Track Time Limited due to High CHT

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
Hi Folks - kind of new here and wanted to ask a question. I'm having an engine cooling issue and wanted to know if this is common for Gen 3 S550 GTs. I have done some digging but it's not clear to me and hence my direct question.

I have mostly a track car ... '20 GT PP1 A10 but stock at the moment and I can't run more than 3-4 laps (maybe 6-9 mins) before I hit 250F CHT. I'm really surprise that this is occurring. I replaced the t-stat w/ a 170F because the OEM was defective. Around town, CHT is 182-198F range. So perfect/no issue. But when I open this up at the track, the engine gets hot very quickly. The trans temp is good for now ~ 221F max and the rear diff is okay for now as well ~252F max (note this is after wrapping the exhaust and changing to 75W-140 ... which made a huge difference).

Have others had this same problem at the track ... or is it likely unique to my car? Would appreciate your thoughts/experience. Thanks.

 

Ewheels

Well-Known Member
Joined
Apr 5, 2019
Threads
55
Messages
1,119
Reaction score
1,207
Location
SoCal
First Name
Eric
Vehicle(s)
2018 GT PP1
Vehicle Showcase
1
Hi Folks - kind of new here and wanted to ask a question. I'm having an engine cooling issue and wanted to know if this is common for Gen 3 S550 GTs. I have done some digging but it's not clear to me and hence my direct question.

I have mostly a track car ... '20 GT PP1 A10 but stock at the moment and I can't run more than 3-4 laps (maybe 6-9 mins) before I hit 250F CHT. I'm really surprise that this is occurring. I replaced the t-stat w/ a 170F because the OEM was defective. Around town, CHT is 182-198F range. So perfect/no issue. But when I open this up at the track, the engine gets hot very quickly. The trans temp is good for now ~ 221F max and the rear diff is okay for now as well ~252F max (note this is after wrapping the exhaust and changing to 75W-140 ... which made a huge difference).

Have others had this same problem at the track ... or is it likely unique to my car? Would appreciate your thoughts/experience. Thanks.
Unfortunately, these cars do have a cooling problem. Personally, I would have backed off before CHT hit 240 let alone 250. That's dangerous.

Most S550 track guys run hood vents and seal the radiator on the front side so the incoming air can only go through the radiator.
I saw improvement instantly from RaceLouvers hood vent. I will eventually seal the radiator as well but I'm more into Time Attack so a couple laps is all I need.

You could also try a triple pass radiator to bring temps down further
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
Unfortunately, these cars do have a cooling problem. Personally, I would have backed off before CHT hit 240 let alone 250. That's dangerous.

Most S550 track guys run hood vents and seal the radiator on the front side so the incoming air can only go through the radiator.
I saw improvement instantly from RaceLouvers hood vent. I will eventually seal the radiator as well but I'm more into Time Attack so a couple laps is all I need.

You could also try a triple pass radiator to bring temps down further
Bummer ... but thanks for the head-up. Appreciate the input. I agree with you on 240F is a better slowing down point. I wasn't happy about the 250F but it just happens so quickly. This was my 2nd track event w/ the car. For example, just going down a straight away from say 55 - 130 mph, the temp rises 9F. So you go in at 232 and come out at 241F. And then is cools a few degrees in the turn and then I have another straight that comes right after and that is worth 6 degs. So ~ 13 degs in straight-turn-straight. Maybe 0.8 mile.

What is troubling is the PP1 radiator is a good size. That's why this is surprising to me. Put it this way, the PP1 radiator has the same capacity as my previous car (C7 Z06 ... okay try not to give me a hard time about this, long story). 460 hp vs. 700 hp, same capacity. Ran 225-230F ECT in the Z06 (after 25 min session) which equates to roughly 240F CHT.

But what you are indicating is that this is a dP problem across the radiator. Downstream pressure is too high (back pressured) and reduces the airflow through the core.

The radiator is not sealed well on the sides but the top looks okay. I need to check the bottom. I can certainly put some blocking material on the sides and address the bottom if needed. Will do that before the next event. Thanks.

Good idea on the vents. How much benefit in CHT or run time did you get from them? Painful to cut the hood.

Is it worth much to removed the hood sealing strips on the sides and the rear (at least the side regions)?

Any wheel well or fan/fan shroud or other mods worth investigating? Thanks again for your help.
 

