This made a huge difference on my car at the track on hot days.

I'm running a 180F thermostat. I just changed it actually from the 195 I had installed hoping it would help somewhat. Even though it makes no sense for it to. :)

I think I know where to start. Thanks everyone.

You don't need a coolant reroute, bigger fans, a different radiator, or anything aftermarket at all - you have a basic cooling system problem you need to solve. Bad cap, stuck thermostat, failing water pump. Get the undertray back on it ASAP - that is crucial to the cooling of this car.