Track Time Limited due to High CHT

[TundraOnKings]

Oil cooler is a must. Also remove heat from the little boiler of your OEM system.
Use water watter too dont forget.
Oil. I did nonissue 5w50 in summer (in california woth 110f) i do feel 0w40 is a better combo also to reduce drag. I also use MOTORKOTE as friction reducer \protection. Go 0w40. Pressure should be around 80psi or moe on WOT. it is normal.
Remember to cha ge fluid often. Including trans. Start to gst a friend in some dealership. (Bring donuts lol )
Last TRACKMUSTANGSONLINE.COM is a more track oriented forum.

Feel free to contact me on IG @italian_stang cauae is easier to chat. Or you can DM here.
I've been doing since 2 years now.
Ps. That pick was daytona so rain too but. If you dont really daily is ok.

Alessandro,
What are you using/prefer for track oriented oil? 0W-40, but what brand/blend? Any specific filter? Also, do you change engine oil after a few track days, say 6 x 20min sessions?
Also, what are you using for A10 trans fluid, and are you doing those services yourself? I haven’t researched A10 fluid change yet. I know some cars require machine/dealer.
I’m running the BG 75W-140 rear diff fluid and it seems excellent. Any certain number of track days you’re changing diff fluid as well?
Thank you!!!

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[67Fast_V]

Alessandro,
What are you using/prefer for track oriented oil? 0W-40, but what brand/blend? Any specific filter? Also, do you change engine oil after a few track days, say 6 x 20min sessions?
Also, what are you using for A10 trans fluid, and are you doing those services yourself? I haven’t researched A10 fluid change yet. I know some cars require machine/dealer.
I’m running the BG 75W-140 rear diff fluid and it seems excellent. Any certain number of track days you’re changing diff fluid as well?
Thank you!!!

TOK - not sure Alex is following this thread but he has commented in the past on several of your questions. Not sure on which oil he uses but many that track use 5w-50. I have change from 5w-30 to 5W-40. Mobil 1 synthetic. Maybe I will step it up to 5w-50 for the next round. I'm in FL, so the functional low is maybe 60F. I change my oil every 2 track days which is a pretty common approach. I use the stock Motorcraft filter FL-500S. Not sure what others do. I bet there is a big thread on oil and filters.

Alex uses stock ULV tranny fluid. He and Bob have tried other fluids and it didn't work well. Alex changes his tranny fluid every 4 - 6 track days. On the diff fluid change out, I change mine every 8-10 track days which is about once per yr. Not sure what Alex or others do. I also use 75w-140 diff fluid. Redline for me, the friction modifier version. That and exhaust wrap dropped diff temp 42F. Amazing improvement. No cooler needed for now. 3.55 rear gear in the A10 combo helps a tad on temps.

 

[TundraOnKings]

TOK - not sure Alex is following this thread but he has commented in the past on several of your questions. Not sure on which oil he uses but many that track use 5w-50. I have change from 5w-30 to 5W-40. Mobil 1 synthetic. Maybe I will step it up to 5w-50 for the next round. I'm in FL, so the functional low is maybe 60F. I change my oil every 2 track days which is a pretty common approach. I use the stock Motorcraft filter FL-500S. Not sure what others do. I bet there is a big thread on oil and filters.

Alex uses stock ULV tranny fluid. He and Bob have tried other fluids and it didn't work well. Alex changes his tranny fluid every 4 - 6 track days. On the diff fluid change out, I change mine every 8-10 track days which is about once per yr. Not sure what Alex or others do. I also use 75w-140 diff fluid. Redline for me, the friction modifier version. That and exhaust wrap dropped diff temp 42F. Amazing improvement. No cooler needed for now. 3.55 rear gear in the A10 combo helps a tad on temps.

Awesome! Perfect info, thank you kindly!

 

[67Fast_V]

Awesome! Perfect info, thank you kindly!

Glad to help

 

[bnightstar]

Awesome! Perfect info, thank you kindly!

I use OEM 5W20 Oil and filter change every 2-3 days following OLM recommendations or around 5000 km's and 2-3 days, Motul RBF660 brake fluid (this is causing me some pain at the moment as Is boiling often with the GLoc R10/R8 pads),
Motul DCTF Trans Fluid and Motul Gear Competition 75W140 for Differencial. I change Trans and Diff fluids ones every season or once ever 10 000 km's.

