Track Time Limited due to High CHT

[NeverSatisfied]

I never seen the oil temps even into yellow though. ECT's were up to 224F according to track addict logging. But the CHT's was high at 242 cht. I didn't feel pulled timing and improved my times a lot this time out. But I still think that better cooling is obviously needed.

Reduced power may be unique to ‘21 my?

It doesn’t happen right away. It happens when I linger at 235+ for about 10 minutes into the session, and calc oil temp gets to yellow. Back out for all of 30 seconds, drop ect to 234, the oil temp drops out of yellow and I’m back to full power. However if I jump right back in it I’m back to reduced power.

No idea how ford calculates oil temp? I’d just be guessing cht, average load%, and time by the results I’m seeing.

Either way agreed on your comments, my target is sub 225 cht when caning.

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[bnightstar]

Reduced power may be unique to ‘21 my?

It doesn’t happen right away. It happens when I linger at 235+ for about 10 minutes into the session, and calc oil temp gets to yellow. Back out for all of 30 seconds, drop ect to 234, the oil temp drops out of yellow and I’m back to full power. However if I jump right back in it I’m back to reduced power.

No idea how ford calculates oil temp? I’d just be guessing cht, average load%, and time by the results I’m seeing.

Either way agreed on your comments, my target is sub 225 cht when caning.

It's not unique to the 21 my car is doing it as well. Just wasn't doing it this time but I limited my sessions to just 2 fast laps. Just so I don't fight with the engine and ruining rest of my day. By the looks of it the calc for ECT is based on time at RPM range and CHT temps. So it's going up when you are on straights and going down on the corners. With that in mind I think is better to look into CHT temps only.

 

[67Fast_V]

It's not unique to the 21 my car is doing it as well. Just wasn't doing it this time but I limited my sessions to just 2 fast laps. Just so I don't fight with the engine and ruining rest of my day. By the looks of it the calc for ECT is based on time at RPM range and CHT temps. So it's going up when you are on straights and going down on the corners. With that in mind I think is better to look into CHT temps only.

It seems everyone has a different perspective on what is an acceptable CHT (in regards to your question on whether 242F is okay). In a previous post, I outlined what I thought was an acceptable/reasonable level and that is 235F CHT and 275F oil and 225F A10 trans (Flyhalf's experience). So if you are interest in the logic, you can go back and take a look. But everyone has an opinion and I'm not saying mine is any kind of "absolute". Ford knows what the engine can take and they have put markers/controls in place.

As Never mentioned, the rpm constraints/limits are a good indication of what Ford thinks is acceptable. Keep oil less than 280F and ECT less than 244F (my stock tune file). Now do they mean CHT less than 244F, I'm not sure.

Now all of us would like 210-220F CHT max, but you have to make more serious mods to get there and is that worth it? Or I could just slow down ... but who likes that. So it's an individual decision. For me. I happy to get below the Ford thresholds w/ some margin. That last 15-20 hp w/ reduced temps is not going to make or break my lap times. Driver mod is way more important. Now the time trail and wheel-to-wheel drivers have different goals and I can totally respect that. Cheers.

 

[GTP]

Here is a top down photo of the condenser, trans exchanger, and radiator. I measured the trans cooler height at 4" and the radiator height at 16". Could a second OEM cooler (or even a third) be added below the first and then cascade them with hoses? Just an idea...

 

[tosha]

There's a lot of smart people in this thread, so let me ask this - aside from the steep cost, any thoughts on this Roush kit https://www.roushperformance.com/2018-2021-roush-supercharged-max-cooling-upgrade.html and maybe even repurposing one of the radiators from supercharger cooling into engine oil cooler? The % numbers they provide don't seem to be huge, but then it's whole new air flow, avoid stacking rads in front of each other, and aligned with mach 1 extra cooling solution. Thoughts?

 

[GTP]

There's a lot of smart people in this thread, so let me ask this - aside from the steep cost, any thoughts on this Roush kit https://www.roushperformance.com/2018-2021-roush-supercharged-max-cooling-upgrade.html and maybe even repurposing one of the radiators from supercharger cooling into engine oil cooler? The % numbers they provide don't seem to be huge, but then it's whole new air flow, avoid stacking rads in front of each other, and aligned with mach 1 extra cooling solution. Thoughts?

Hey, that was my idea! I think I posted it above, or perhaps in another thread.