NightmareMoon

Well-Known Member
Joined
Nov 22, 2015
Threads
36
Messages
4,258
Reaction score
2,824
Location
Austin
Vehicle(s)
2016 Mustang GT PP
Vehicle Showcase
1
What condition is your radiator in? I know mine's getting pretty dinged up and it finally got into the red zone at a track day for the first time. 6-9 minutes ain't much and might indicate a cooling system problem.
 

smokescreens

Well-Known Member
Joined
Jan 1, 2021
Threads
35
Messages
269
Reaction score
146
Location
michigan
First Name
jason
Vehicle(s)
2014 impala, 2017 HD. 2018 Royal C mustang gt pp1
The pp's use the slightly larger gt350 radiator. But i think im going to go with a mishimoto radiator with its huge increase in cooling over factory. A cooler thermostat is good and all but if the stock radiator cant keep the temps down it wont matter if you have no thermostat at that point.
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
The pp's use the slightly larger gt350 radiator. But i think im going to go with a mishimoto radiator with its huge increase in cooling over factory. A cooler thermostat is good and all but if the stock radiator cant keep the temps down it wont matter if you have no thermostat at that point.
My PP1 radiator is new, has 1500 miles on it. Condenser is clean, very minimal bugs. I am amazed at how fast this engine heats-up. Now granted I'm not loafing and I do have the A10 which I paddle shift near redline until CHT climbs enough and the computer says no which is on the 3rd lap. And then it cool down time and major short shifting. But still, 6-7 mins and I'm done. Pretty bad.

The Mish radiator appears to have a lot more capacity but ewheels indicates this may be more of an airflow issue and not a radiator size. So I feel like I need to investigate and test a bit more before the radiator purchase.
 

ZPD

Well-Known Member
Joined
Jul 10, 2018
Threads
16
Messages
168
Reaction score
77
Location
TX
Vehicle(s)
2017 GT Premium
For what it's worth I upgraded from my PP radiator to a 3 row SVE radiator (basically the same as the Mishimoto but slightly deeper) and I didn't see much improvement on how many laps I could get before I got to the danger zone. I have a set of Tracspec louvers ready to go into the hood. A Harrop Oil cooler will likely be next to allow my oil to be air colled rather than using the engine coolant. I am doing all the changes one at a time so I can gauge what has the greatest effect.
 

Plimmer

Well-Known Member
Joined
May 10, 2015
Threads
8
Messages
659
Reaction score
362
Location
San Antonio, TX
First Name
Rob
Vehicle(s)
2015 Mustang GT
The radiator is not sealed well on the sides but the top looks okay. I need to check the bottom. I can certainly put some blocking material on the sides and address the bottom if needed. Will do that before the next event. Thanks.
Sounds like some kind of cooling system issue. Sealing the radiator in is a good improvement, but you’re heating up so fast that something else could be wrong, but hard to pinpoint what.

You’ll have to just go through everything and check all is good.
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
For what it's worth I upgraded from my PP radiator to a 3 row SVE radiator (basically the same as the Mishimoto but slightly deeper) and I didn't see much improvement on how many laps I could get before I got to the danger zone. I have a set of Tracspec louvers ready to go into the hood. A Harrop Oil cooler will likely be next to allow my oil to be air colled rather than using the engine coolant. I am doing all the changes one at a time so I can gauge what has the greatest effect.
Thanks for the feedback ZPD. That's good info ... and if it is an airflow issue, then adding more radiator won't solve it. I think you have a data point that proves this. Now granted I assume you have a heat exchanger in the front for your whipple. Correct? If so, then that adds more difficulty in cooling and could better understand the challenge. I'm pure stock which makes me scratch my head.

Good approach to do things 1 at a time, in my opinion. I try to do the same thing when possible.
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
Sounds like some kind of cooling system issue. Sealing the radiator in is a good improvement, but you’re heating up so fast that something else could be wrong, but hard to pinpoint what.

You’ll have to just go through everything and check all is good.
Thanks. I will pull the new t-stat and see if if has the bypass stuck wide open like on the defective OEM. That would explain it. I have maybe 300 miles on it. Hard to believe its bad but certainly possible.
 

