Track Time Limited due to High CHT

[bnightstar]

back at the track yesterday with 82 deg ambiant temp and had CHT of 234 with coolant and oil temps on real gauges at 220 ECT and 229 EOT.

I was at the track yesterday as well 86 deg ambiant temp and had a max CHT of 231 temp. That I noticed. but when sitting at the pits waiting for my session the car was getting wormer as it stand up to 219 CHT. Very worring.

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[tosha]

I was at the track yesterday as well 86 deg ambiant temp and had a max CHT of 231 temp. That I noticed. but when sitting at the pits waiting for my session the car was getting wormer as it stand up to 219 CHT. Very worring.

219F is roughly when the fans fully kick in. before then, there is no airflow. When I need to idle in pits or skidpad or whatever, I turn on the AC, it starts one of the fans and my CHT stays at 205F stable.

 

[bnightstar]

219F is roughly when the fans fully kick in. before then, there is no airflow. When I need to idle in pits or skidpad or whatever, I turn on the AC, it starts one of the fans and my CHT stays at 205F stable.

yeah i was without the AC so that makes sense you say nothing to worry then ? Here is the video from my best lap yesterday looks like the car is lacking power though:

 

[tosha]

yeah i was without the AC so that makes sense you say nothing to worry then ? Here is the video from my best lap yesterday looks like the car is lacking power though:

With AC turned off on a hot day, my CHT would climb to 219F when just standing in a traffic jam or stop and go traffic. It makes me uncomfortable as well, but then if you think about it, at this point the coolant temp is probably around 206F (97C), which is well below the boiling point. It just seems that this is how Ford engineers intended it for the street use.

AC helps me to start the sessions cooler, but to be honest, I don't think it matters too much because as soon as you go, the temps start living their own life. The better fix here would be a lower temp thermostat and a tune to kick in fans sooner. My Roush calibration allows me to turn on all fans at full speed whenever I want by holding the Set+ button and pressing brake for 5 seconds, that is good enough for me and it brings down CHT even faster than AC.

Can't say much about your power loss feel and whether there is something to worry about, you might have experienced a heat soak and it pulled timing, or maybe something else. Try playng with AC setting and see what happens with temps at idle, you can experiment with this on a parking lot, no need to be on track )))

 

[tosha]

Here is the video from my best lap yesterday looks like the car is lacking power though:

Watched the video, it seems that your speedometer has a noticeable delay, which is understood if you use phone GPS. It lags behind throttle input quite badly in some parts of video. You might look into buying a more precise gps and use that together with trackAddict app, or get a proper lap timer device (would be more expensive).
Otherwise, I cannot from a video whether car is lacking power or not.

 

[bnightstar]

With AC turned off on a hot day, my CHT would climb to 219F when just standing in a traffic jam or stop and go traffic. It makes me uncomfortable as well, but then if you think about it, at this point the coolant temp is probably around 206F (97C), which is well below the boiling point. It just seems that this is how Ford engineers intended it for the street use.

AC helps me to start the sessions cooler, but to be honest, I don't think it matters too much because as soon as you go, the temps start living their own life. The better fix here would be a lower temp thermostat and a tune to kick in fans sooner. My Roush calibration allows me to turn on all fans at full speed whenever I want by holding the Set+ button and pressing brake for 5 seconds, that is good enough for me and it brings down CHT even faster than AC.

Can't say much about your power loss feel and whether there is something to worry about, you might have experienced a heat soak and it pulled timing, or maybe something else. Try playng with AC setting and see what happens with temps at idle, you can experiment with this on a parking lot, no need to be on track )))

I have no issues on the street with AC except that my CHT on the highway is 208F(98C). But around town is down to 203F(95C). Regarding the gps lag you are correct on my Racebox terminal speed is 180 km/h not 173 km/h so big difference. I'm overall happy with how the car performs.

 

[Gnatsum21]

I was at the track yesterday as well 86 deg ambiant temp and had a max CHT of 231 temp. That I noticed. but when sitting at the pits waiting for my session the car was getting wormer as it stand up to 219 CHT. Very worring.

Have you tried this? Its supposed to turn on the fan, I haven't tried yet:

"Foot on the brake, hold the + cruise control button for about 10 seconds will turn on the fans. They stay running about 5 minutes after shutting the car off."

 

[bnightstar]

Have you tried this? Its supposed to turn on the fan, I haven't tried yet:

"Foot on the brake, hold the + cruise control button for about 10 seconds will turn on the fans. They stay running about 5 minutes after shutting the car off."

I didn't try that but will give it a shot. Maybe it will help.

 

[tosha]

Have you tried this? Its supposed to turn on the fan, I haven't tried yet:

"Foot on the brake, hold the + cruise control button for about 10 seconds will turn on the fans. They stay running about 5 minutes after shutting the car off."

It's specific to roush superchargers with roush tune. It works very well, I use it quite often.