Anyway, I went to the trouble to email and call them. They kept advising against it, but I think it was because of the rework required to repurpose the supercharger cooler to be the trans cooler.

Yes it is expensive, but I really like the look of the new grille. Combined with a diff cooler, I *would be* out about $3k. Still cheaper than trading for a Mach 1.

*Edited to clarify I have not I implemented this idea.

 

[tosha]

Hey, that was my idea! I think I posted it above, or perhaps in another thread.

Anyway, I went to the trouble to email and call them. They kept advising against it, but I think it was because of the rework required to repurpose the supercharger cooler to be the trans cooler.

Yes it is expensive, but I really like the look of the new grille. Combined with a diff cooler, I'm out about $3k. Still cheaper than trading for a Mach 1.

Sure, not claiming copyright on it
So, have you actually done this or is it in planning phase? I really like the look of it as well, and I don't care too much about IAT2 to dedicate one more entire cooler for it. If you have done this, would be very interesting to know how it helped.

 

[GTP]

No, I am still in the research phase. As I've said, I prefer a turnkey solution. Apparently that is available for the diff, and perhaps for the oil, but it is the trans that is my #1 concern. Seems like mmr, Mishi, Steeda, or someone would be interested in this.

I like the looks of my car as is, so I'm not keen on cutting the bumper for small coolers. But I don't really trust the notion that stacking up coolers in front of each other is an efficient scheme either.

I have a (unposted) comment to add about cutting the fan shroud as posted earlier. I also wonder if there is depth available to add another couple of fans at the very front for a push-pull idea.

 

[GTP]

Also I should say I've talked to a good Ford service manager about all this. I have the VIN of a Mach1 with A10, and asked him if we could find the part #s for all the coolers and brackets etc. He thought it seemed doable.

 

[tosha]

Also I should say I've talked to a good Ford service manager about all this. I have the VIN of a Mach1 with A10, and asked him if we could find the part #s for all the coolers and brackets etc. He thought it seemed doable.

let me try to make it a bit easier for you : TRANS OIL COOLER.. 2022 Ford Mustang Mach 1 Coupe 5.0L V8 A/T | Lakeland Ford Online Parts, Lakeland FL

Not sure if that is the one you're looking for, as it seems to fit a lot of other trims, but take a look.

Seems that you can also search by VIN there: Mustang Mach 1 Coupe Parts - Buy OEM Mustang Parts Online - Lakeland Ford

 

[tosha]

you might look into digging into different configurations and parts on this site as well, for example this seems to be a set for GT500 transmission: Trans Oil Cooler for 2020 Ford Mustang | OEM Ford Parts

 

[67Fast_V]

There's a lot of smart people in this thread, so let me ask this - aside from the steep cost, any thoughts on this Roush kit https://www.roushperformance.com/2018-2021-roush-supercharged-max-cooling-upgrade.html and maybe even repurposing one of the radiators from supercharger cooling into engine oil cooler? The % numbers they provide don't seem to be huge, but then it's whole new air flow, avoid stacking rads in front of each other, and aligned with mach 1 extra cooling solution. Thoughts?

With the extra surface area and airflow from this kit, most certainly this will help reduce temps. And once the OEM system capability is exhausted, then going in this direction makes sense especially for a boosted set-up.

On repurposing HX's from this kit, there are a lot of other options that are much cheaper. Plenty of oil/trans cooling individual HX's on the market.

As far as putting another trans cooler below the OEM unit, yes, plenty of room. Might be better from a simplicity and weight standpoint to just remove the OEM and install a larger one. But could certainly plumb 2 in series if desired. However, CHT will take a small hit w/ the larger trans cooler in the OEM position.

If I need more oil or trans cooling, I will look to lay the HX flat in front of the condenser/radiator and allow the air to exit inside the underbelly tray and out the back of the tray under the car. This way the heat released from the oil/trans cooler does not impact the radiator heat rejection capability (not increase CHT).

 

[67Fast_V]

Just wanted to provide an update based on my track event on 6/16. Prior to the event, I completely sealed off the radiator (95-98% anyway), so that all the airflow coming through the grille will go through the radiator (and of course the engine inlet). So very minimal leaks. No other changes where made.

Result: Progress made. Huge difference in cooling, better than I expected. Max CHT was 246F but the ambient temp was 100.4F (engine inlet temp=105.8). I was expecting 238-239F max CHT but that prediction didn't include a change in amb temp. See data below.