luc

Well-Known Member
Joined
Mar 25, 2018
Threads
13
Messages
1,068
Reaction score
1,013
Location
CA
Vehicle(s)
2017 GT with PP
Thanks. I will pull the new t-stat and see if if has the bypass stuck wide open like on the defective OEM. That would explain it. I have maybe 300 miles on it. Hard to believe its bad but certainly possible.
It’s not normal
Did you check your coolant temperature and oil temperature when your Cht was so high?
Keep in mind that the car has an oil-to-water cooler and that add a huge thermal load to the cooling system
Getting ride of this system and adding an air-to-cooler will pay huge dividends
I track a 17 pp1 with 305 squared nt01 and with my Harrop oil cooler, on a 105* day, maximum oil temp was below 260 and water 230
I get the water temp through the obd2 port and oil with electrical gauge with the sensor on the line out of the block
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
It’s not normal
Did you check your coolant temperature and oil temperature when your Cht was so high?
Keep in mind that the car has an oil-to-water cooler and that add a huge thermal load to the cooling system
Getting ride of this system and adding an air-to-cooler will pay huge dividends
I track a 17 pp1 with 305 squared nt01 and with my Harrop oil cooler, on a 105* day, maximum oil temp was below 260 and water 230
I get the water temp through the obd2 port and oil with electrical gauge with the sensor on the line out of the block
Yes, I checked ECT and oil the best I can during elevated CHT. The ECT indicated runs about 9-12 cooler than CHT. So if CHT is 250F, ECT is 240F ish. On oil temp, I just have the idiot gage in the displayed instrument panel. It's hard to look at while on the track but I did toggle to it when I noticed it said high and it was at the edge of the red zone. But I slowed down to look at it and with point bys and such, it didn't take long to drop down into the yellow.

I logged the data through the OBDII port using HPtuners software. So I have all available pids in real time while on the track. ECT is available but unfortunately oil is not. My understanding is that oil temp is a calculation but even the output of that calculations is not available through HPtuners software. My understanding is that even ECT is a calculation. Is that correct?

I would like to measure oil and coolant directly but haven't researched how to do it. I am very interested in how you are getting oil temp and where you are tapping into the system.

And yes, I agree the oil heat load is taxing the cooling system. Those are great temps from your set-up. I might have to go in that direction but for now, I'm just trying to understand how could the temps be this bad in pure stock condition. Thanks for your input, Luc 👍.
 

Flyhalf

Well-Known Member
Joined
Feb 25, 2018
Threads
24
Messages
1,084
Reaction score
1,145
Location
CA
Website
www.youtube.com
First Name
Alessandro
Vehicle(s)
Mustang GT 18 10speed auto PP1 , GT500 '21
Hello.
I have a 2018 pp1 10sp.
Heating is main issue for our cars.
Some advice
1. Remove coolant water mix and change with 10%coolant 90% and add water wetter
2. Cht are also connected to engine oil temps. Is weird u have cht issue before oil issue. If trackcar consider to go with better and heavier oil. I use 0w40 mobil but if in the heat, u can do 5w50(according to ford perf)
An oil cooler is highly recommended. Less oil temp less CHT temp too.
WHAT TEMPS U SEE FOR OIL. ?( green yellow or red?)
3. Vents. Ravelouvers vent are proven to be great for cooling and DOWNFORCE TOO.
4. I have mishimoto radiator. Bigger than oem. Works nice
Btw i feel there is somenthing going on if you had to change the thermostat already. Wonder if there is some issues that overheat the CH
5. MOST IMPORTANT. DUCTING. YOU NEED TO DUCT THE RADIATOR.
6. If track car remove the AC CONDENCER
7. Trans temp: never EVER EXCEED 225F. If u do u may loose the trans.
8. shift before. In a racing no one with a street car can sustain redlight shifting. You have a 10 speed so 4 and 5 are pretty close. So use always 5. Drop 7th on the straight.
Shift 6500rpm.

Note. Remember to NOT INSTALL AN OIL COOLER IN THE UPPER GRILLE cause you will cover the trans cooler otherwise.

Little trick for the diff.
Poor some water in front a leaf blower and blow (and spray) the diff for 1-2 min. Temps will drop a lot.
Hope this help.
Alessandro

IMG_20210922_120025_914.jpg
 
OP
OP

67Fast_V

Well-Known Member
Joined
Sep 1, 2021
Threads
5
Messages
74
Reaction score
32
Location
FL
Vehicle(s)
2020 Mustang GT PP1 A10, 1967 Fastback 460ci+
Hello.
I have a 2018 pp1 10sp.
Heating is main issue for our cars.
Some advice
1. Remove coolant water mix and change with 10%coolant 90% and add water wetter
2. Cht are also connected to engine oil temps. Is weird u have cht issue before oil issue. If trackcar consider to go with better and heavier oil. I use 0w40 mobil but if in the heat, u can do 5w50(according to ford perf)
An oil cooler is highly recommended. Less oil temp less CHT temp too.
WHAT TEMPS U SEE FOR OIL. ?( green yellow or red?)
3. Vents. Ravelouvers vent are proven to be great for cooling and DOWNFORCE TOO.
4. I have mishimoto radiator. Bigger than oem. Works nice
Btw i feel there is somenthing going on if you had to change the thermostat already. Wonder if there is some issues that overheat the CH
5. MOST IMPORTANT. DUCTING. YOU NEED TO DUCT THE RADIATOR.
6. If track car remove the AC CONDENCER
7. Trans temp: never EVER EXCEED 225F. If u do u may loose the trans.
8. shift before. In a racing no one with a street car can sustain redlight shifting. You have a 10 speed so 4 and 5 are pretty close. So use always 5. Drop 7th on the straight.
Shift 6500rpm.