So Oil: 2-3 days.
Trans+Diff: Once a Season
Brake Pads: GLoc's are fine after 1 season, OEM I was going through them faster than OIL
Brake Fluid: Bleed after each day. Also if MT82 make sure to bleed clutch master as well.

I have 16 Track days spread over 2.5 seasons and 497 laps my track is 2 km long but 80 of this laps are on another track which is 3 km long so a total of 1074 track km's or (667 miles). Thinks that broke. 2nd season Rear left wheel hub bearings (3 times) , Trans fluid leak, Rear Swaybar Bushings, Stock generation broke at one outing last season but was cheap welding job. Now I obviously have some cooling problem that need addressing as I also have high ECT temperatures but I guess a new radiator and oil cooler is a must for this cars. I also have issues with my clutch pedal dropping to floor so I assume I'm in for an replacement clutch will probably go with Exedy 500 and lightweight flywheel.

 

[NeverSatisfied]

Once I got my temps in check with coolers I started running Kirkland 5/30 and changing. When the ecu said to (which was about 5-6 hr of track time) Makes for a cost efficient 10qt oil change

 

[67Fast_V]

For those that are following, wanted to give a quick update on my cooling woes.

Ran my local track on Sunday with 2 cooling mods. (1) Sealed the perimeter of the radiator and (2) modified the fan shroud to reduce as much restriction as possible. Pretest prediction was 235F Max CHT on a 85-90F day.

Before Mods: Tamb = 86F
Run time: 6-7 mins
250F+ CHT Note: CHT would reach a SS temp of 280F, as calculated
243F ECT
228F Trans
290+ Oil (red on the gage)
252F Diff (end of 20 min session)
Rise in CHT down straight-away: 10 degs F

After Mods: Tamb = 75F
Run Time = 17-18 mins
Max CHT = 241F (most of the time CHT was less than 236F, just a spike to 241).
Max ECT = 227F
Max Trans = 226F
Max Oil = roughly 280F (at the edge of the green-yellow)
Max Diff = 249F (no mods to the diff)
Rise in CHT down straight-away: 6 degs F

On an 86F day, I calc CHT to be 245F Max. So this is about 10F above my analytical prediction but 35F lower than the SS temp before the mods (280F).

So essentially, the sealing and fan shroud provided a 35F reduction in temp vs. expected 45F.
I guess not bad for a 1st cut analytical model.

But still have work to do to reach goal of 235F Max CHT ... but at least now I have a car I can actually run for a session.

Next Mod: Install vent/louvers in my spare hood. Calc that this is worth 5 deg CHT reduction but I'm guessing at the dump pressure at the louvers. Might be 7 degs but not likely more. So I'm still short of goal but close. Or maybe even close enough.

The oil temp is a problem. I don't like to run above 285F and I'm essentially there. No surprise. Pulling the oil cooling out of the engine coolant will get me to below my goal if the heat load stays out of the radiator circuit which is possible if I lay the HX horizontal in front of the condenser. So that is my plan. However I have a much larger tranny cooler to package as well. Haven't figured out the best way to package both. So a few things to sort out.

Side notes:
1) I beat my previous PR at this track by 1.1 secs. Not a surprise, given that temps are lower and I can start to get use to the car. This was only my 3rd track day with the car.
2) I was pushing hard and lost control of the car and went off track. Too much speed, trail braking, and just couldn't catch the back end. Just an ugly grass spin. Fortunately was able to avoid the walls.
3) Brakes were completely gone at the end. Only could run 3 of 4 sessions. Just stupid to run OEM pads. I know better.

@EG - never had a chance to test the 6500 vs. 7200 shift points. Too much traffic, bad lines around the track and always trying to push to make it up, and lack of concentration. I did notice that the ECU won't allow a 6th to 7th shift above roughly 6700 - 6800 rpm (fuel cut off). Not sure why but it's there for sure not cooling related. So that will always be a 6500 rpm shift for now.

Thanks for reading along. More when I further reduce the data. Cheers

PS: If you haven't sealed your radiator, I would highly suggest that you do . It's ~80% of improvement listed above.

 

[Flyhalf]

Alessandro,
What are you using/prefer for track oriented oil? 0W-40, but what brand/blend? Any specific filter? Also, do you change engine oil after a few track days, say 6 x 20min sessions?
Also, what are you using for A10 trans fluid, and are you doing those services yourself? I haven’t researched A10 fluid change yet. I know some cars require machine/dealer.
I’m running the BG 75W-140 rear diff fluid and it seems excellent. Any certain number of track days you’re changing diff fluid as well?
Thank you!!!

