Mountune Fiesta ST Radiator Upgrade

[KraZe]

Mainly with 30% or higher concentrations of Dex Cool chemistry coolants.

In 100% water, it is fine.

If you are worried, dump that mixture, flush the system (yeah, I know it's a pain with the bleeding and all ) and install a 25/75, or 30/70 mixture, and use one of the other brand additives if you feel the need.

Took your advice and did just that 25/75 in it now. Thanks for warning me would have sucked to learn that the hard way.

 

[M-Sport fan]

After now seeing the factory fan/shroud assembly out on it's own, I wonder just how effective a DUAL, MUCH MORE powerful in cfm (each) fan, shroud would be for those always having problems with overheating in torrid climates while sitting in stop and go traffic, even with the factory radiator?

NOT that ANY manufacturer would ever make one up for us, and yes, I know many on here swear up and down that the factory fan's quality and longevity CANNOT EVER BE matched by ANY aftermarket fan manufacturer, no matter their rep for quality/performance, nor co$t.

 

[jayrod1980]

When removing the stock radiator, don't be an idiot like me... wear some goggles or safety glasses. Pulling the cooling pack sandwich apart netted me bug and thorn confetti all over my face on multiple occasions during this install. Having goat heads go through your gloves into your hands from the foam on the stocker is always fun too. Amazing how much crap gets stuck in there in 2 years time.

 

[jayrod1980]

Still no 100 degree days to test the radiator but it's WAY better than stock! Adam definitely changes when the fan comes on because the coolant temp never gets above 194F. Once the fan kicks in, coolant stays between 181-188F in 97F weather.

Check out my Accessport on my 30 mile ride home from work. This is about 20 mins in, going about 80MPH on the highway. Hoping to get a better indication of the improvement as it might get up to 105F today.

Sent from my iPhone using Tapatalk

 

[KentRatke]

This Rad is so, so much better than stock. Overheating used to occur once a week in the heat but it has never done it since.

 

[KraZe]

This radiator is keeping my coolant temps at 190F like clockwork. Whether in 75F or 95F ambient always 190F. Doesn't go lower than 189F and hottest it got to was 194F while idling for 15 min.

And for those that are curious, this radiator is only 1.5 lbs heavier than stock.

 

[jayrod1980]

Mine briefly goes up to 192-194F when starting the car, but haven't seen higher than 190F afterward and it idles at 183F, even in 100F. It's awesome!

 

[KraZe]

I HAVE SOME GREAT NEWS:

I was a bit skeptical of this radiator considering it's size is not much larger than stock and the fact that my coolant temps around town were never in the 180Fs like Mishimoto users claim.

BUT

I just came back from my track day and have nothing but good things to say about it. Only 1.5 lbs heavier than stock and with only an extra half quart coolant this radiator kept my temps at 228F and below in 95F ambient heat in two separate 10 min sessions (7 laps) with 5 of those laps being taken flat out in a row. When I had the stock radiator I could only manage 2 consecutive fast laps before overheating (250F coolant temps and full H on the temp sensor + limp mode). I'm pretty sure this radiator could have kept me cool even if I had done over 15 fast laps without stopping.

VERY IMPRESSED. HIGHLY RECOMMEND. QUALITY AND PERFORMANCE IN ONE.

 

[jayrod1980]

That's really great man! Personally, I've not hit 200F on this guy even roasting in 107F traffic along with the DHM cooler that blocks a lot of the access to free air. It's definitely a night and day difference. I'd like to talk to people that actually have a working stock radiator though to compare the improvement, because like some have said, not everyone has a faulty radiator.

 

[KraZe]

That's really great man! Personally, I've not hit 200F on this guy even roasting in 107F traffic along with the DHM cooler that blocks a lot of the access to free air. It's definitely a night and day difference. I'd like to talk to people that actually have a working stock radiator though to compare the improvement, because like some have said, not everyone has a faulty radiator.

Well I never considered my radiator faulty it worked perfectly for daily driving just utter crap for track use.

 

[HardBoiledEgg]

I have a 2017 and plan on this once I get some track time in the car stock


I don't care if people say my car won't have a problem, and car on the track should think about this


Also deleting the water to water oil cooler. And put a real cooler

 

[ThaiFiesta]

Also deleting the water to water oil cooler. And put a real cooler

I'd be interested in knowing more about this.

 

[M-Sport fan]

I'd be interested in knowing more about this.

Mishimoto already has a kit for these cars, but I wish that others would join them (like; Setrab, Mocal, etc.).

 

[sidewaysallday]

I have a 2017 and plan on this once I get some track time in the car stock


I don't care if people say my car won't have a problem, and car on the track should think about this


Also deleting the water to water oil cooler. And put a real cooler

I have the Mishi rad/oil cooler specifically because I track my car and can tell you that running it full tilt (solo group with PCA) at Watkins Glen for 20 minute sessions and the rad/oil cooler didn't even seem phased (in 85 degree heat). Well worth it IMO.

 

[HardBoiledEgg]

Deleting the water cooler on the oil I think is a must. Let's the coolant cool the motors water and let's the oilncooler coolnthe oil. There is a good thread about it on this forum!

 

[KraZe]

Oil cooler definitely helps but I've seen people on this forum report they overheated even with the Mishi oil cooler but NO ONE has overheated with an upgraded radiator, Mishi or not.

 

[M-Sport fan]

The irony is that the factory oil to coolant system does HELP those in very cold climes during the winter season in heating up the oil quicker to get it flowing at the proper rate, and to ALL critical areas of the engine.

Of course this is a NEGATIVE for those in torrid climates, unless they are ONLY doing very short trips, in which case it might help heat up the oil enough to burn off the moisture, and fuel dilution which comes with cold running and short trip use.

 

[KKaWing]

The irony is that the factory oil to coolant system does HELP those in very cold climes during the winter season in heating up the oil quicker to get it flowing at the proper rate, and to ALL critical areas of the engine.

Of course this is a NEGATIVE for those in torrid climates, unless they are ONLY doing very short trips, in which case it might help heat up the oil enough to burn off the moisture, and fuel dilution which comes with cold running and short trip use.

Yep, I love the oil heater... my Versa constantly made mocha frap. in the winter. Not something you want to see regularly.

 

[HardBoiledEgg]

For me in SoCal it's constantly hot and hotter. Any opinions on it?

 

[Chops]

I'm in the same boat here in AZ, hot as hell with temps reaching almost 120 this summer, my coolant temps are over 240 on my daily 30 mile commute. I have been comparing these two radiators (Mishi vs. Mountune) for a while now and could use all of your input. Looks to me like the build quality of the Mountune is a little higher and its obviously lighter but it seems that the Mishi does cool a little better. I plan to go with the one that does an overall better job of cooling along with the Mishi thermostat.

Please share your opinions and experiences with these two radiators as well as where to purchase them for the best price with the quickest shipping.

thanks in advance!