Note. Remember to NOT INSTALL AN OIL COOLER IN THE UPPER GRILLE cause you will cover the trans cooler otherwise.

Little trick for the diff.
Poor some water in front a leaf blower and blow (and spray) the diff for 1-2 min. Temps will drop a lot.
Hope this help.
Alessandro

IMG_20210922_120025_914.jpg
Hi FH - many thanks for the input. Much appreciated👍. There is a lot to chew on here. It seems I'm not alone with these high temp problems. Good in a sense to know that vs. unique issues with my car. Let me answer a few of your questions to put my experience in context.

Oil temp is hard to look at while on the track but I have seen it in the yellow and slightly red zone w/ high CHT (250F). So very sporty oil temps as well.

See attached photo of the 180F OEM t-stat (new, 1000 miles on it). I found this condition after my 1st track event. Bypass wide open + main circuit stuck open a tad. I had about 4-5 mins on the track before reaching high CHT. Replaced with 170F. Now I get 7-9 mins of track time☹.

Current coolant/water mix is 33% assuming OEM was 50/50. I can certainly drop that living in FL.

I bought the A10 because I love the gearing. It has a big advantage over the MT84D manual as you well know. I calculate a 9% increase in ave torque over a 40-146 mph speed range. That's using 2nd through 7th. Running 3rd through 7th, its about 4.5% advantage.

Okay, let's forget calculations. My last event, I had a '20 PP2 GT in front of me on the back straight of Sebring. He exited T16 with a good gap in front (maybe 5-6 cars length). I closed the gap and had to lift off the throttle to avoid getting to close to him. And then I found out that he had a modified exhaust system and high flow air filter. Pure stock for me (with 240-250 CHT). Just a data pt for the A10. No surprise to you I'm sure. I use 3rd through 7th and shift at 7000 rpm.

My goal is to continue that but it sure would be nice to get more than 7 mins of run time. I did try 4th - 7th and shifting at 5500 rpm. Still gets ugly, just takes longer. Maybe 12-15 mins. It would totally stink if I have to do this to keep CHT behaved.

Was running 5W-30 Mobil 1. I wanted to go 5w-50 but scared. Oil pressure really jumps up with rpm w/ the 5w-30. Just worried that oil wedge will not be right with Gen 3. Do you know track guys running 5w-50 in fresh Gen 3 motors?

Seems hood vents are the way to go. Thanks. Hard for me in FL, though. Rains every 10 mins. But I will likely need to go in that direction. Still drive car on the street and to and front the track. AC in south FL is important. Too hot otherwise.

I'm going to work on ducting the radiator before my next event (early Nov) and remove all the hood seals. Can't do your kind of good job but I will try to block the flow the best I can.

My trans temps were surprising good. Only hit 221F max. So this is encouraging but I was hindered by CHT so I should expect higher levels soon. Will keep your limit of 225F as the gage. Thanks 👍.

Oil cooler is an option. That might have to be the next major step. Hole in the hood or air-to-air oil cooler. Tough decision.

My diff temp on 1st event hit 294F. The usual ugliness. Exhaust wrap + 75W-140 reduced 42F. Max is 252F now. Different track but very similar ave speed and track time. Happy enough with that for now, but I like the blower and water idea. Thanks.

Not ready for a bigger radiator just yet. Seems my main issue is airflow through the radiator, hence the hood vents, ducting etc. Will attack that first.

I wonder if anyone has done or tried any fan shroud rework??? I'm thinking about going in this direction as well before my next event.

Thanks again for the input. I will let you know how things go. Cheers.
IMG_4631.JPG
 

Ewheels

Well-Known Member
Joined
Apr 5, 2019
Threads
55
Messages
1,119
Reaction score
1,207
Location
SoCal
First Name
Eric
Vehicle(s)
2018 GT PP1
Vehicle Showcase
1
@67Fast_V I've seen you mention it twice now....DO NOT remove the hood sealers on the rear of the hood next to the windshield. That's a localized high pressure area and if removed, you'll just force more air back into the engine bay rather than evacuating it.

1634313467465.png


1634313593101.png
 

 
16 - CJ Pony Parts - 2
Top