0w40 mobil1 euro formula.
Great compromise in price and quality (walmart 5 qaurts for 27$)
OEM FILTER.
I change oil every 3 days at the track. Max 1000miles anyway.

Trans fluid MUST BE OEM. I tried different weight. Didn't work.

For those that are following, wanted to give a quick update on my cooling woes.

Ran my local track on Sunday with 2 cooling mods. (1) Sealed the perimeter of the radiator and (2) modified the fan shroud to reduce as much restriction as possible. Pretest prediction was 235F Max CHT on a 85-90F day.

Before Mods: Tamb = 86F
Run time: 6-7 mins
250F+ CHT Note: CHT would reach a SS temp of 280F, as calculated
243F ECT
228F Trans
290+ Oil (red on the gage)
252F Diff (end of 20 min session)
Rise in CHT down straight-away: 10 degs F

After Mods: Tamb = 75F
Run Time = 17-18 mins
Max CHT = 241F (most of the time CHT was less than 236F, just a spike to 241).
Max ECT = 227F
Max Trans = 226F
Max Oil = roughly 280F (at the edge of the green-yellow)
Max Diff = 249F (no mods to the diff)
Rise in CHT down straight-away: 6 degs F

On an 86F day, I calc CHT to be 245F Max. So this is about 10F above my analytical prediction but 35F lower than the SS temp before the mods (280F).

So essentially, the sealing and fan shroud provided a 35F reduction in temp vs. expected 45F.
I guess not bad for a 1st cut analytical model.

But still have work to do to reach goal of 235F Max CHT ... but at least now I have a car I can actually run for a session.

Next Mod: Install vent/louvers in my spare hood. Calc that this is worth 5 deg CHT reduction but I'm guessing at the dump pressure at the louvers. Might be 7 degs but not likely more. So I'm still short of goal but close. Or maybe even close enough.

The oil temp is a problem. I don't like to run above 285F and I'm essentially there. No surprise. Pulling the oil cooling out of the engine coolant will get me to below my goal if the heat load stays out of the radiator circuit which is possible if I lay the HX horizontal in front of the condenser. So that is my plan. However I have a much larger tranny cooler to package as well. Haven't figured out the best way to package both. So a few things to sort out.

Side notes:
1) I beat my previous PR at this track by 1.1 secs. Not a surprise, given that temps are lower and I can start to get use to the car. This was only my 3rd track day with the car.
2) I was pushing hard and lost control of the car and went off track. Too much speed, trail braking, and just couldn't catch the back end. Just an ugly grass spin. Fortunately was able to avoid the walls.
3) Brakes were completely gone at the end. Only could run 3 of 4 sessions. Just stupid to run OEM pads. I know better.

@EG - never had a chance to test the 6500 vs. 7200 shift points. Too much traffic, bad lines around the track and always trying to push to make it up, and lack of concentration. I did notice that the ECU won't allow a 6th to 7th shift above roughly 6700 - 6800 rpm (fuel cut off). Not sure why but it's there for sure not cooling related. So that will always be a 6500 rpm shift for now.

Thanks for reading along. More when I further reduce the data. Cheers

PS: If you haven't sealed your radiator, I would highly suggest that you do . It's ~80% of improvement listed above.

I strongly strongly strongly suggest to never go 225f + with tranny.
Your 2 first priorities are
1. Bigger trans cooler
2. Oil engine cooler. This will help also CHT

Of course together with RACELOUVERS in the hood.
Attached how I did.

Fyi friday i take my car back with the latest MOD I've created to bypass the thermostat.

I'll report info

 

[67Fast_V]

0w40 mobil1 euro formula.
Great compromise in price and quality (walmart 5 qaurts for 27$)
OEM FILTER.
I change oil every 3 days at the track. Max 1000miles anyway.

Trans fluid MUST BE OEM. I tried different weight. Didn't work.

I strongly strongly strongly suggest to never go 225f + with tranny.
Your 2 first priorities are
1. Bigger trans cooler
2. Oil engine cooler. This will help also CHT

Of course together with RACELOUVERS in the hood.
Attached how I did.

Fyi friday i take my car back with the latest MOD I've created to bypass the thermostat.

I'll report info

Thanks for the input, Fly. 225F is pretty low, but I trust your judgment. I'm at that level now. I have seen mine at 201F just driving around town if a long enough trip.

