Track Time Limited due to High CHT

[Xgamex22]

Pushing slightly harder will definitely have a big difference in how hot the engine gets, as does RPM. If I go 9/10 my CHTs would blowup to 250+, going 6/10 I can keep them in the mid-high 230s all day, and if I'm putting around at 3/10 they stay in the 220s. All on the same day.

Couple things about your and your buddie's situation. An autox event is generally slow(er) speeds than most regular tracks. You are not going to get the same airflow in and out so I'm not really surprised that a vented hood didn't make much of a difference. Also your buddy only hitting 90 (which is 194 F) means he wasn't going at it at ALL! That sort of CHT is for people that just cruise lightly, any meaningful acceleration and your temps will instantly climb over 200. So the fact that he wasn't getting out of the 190s means he wasn't doing anything anywhere near what you were doing.

While i do agree with all said i still think the temp jumping so quick its not even funny i took the car for a drive to simulate the track (somewhat) by s mode and keeping it on third gear once the car reached 98c cht i released the gear and let the car cruise for while it jumped to 105 before start going down and touch the reservoir and the radiator both side of radiator were hot with minimal difference between the two side

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[honeybadger]

While i do agree with all said i still think the temp jumping so quick its not even funny i took the car for a drive to simulate the track (somewhat) by s mode and keeping it on third gear once the car reached 98c cht i released the gear and let the car cruise for while it jumped to 105 before start going down and touch the reservoir and the radiator both side of radiator were hot with minimal difference between the two side

I think a lot of people underestimate how much impact engine load has on CHTs. A wide open run under heavy load will spike CHTs 30 degrees in less than 20 seconds. Not abnormal to me.

Sustained higher CHTs are more of a concern

 

[Bossdog]

I don’t know, the OP’s situation doesn’t seem normal. Auto cross is a one minute run at best half of which is a full throttle ( broken up into 3, 4 or five events) and then you wait 20 minutes or 30 minutes for the next run. It just doesn’t seem like this should be an issue. Even before I put my oil cooler in. I never had issues at auto Cross

 

[Xgamex22]

I don’t know, the OP’s situation doesn’t seem normal. Auto cross is a one minute run at best half of which is a full throttle ( broken up into 3, 4 or five events) and then you wait 20 minutes or 30 minutes for the next run. It just doesn’t seem like this should be an issue. Even before I put my oil cooler in. I never had issues at auto Cross

Exactly my point its get hot so fast even before any upgrade was better now even worse than stock so one of two things either the radiator is not efficient or the oil to air cooler not the best solution

 

[ihasnostang]

i sent it on an e85 tune around road america, ~55 degrees. oil, coolant, ETC. No warnings though. pretty much got 1 fast lap for every 2-3 cooldown ones. graph not made from that session in video

 

[Hack]

I finally got a good test of my cooling modifications. 2017 GT PP1. Track louvers are the only engine cooling modification. I have not done anything to block air from bypassing the radiator. At Road America over July 4th and I had no problems at all. I have the Ford Performance power pack 3 with the GT350 intake, throttle body and tune, so I was running the car up beyond the factory redline. Ambient temperatures were in the mid to upper 80s during this event. I had no temperature issues at all and the car performed flawlessly.

 

[MrMike]

I finally got a good test of my cooling modifications. 2017 GT PP1. Track louvers are the only engine cooling modification. I have not done anything to block air from bypassing the radiator. At Road America over July 4th and I had no problems at all. I have the Ford Performance power pack 3 with the GT350 intake, throttle body and tune, so I was running the car up beyond the factory redline. Ambient temperatures were in the mid to upper 80s during this event. I had no temperature issues at all and the car performed flawlessly.

Really seems like the biggest issue with the 15-17 hood design is simply no way for the heat to escape.

Center vent seems to be most important to just let the hot air from the radiator escape. Pretty obvious why the S650 has a vent there at this point.

I'm not fast enough for that to matter much yet, and I'm still 50/50 on cutting my hood vs aftermarket hood.

 

[Hack]

Really seems like the biggest issue with the 15-17 hood design is simply no way for the heat to escape.

Center vent seems to be most important to just let the hot air from the radiator escape. Pretty obvious why the S650 has a vent there at this point.

I'm not fast enough for that to matter much yet, and I'm still 50/50 on cutting my hood vs aftermarket hood.

After running at RA, I decided I'm a terrible novice driver. My time off during COVID did me no favors at all. I missed probably 99% of the turn ins. But I don't think that matters for car temperature very much at a track like RA. The straights are so long you get close to the car's maximum speed a couple times per lap. There is plenty of continuous foot to the floor driving at triple digit speeds.

I think that the Track Louvers design helps to pull air through the radiator. Just having a hole in the hood might not give you the same benefit. I would ask around before you pick an aftermarket hood.