March 2022
Tamb/Tinlet/max CHT/mods
82.4F/87.8F/247F/fan shroud mod, hood louver, ~50% radiator sealing

June 2022
100.4F/105.8/246F/fan shroud mod, hood louver, ~95-98% radiator sealing

Although the max CHT is not much difference, the actual difference in cooling is huge when corrected for ambient conditions. When I correct the June data to the same ambient as March, I get CHT=232 max and then factoring in a slight difference in driving intensity and duration, I would have expected 235F on a 82.4F day. So that is a 12 deg F CHT reduction from 50% sealing to 100% sealing.

I know it's painful and tedious to seal this system off, but the benefits are clear. Note that when I talk about sealing I don't mean boxing the radiator in. I mean physically sealing the system between the grille and the radiator, everywhere, so there are minimal leaks.

In summary, I think you can draw 2 conclusions from this data.
(1) this confirms the root cause of the OEM cooling issue and that is, it's a lack of airflow through the radiator.
(2) the system still does not have enough airflow for a hard charging A10 for 20 min HPDE session in the FL heat.

Next step: Install my modified grille which will reduce CHT by at least 10F and put me in the 235F range (target) on a super hot day. And in the FL winter when it's 70F, should be below 210F.

 

[GTP]

Sorry, I don't mean to be a jerk, but I'm not convinced by any of this.

Air flow is dependent on pressure delta between inlet and outlet sides, and restriction (i.e. the fins). Boxing in the radiator may increase inlet pressure, but I think the outlet side pressure is still the enemy if it remains unchanged (and which is probably ambient pressure of ~1 bar).

IMO adding a sufficiently large hood vent will decrease outlet side pressure more than boxing will increase inlet side pressure. If it is located "correctly" (wherever that is precisely) and the large engine cover is removed then it also would be directed over the cylinder head.

I think a better way to increase inlet pressure would be to add double fans ahead of the 3 coolers for a push-pull arrangement. I don't recall seeing this suggestion on the forum (though I certainly haven't read every cooling thread).

A it stands, air exits mostly out the belly pan, and that may help the transmission a little.

Furthermore, we are relying on the OEM dual fans and road speed for air flow. You can still have high RPMs even at lower speeds because of shifting. But the proposed extra set of fans are always running regardless of road speed. Just an idea.

 

[67Fast_V]

Sorry, I don't mean to be a jerk, but I'm not convinced by any of this.

Air flow is dependent on pressure delta between inlet and outlet sides, and restriction (i.e. the fins). Boxing in the radiator may increase inlet pressure, but I think the outlet side pressure is still the enemy if it remains unchanged (and which is probably ambient pressure of ~1 bar).

IMO adding a sufficiently large hood vent will decrease outlet side pressure more than boxing will increase inlet side pressure. If it is located "correctly" (wherever that is precisely) and the large engine cover is removed then it also would be directed over the cylinder head.

I think a better way to increase inlet pressure would be to add double fans ahead of the 3 coolers for a push-pull arrangement. I don't recall seeing this suggestion on the forum (though I certainly haven't read every cooling thread).

A it stands, air exits mostly out the belly pan, and that may help the transmission a little.

Furthermore, we are relying on the OEM dual fans and road speed for air flow. You can still have high RPMs even at lower speeds because of shifting. But the proposed extra set of fans are always running regardless of road speed. Just an idea.

Hi GTP - I can understand some unbelief, as the cause and solution offered may not be inline with general or typical cooling thoughts/causes/solutions. But remember this is road course track data, and not bench calculations, street driving, auto cross, etc. It's the real deal.

As mentioned previously, this data comes from the OBD2 port hard wired into my laptop located in the car. I have HPtuners VCM scanner software that records ~50 parameters every 0.25 secs during the entire track session. And after each session, I review the data. And more extensively at home.

If you trust that I'm not going to fabricate the data or results, then the next question is ... what caused the improvement in cooling? How can max CHT be the same with 18F hotter ambient temp. I certainly didn't slow down much. And not mentioned previously, but later in the day when ambient dropped to a nice and cold 95F, max CHT was 241F. Correlates perfectly to the lower ambient temp and a solid improvement from March. ... So why and how come??

To better understand the physics and why the improvement, would suggest rereading post #183 and #185. That should help on the physics and fan situation. And let me know if you have any other questions. Glad to help where I can. And good luck w/ your car. Cheers.

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