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Mountune Fiesta ST Radiator Upgrade

Sekred

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Mid North Coast
Buttonwillow Raceway Park 09/27/2017, ~75F ambient
Mountune radiator - Distilled water /w Nano Cool
Mishimoto Oil Cooler - Pennzoil Platinum Ultra
CPE intercooler
215/17 Dunlop ZII on 7.5" wheels
Brembo BBK
Meister ZCRD coilovers

Only running 2:09 - 2:10 laps due to not having coilovers aligned or corner balanced yet, and being *very low* on sleep [facepalm]. My PB at that track is 2:08 on stock tires and stock suspension.

Had Mountune install their radiator this week on my ST. With the stock radiator and the Mishimoto oil cooler, coolant would reach 250F after 4 hot laps in similar weather. With the Mountune radiator, coolant didn't go over 220F over a ~15 minute session. That's a big improvement, but I think I will still have to add hood vents to get peak coolant temps 5-10F lower and also make car trackable 4 seasons.

Well that's a realistic data log of IC performance.
 


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I'm planning on ordering one soon. I am still torn on which one to order. Please someone just make a decision for me!
 


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I have installed both. Mountune wins the ease of installation hands down. I ran with a friend (friend I installed the Mishi on and I have the Mountune) same time same track day and we were within a few degrees of each other..... That is basically an answer without me telling you what to do.

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jayrod1980

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Just get the mountune... efficient, near stock installation, less hassle. I love my mountune radiator... suffers none of the issues I had stock. I don’t even have my oil cooler installed yet and it gets the job done... and it’s a little lighter than the Mishimoto.
 


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Nurburgring
Another datalog from a ~95F track session in California. Coolant hits 240F, car significantly bogs down on straights :( . I won't be driving car again in hot weather (> 75F) until I get a hood vent solution.



[video=youtube;Ydpf4MJnR3g]https://www.youtube.com/watch?v=Ydpf4MJnR3g[/video]
 


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Location
Arlington, VA
Hmm, that's discouraging. I'm torn about whether it's worth it to plunk down the cash for a radiator if it's still not clear it's up to serious track duty in the summer.
 


M-Sport fan

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I think I'd benefit from a larger oil cooler core indeed :)
I had an idea of a full length across the bottom of front bumper cover in place of the factory 'air dam' thing.
But I was not sure IF it would receive enough of that 'high pressure air' everyone speaks of in order to cool effectively, besides being MUCH more prone to damage/destruction.

I do NOT like the idea of blocking even a tiny section of even an aftermarket radiator (let alone the factory one) on these over-heating prone cars with ANYTHING!!
(WHY I am really reluctant to do the VT Big Mouth, driving lights, oil cooler there, horns, etc. like everyone else does without a care. ;) )
 


KKaWing

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Is that the *calculated* oil temperature from the Cobb AP? Unless you know the variables involved, I'm not sure it can be trusted. The closest thing that to an oil temp. sensor I've seen from the Windows version of Forscan is a cylinder head temperature "trigger" probe.

I had an idea of a full length across the bottom of front bumper cover in place of the factory 'air dam' thing.
But I was not sure IF it would receive enough of that 'high pressure air' everyone speaks of in order to cool effectively, besides being MUCH more prone to damage/destruction.

I do NOT like the idea of blocking even a tiny section of even an aftermarket radiator (let alone the factory one) on these over-heating prone cars with ANYTHING!!
(WHY I am really reluctant to do the VT Big Mouth, driving lights, oil cooler there, horns, etc. like everyone else does without a care. ;) )
I wonder if the crash sensor bar can be cut down. Say leaving the top or bottom "flat" portion that is in-line with airflow and cut the rest out in a trapezoid shape would help. I remember someone doing speed holes and it didn't do much.
 


jayrod1980

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An issue with this setup is that the oil cooler pretty much blocks a good portion of the area the condenser and radiator depend on to get air. Mine will be mounted in front of the intercooler. It’s going to probably raise my charge air temps a bit, but the DHM IC is a monster. I also have my grill completely open, so there’s no closed off blank areas like stock. Hard to believe at any speed that coolant would get that high. I’ve flogged my car on some twisty roads (def not close to what you are doing) at 115 degrees and the coolant never got that high. I’m also up around 2000ft and lower humidity... not sure how that would affect it comparatively.
 


jayrod1980

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RAAM did cut his crash bar down a lot and stuck a Setrab or similar oil cooler over toward the passenger side of the car... it blocks much less of the air to the radiator.
 