 

[MrMike]

After running at RA, I decided I'm a terrible novice driver. My time off during COVID did me no favors at all. I missed probably 99% of the turn ins. But I don't think that matters for car temperature very much at a track like RA. The straights are so long you get close to the car's maximum speed a couple times per lap. There is plenty of continuous foot to the floor driving at triple digit speeds.

I think that the Track Louvers design helps to pull air through the radiator. Just having a hole in the hood might not give you the same benefit. I would ask around before you pick an aftermarket hood.

That sounds like a faster track than either of the ones at NJMP. While TBolt is the faster one, there is still only one main straight where I can even get close to max speed. There's some other points where I'm ~100 but not 130+ like the main straight.

Agree. The aftermarket hood design I am considering is a GT500 hood. It's a known quantity at this point.

 

[Hack]

That sounds like a faster track than either of the ones at NJMP. While TBolt is the faster one, there is still only one main straight where I can even get close to max speed. There's some other points where I'm ~100 but not 130+ like the main straight.

Agree. The aftermarket hood design I am considering is a GT500 hood. It's a known quantity at this point.

I'm not sure. NJMP sounds plenty fast from your description.

One other thing to mention about the track louvers + swing with Gurney flap setup I'm running. Getting more air through the radiator will increase drag and decrease your top speed. I wanted the downforce along with cooling for safety.

I didn't find that many cars were running up on me, though. The GT350s in my group seemed similar in top end/acceleration. A ZL1 and Supra in my group were the only two cars that had a lot more acceleration and top end than my GT.

 

[MrMike]

I'm not sure. NJMP sounds plenty fast from your description.

One other thing to mention about the track louvers + swing with Gurney flap setup I'm running. Getting more air through the radiator will increase drag and decrease your top speed. I wanted the downforce along with cooling for safety.

I didn't find that many cars were running up on me, though. The GT350s in my group seemed similar in top end/acceleration. A ZL1 and Supra in my group were the only two cars that had a lot more acceleration and top end than my GT.

ZL1 is quite fast IME. I've had an odd assortment of cars in Novice so far this year. There's usually some Corvettes and stuff along the lines of a GT500 or ZL1, but the event before last someone brought a Huracan. Unsurprisingly, it was fast.

I like the FP spoiler/swing but I am afraid to drill my trunk. We'll see how I feel next year. I usually do my mods in the spring.

Yep, GT350 vs GT w/PP3 is a difference of 31hp. I'd wager they're more likely to be better on turns due to magneride.

 

[GTP]

I finally got a good test of my cooling modifications. 2017 GT PP1. Track louvers are the only engine cooling modification. I have not done anything to block air from bypassing the radiator. At Road America over July 4th and I had no problems at all. I have the Ford Performance power pack 3 with the GT350 intake, throttle body and tune, so I was running the car up beyond the factory redline. Ambient temperatures were in the mid to upper 80s during this event. I had no temperature issues at all and the car performed flawlessly.

Oh man, I wish I knew you were going, as well as any other 6g members. I went Friday and Saturday. I pitted in the grassy area near the entrance to the grid. I saw a black GT there near the fence, if that was you. I ran in Group 2.

I thought I had cooling problems licked, but my CHT climbed to 250-260 on the long straights. I had to start short shifting on the straights, and I even used 8th gear for the first time! That is what kept me out of limp mode. I learned the track pretty well, and I did a 2:40 as my best lap. What a fun track!

 

[Hack]

Oh man, I wish I knew you were going, as well as any other 6g members. I went Friday and Saturday. I pitted in the grassy area near the entrance to the grid. I saw a black GT there near the fence, if that was you. I ran in Group 2.

I thought I had cooling problems licked, but my CHT climbed to 250-260 on the long straights. I had to start short shifting on the straights, and I even used 8th gear for the first time! That is what kept me out of limp mode. I learned the track pretty well, and I did a 2:40 as my best lap. What a fun track!

Ahh, that stinks! I've had so many past cooling issues I can really relate. Good that you found a solution.

It should have occurred to me to post something here asking who was going. For some reason I didn't even realize @honeybadger was there.

Yes, I was parked near grid entry, kind of in the middle of the grass rather than near the fence. I was the under-equipped person with just a cooler and small tool box. Later in the day I spent most of my time in the shade watching turns 5 and 1, though. I got really hot sitting in the sun. The car held up to the heat a lot better than I did!

 

[tosha]

I'm still 50/50 on cutting my hood vs aftermarket hood

Usually, takeoff stock hoods from Marketplace is the cheapest and most effective option, especially in common colors like black/grey/white.

 

[MrMike]

Usually, takeoff stock hoods from Marketplace is the cheapest and most effective option, especially in common colors like black/grey/white.

I'm pretty sure my color is the first or second most rare lol. Unless the hood in your pic is carbon fiber, something tells me you can relate.

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