Overheating issue during Autocross

[Andres3165]

It is known of some , not all FiSt overheat at Autox, has anybody a clue why, ? Somewhere I read complete coolant flush might help, if so let Ford do it?

Mine is a 2017

Thanks

Andres

 

[Erick_V]

The stock radiator is insufficient for extended periods of hard driving. I'm fully bolted and e30 and I never overheated at autox yet another fiesta owner at the same event, nearly stock went into limp mode at autocross. Some are lucky like myself others aren't so much. I would recommend the Mountune Radiator, I believe it's still on sale for $475 at the moment and you'll likely never overheat at autocross again

 

[m3kerry]

Overheated this weekend pop the hood turn the heat up to max and spray the intercooler pipes

 

[HardBoiledEgg]

SPRAY INTERCOOLER IS DOING NOTHING LOL

SPRAY THE RAD

 

[Andres3165]

The stock radiator is insufficient for extended periods of hard driving. I'm fully bolted and e30 and I never overheated at autox yet another fiesta owner at the same event, nearly stock went into limp mode at autocross. Some are lucky like myself others aren't so much. I would recommend the Mountune Radiator, I believe it's still on sale for $475 at the moment and you'll likely never overheat at autocross again

I compete in HS so cannot change it.

Andres

 

[Andres3165]

Overheated this weekend pop the hood turn the heat up to max and spray the intercooler pipes

Did the same this weekend lol.

Andres

 

[Erick_V]

I compete in HS so cannot change it.

Andres

Ah I see. I'm in Street Mod so I can pretty much do anything lol. I got tired of HS pretty quick. Weird to me how an aftermarket radiator that would mount in the OEM location would be against the rules considering its heavier and wouldn't necessarily help your performance. After runs I just pop the hood, blast heat and it usually bleeds off enough heat for my next run.

Edit: I don't remember what temp thermostat comes with what years of the cars but you could look into the 180 degree thermostat. Would give you a little more headroom before overheating.

 

[The_Ryan]

My coolant gets hot (up to 230, usually no more than 220 tho) with my stock radiator with the heat running with heat on max. Another two FiSTs that show up (bone stock) have overheated

 

[M-Sport fan]

I don't remember what temp thermostat comes with what years of the cars but you could look into the 180 degree thermostat. Would give you a little more headroom before overheating.

Do the draconian, nonsensical, SCCA H/Street rules even allow for THIS?!?

 

[Erick_V]

Surprisingly, yes lol

 

[theblue]

run the heat on max during the autoX run may help a little. the heater core is really just another radiator. Running E30 will also help with cooling a hair and you'll get more power also.

 

[the duke]

Do the draconian, nonsensical, SCCA H/Street rules even allow for THIS?!?

Update/Backdate rule.

I was under the impression a replacement radiator was allowed provided it was not smaller, had the same mounting/fit in stock location, and held at minimum the same amount of fluid for this very reason. Maybe I'm thinking outside of stock class only.

 

[scooter123]

I wonder if the H Street rules allow a slight modification to the windshield washer system. Basically move the sprayers to a location in front of the radiator. Need a bit of extra cooling then spray the radiator with a high methanol content washer fluid.

 

[jeffreylyon]

run the heat on max during the autoX run may help a little. the heater core is really just another radiator. Running E30 will also help with cooling a hair and you'll get more power also.

Running E30 will reduce power w/o a tune and he can't modify the base tune in H/S.

Run straight water with water-wetter; coolant reduces water's ability to conduct heat. Remember to go back to 50/50 before the winter hits.

The FiST doesn't have a whole bunch of water or oil to sink heat into but I'd be surprised if you go from a warm-ish engine to limp-home-mode in a single run running straight water.

 

[foodtruck]

Can confirm, my car is stock and the temperature meter is usually at its upper limit after a quick 50s run. Once tried lapping it two times back to back during fun runs and it went into limp mode.

 

[AZSP33D]

It's not a thermostat issue, they are fully open above 208 degrees which is a sweet spot for making good power, opening sooner means you're heat soaking all of your coolant sooner also. HS doesn't allow improved radiators.