 

[ZPD]

I had a track day today with Chin Track Days at Eagle Canyon Raceway. It was my first event there and it is a phenomenal track. Anyway, so far my cooling mods consist of a 3-row radiator (SVE I think), Harrop style air-to-oil cooler, boxing in of the radiator (probably better than 95%), Race Louvers center kit (just added), Trac Spec side louvers, opened up the stock grill, and probably 80/20 DI water to coolant with 2 bottles of water wetter. It was ~78 degrees in the morning, and by the 2 pm session, it was nearly 100 degrees. I still got CHT up to 255-260 after a few hot laps. I resigned myself to doing 2 hot laps and then 1 cool down in the morning sessions and then in the afternoon it was 1:1. This is so frustrating for me. TBH, I wish that I didn't do the supercharger. The power is incredible but it drives me crazy driving not being able to get the most out of it. I am convinced that the extra heat on the engine from the supercharger and the airflow going through the IC heat exchanger is stealing too much air from the radiator and it just can't be overcome. ARRRGH

Anyway has anyone used VP's Stay Frosty? One of the employees of the racetrack said that he used it for a his car that kept overheating and he dropped 20 degrees.

 

[tosha]

I had a track day today with Chin Track Days at Eagle Canyon Raceway. It was my first event there and it is a phenomenal track. Anyway, so far my cooling mods consist of a 3-row radiator (SVE I think), Harrop style air-to-oil cooler, boxing in of the radiator (probably better than 95%), Race Louvers center kit (just added), Trac Spec side louvers, opened up the stock grill, and probably 80/20 DI water to coolant with 2 bottles of water wetter. It was ~78 degrees in the morning, and by the 2 pm session, it was nearly 100 degrees. I still got CHT up to 255-260 after a few hot laps. I resigned myself to doing 2 hot laps and then 1 cool down in the morning sessions and then in the afternoon it was 1:1. This is so frustrating for me. TBH, I wish that I didn't do the supercharger. The power is incredible but it drives me crazy driving not being able to get the most out of it. I am convinced that the extra heat on the engine from the supercharger and the airflow going through the IC heat exchanger is stealing too much air from the radiator and it just can't be overcome. ARRRGH

Anyway has anyone used VP's Stay Frosty? One of the employees of the racetrack said that he used it for a his car that kept overheating and he dropped 20 degrees.

TBH, I would stay at home rather than go on track in a supercharged mustang at 100F ambient. It's probably easier to just buy a GT500

Which supercharger do you have? Have you considered moving to larger pulley to reduce boost? I think you're cooking the engine by doing what you have described.

 

[ZPD]

TBH, I would stay at home rather than go on track in a supercharged mustang at 100F ambient. It's probably easier to just buy a GT500

Which supercharger do you have? Have you considered moving to larger pulley to reduce boost? I think you're cooking the engine by doing what you have described.

you know what they about hindsight....

I have a whipple Gen 5

 

[tosha]

you know what they about hindsight....

I have a whipple Gen 5

I'm in the same boat - supercharged it "because it's great for street and I would never take this car to track", took it to a track just to try once... oh well, look where we are now...

I developed few strategies to go around it:
- ambient 70F and under - go go go
- 70F-77F - it works fine, just do some cooldown laps and have fun
- 77F-85F - pretend I have stock coyote with 460HP. Don't worry about lap times too much.
- 85F-90F - work on the line, braking, smooth steering, momentum driving. Hot laps are pointless.
- 95F and over - chill under canopy. Search for a cheap miata on marketplace.

 

[bnightstar]

I'm in the same boat - supercharged it "because it's great for street and I would never take this car to track", took it to a track just to try once... oh well, look where we are now...

I developed few strategies to go around it:
- ambient 70F and under - go go go
- 70F-77F - it works fine, just do some cooldown laps and have fun
- 77F-85F - pretend I have stock coyote with 460HP. Don't worry about lap times too much.
- 85F-90F - work on the line, braking, smooth steering, momentum driving. Hot laps are pointless.
- 95F and over - chill under canopy. Search for a cheap miata on marketplace.

You know what was mighty impressive to me last time out the cars in-front of me were all BMW M4/M2's all turbocharged engines. First session it was 75F and they were mighty fast. Second session the temps were 82F and the BMW's all of them lost 1.5 seconds off there best times in session 1. The Mustang was not slower at least was not slower before I overheat the brake pads. So Supercharged/Turbo charged engine is obviously more affected in increase in ambient temps than a N/A engine.

 

[tosha]

You know what was mighty impressive to me last time out the cars in-front of me were all BMW M4/M2's all turbocharged engines. First session it was 75F and they were mighty fast. Second session the temps were 82F and the BMW's all of them lost 1.5 seconds off there best times in session 1. The Mustang was not slower at least was not slower before I overheat the brake pads. So Supercharged/Turbo charged engine is obviously more affected in increase in ambient temps than a N/A engine.

Yeah, hot air is bad for boost and heatsoak is a bitch. Car has to fight with all sorts of issues when intake air gets too hot and too thin.

@ZPD , I found that running this thing in front of the car in between sessions for as long as possible helps start sessions with much cooler engine. It does not resolve any cooling limitations on track, but every little bit helps. It can also be used to cool down the diff pretty effectively.

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