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I think maybe the oil cooler will cool your oil, but it's looking like having that hot oil cooler in front of the intercooler is going to raise the coolant temps (and charge temps) somewhat. I'm not sold on an oil cooler yet. I have the dhm crash bar and race Intercooler with the Mountune.

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jayrod1980

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I think maybe the oil cooler will cool your oil, but it's looking like having that hot oil cooler in front of the intercooler is going to raise the coolant temps (and charge temps) somewhat. I'm not sold on an oil cooler yet. I have the dhm crash bar and race Intercooler with the Mountune.

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Me too, but I doubt it will by much. Mines just the little 12x4x2 plate cooler and I’m mounting it below the crash bar. The DHM race still has plenty of capacity, and they won’t be touching. On any boost I’m less than 5 degrees above ambient... sometimes it exactly ambient briefly when releasing the throttle after a pull. I even got rid of the front license plate just to get every bit more air through the grill. Perhaps the cooler isn’t needed, but it’s definitely the weak link under load. That little liquid heat exchanger just doesn’t cool well when the engine is at a boil. I’ve been at 184F with the new radiator and 215F with oil... not even a high load, just 85 MPH cruise.

Edit: There’s no reason at all for coolant temps to rise... the placement of the oil cooler won’t be blocking the existing air flow for the radiator, unless you think the radiator gets much air at all with that 3 inch thick bar and plate intercooler covering the lower region of the front of the car? I think actually that the stock liquid heat exchanger benefits from the new radiator at low speeds/rpms because oil is moving slower over the exchanger. It just can’t do much when the oil pressure is high and it’s cycling fast when you are heavily on throttle. Or I could be wrong about how oil circulation works.
 


M-Sport fan

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I wonder if the crash sensor bar can be cut down. Say leaving the top or bottom "flat" portion that is in-line with airflow and cut the rest out in a trapezoid shape would help. I remember someone doing speed holes and it didn't do much.
Are you referring to the whole actual factory crash BAR, or just the sensor & mount??

I'd rather try to find a DHM crash bar than to start plasma cutting apart that crash beam.
It's safer than chopping up the factory beam, and by cutting the factory beam you are potentially opening yourself to even more possible insurance problems (in the event of a head-on collision and subsequent claim denial, total or otherwise) than just installing the DHM bar, YES, IF you can find one!

The increased air flow to the radiator (especially with a shaved grill), and slightly less mass, are the reasons I would want the DHM bar even with a factory fit IC. ;)
 


jayrod1980

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It definitely would be nice if someone were to buy up DHM’s plans and assets and continue making the crash bar and intercooler. Whatever anyone says about Russ... the race IC and bar craftsmanship are awesome. I don’t regret purchasing it one bit.
 


BronxBomber

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Another datalog from a ~95F track session in California. Coolant hits 240F, car significantly bogs down on straights :( . I won't be driving car again in hot weather (> 75F) until I get a hood vent solution.



[video=youtube;Ydpf4MJnR3g]https://www.youtube.com/watch?v=Ydpf4MJnR3g[/video]
Out of curiosity, are you on the stock turbo? Also what peak boost are you running? Fuel? Thanks
 


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Nurburgring
I was able to improve the efficiency of the Mountune radiator using high temp resistant EPDM foam strips around it to force air to go through it. By default there's lots of gaps around the rad. Also I realized that the stock fan shroud's "flaps" aren't able to open fully after the radiator install due to lack of clearance. So I removed all 5 flaps as well.

The result is equilibrium coolant temps (a first for me!) at 70F weather.



Oil temps still climb throughout the session however. Next step would be to install a larger/more efficient oil cooler core. For tracking in spring/summer, hood vents will still probably be needed.
 


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I was able to improve the efficiency of the Mountune radiator using high temp resistant EPDM foam strips around it to force air to go through it. By default there's lots of gaps around the rad. Also I realized that the stock fan shroud's "flaps" aren't able to open fully after the radiator install due to lack of clearance. So I removed all 5 flaps as well.

The result is equilibrium coolant temps (a first for me!) at 70F weather.



Oil temps still climb throughout the session however. Next step would be to install a larger/more efficient oil cooler core. For tracking in spring/summer, hood vents will still probably be needed.
Very interesting post! I'm going to have a look at those flaps when I get a chance. With the DHM race bar/intercooler I know that I have even more significant gaps around the sides that aren't easily filled with foam I doubt.

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