Factors are not holding full pressure (cracks in the lines or seals, or filler cap, schrader, etc), air in the system, not enough cool down between runs, and heat soak. The last two means as soon as you pull back on grid, prop the hood open, and you can spray down the engine with a mist of water from a sprayer if you want. Coolant can be changed, so you can use 75% distilled water instead of 50% as water has more heat dissipating capacity than glycol, and water wetter helps. Also make sure your coolant is serviced cap is tight and system holds pressure, and your always above the MIN line. Another thing to look at, is to make sure your fins are in good shape, not using AC that day until after the event, and baffling is properly in place. Oil also should be fully serviced with high quality stuff as one of the functions is cooling... also thicker than specified oil is less effective at cooling BTW. Lastly you can run the heater full blast directed out the windows if you're hitting over 230.

These engines seem to be prone to steam pockets in my opinion, and I think have a weak cooling system in general which certainly is a liability. One way to address these is drain all fluids, and service with 100% coolant (no water) and get it circulating well through the heater core, etc. then drain all of it, drain the reservoir, and service with EVANS waterless coolant, bleeding the system thoroughly at the schrader.. EVANS doesn't boil or create any pressure (until well above $350 degrees) so it is excellent for protecting the engine with a fragile cooling system. If there's any water left, you can very carefully remove the cap when it's up to temp and above boiling 212 degrees (without pressure that's where it boils) and any water will steam off. EVANS is expensive so a poor man's version is pure food grade Propylene Glycol (they add these to brownies and cookies to keep them moist) as it's about 1/2 the cost of EVANS. Problem with EVANS is that has less heat capacity then water, so the engine will run 3-4 degrees hotter under the same conditions, but it's very safe in an overheated condition if you often get there anyway. Some engines you can remove the reservoir alltogether as there is no pressure in the system once the water is removed (Fiesta is not one as coolant circulates through the turbo and into the res). Most ultra-high performance engines are designed to run at very high coolant temps, and most NA stuff makes the most HP on my dyno when it's at the verge of over heating (230-235 range, if it's on EVANS I let it get higher if the ECU is programmed to allow it)... The Ducati 1098R with aftermarket ECU and no radiator fan is fine at 240+ and runs great... BUT forced induction engines can benefit from running cooler temps as every time you're on the power, heat soak will be a reduction, and lower operating temps will give you more heat soak margin. My M5 V10 is mildly supercharged (only about 7 psi) so it benefits from a cooler 180 thermostat where as NA it certainly makes more power above 210... Evans coolant for the engine, and Engine Ice (whith is similar but with water added) for the heat exchanger. I believe Jay Leno has EVANS in all of his cars, as water/coolant is a little bit corrosive otherwise, and some older cars are very susceptible to cooling system issues. Anyway, point is it's not a fix all for the Fiesta especially with an enhanced turbo, but I have it in both cars and they are very well behaved with regards to cooling.

 

[PunkST]

My car has never gotten limp mode hot. Even when autocrossing in 100 degree heat 🤷. That being said after the crash fix it takes forever to get to 195. ( even on hot days like today it will take me a good 20 minutes of driving to hit normal temps)


When the car was bone stock. After every run id wet the tires/intercooler/radiator area with a weed sprayer full of water. Helped keep the car consistent.

 

[M-Sport fan]

Running E30 will reduce power w/o a tune

There were some on here (myself included, when I still had an E85 station local to me) who were running an E20-E25 mixture on a pure factory turbo/tune setup, and claiming a tiny bit more power, especially in summer heat.

One (I believe it was @ re-rx7) actually put up some dyno graphs showing surprising gains, yup, even without a tune.

But of course there is more power/optimization to be had with a proper, data log info adjusted tune.

 

[theblue]

yeah. you don't want to go too far. but we have O2 sensors and MAF that will adjust to some degree and shouldn't make less power until they really hate what they see. and you're not going to run hotter on E30 than you would on 93 given all else the same so it should pay off.

 

[Andres3165]

Problem officially fixed, after running back to back at the SCCA prosolo no issues. Changed the Thermostat to a lower temp 180 and change the coolant percentage to 25 %. done and big headache in the past

Andres