That's quite the impressive set of coolers, spray, and louvers too . I'm going to start with the center vent and see what that does. Good luck with your tranny temp bypass. Hope it works out. It's certainly not ideal to start the cooling process at 190+. Cheers.

 

[EFI]

I strongly strongly strongly suggest to never go 225f + with tranny.

So based on this, would you say 210-212* is perfectly safe for durability?

I did my first 2 track days with the 10R and both times I was able to max it out around 208-210* (with only a short burst to 212*). Obviously I wasn't going balls out, nor was I shifting at redline, just wanted to get a feel for the car. But with the track configuration, I did not really need to wind it out to set respectable lap times, so I was happy with this pace.

Maybe on longer tracks I will get more heat in the trans, but the ones I run are not quite that.

 

[67Fast_V]

So based on this, would you say 210-212* is perfectly safe for durability?

I did my first 2 track days with the 10R and both times I was able to max it out around 208-210* (with only a short burst to 212*). Obviously I wasn't going balls out, nor was I shifting at redline, just wanted to get a feel for the car. But with the track configuration, I did not really need to wind it out to set respectable lap times, so I was happy with this pace.

Maybe on longer tracks I will get more heat in the trans, but the ones I run are not quite that.

Hard to believe you could do any damage at 212 deg F. I have run 200-205 driving around town in stop and go traffic. I have notice the A10 trans heats up more slowly and cools more slowly. Stock cooler isn't very big and there is a lot of fluid and thermal mass. So it makes sense. When you get more comfortable with the car and push and shift higher, temps will be going up. The tracks that have a lot of slow speed turns and you hold the lower gears (mainly 3rd) in them, temp will go up.

 

[Flyhalf]

So based on this, would you say 210-212* is perfectly safe for durability?

I did my first 2 track days with the 10R and both times I was able to max it out around 208-210* (with only a short burst to 212*). Obviously I wasn't going balls out, nor was I shifting at redline, just wanted to get a feel for the car. But with the track configuration, I did not really need to wind it out to set respectable lap times, so I was happy with this pace.

Maybe on longer tracks I will get more heat in the trans, but the ones I run are not quite that.

Yes.
In general. The cooler the better for an auto. Especially with a ULV fluid

 

[67Fast_V]

It's been a while since I provided an update on my cooling issues, so here it goes.

Since Nov 2021, I have run 2 additional track events. One w/ the same configuration as outlined above ("sealed" radiator + fan shroud mod) and one w/ added hood louver. Both still ran unacceptable temps. 251F CHT max w/o hood vent and 247F w/ vented hood. So the hood vent gave 4 degs lower temps. I was expecting 5 degs. So not a surprise that the vent didn't fix the issue.

But I believe I found the smoking gun. Based on my calculations, I decided the best course of action for my application/usage was to modify the grille to increase the flow. ISince the radiator flow is metered by the grille, I have to open it up by 50%+ to cool this beast off based on my calcs. It's an Aero hit but gotta reduce temps.

However when I pulled the front nose of the car to install the bigger grille, I noticed massive leaks around the radiator. I thought the system was mostly sealed but it wasn't. You can't see these leaks unless you remove the nose of the car. It's about 45 in^2 of open area which will bypass the radiator. Ridiculous. My calcs show that plugging this leak will drop CHT by 10F. So that will put me at 237F max which is pretty good, given the situation.

So I sealed the leaks and did not install the bigger grille. After I run in June, I will install the bigger grille which should put me around 229F max CHT (assuming the leak reduction gives me the expected benefit).

At this point, this is all on "paper" ... but I'm confident that I've found the solution for my usage. I should be able to get by with the stock PP1 radiator and stock oil cooler. The trans cooling will likely need some medicine. It's borderline to flyhalf's recommendation of 225F max. But after June's run in the FL heat, I will have better idea. Cheers.

 

[EFI]

I decided the best course of action for my application/usage was to modify the grille to increase the flow.

IMO that should have been one of the first things to do, especially if you vented the hood. I've seen massive gains from simply deleting the grille on both my S550s. It was even more pronounced (as expected) in my 2020 that has a big radiator behind it that was getting chocked. I was surprised to see how much of the area is blocked off in front, certainly done for MPG considerations.

I dropped between 12-15* CHT on track with simply opening up the top grill. 8-10* on the trans too since the cooler is at the top right inline the now open grill.

 

[Flyhalf]

I believe the leak might have created some air pockets. What is your daily temp?

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