Overheating at Track...Let me try this again!

[Learn2turn:)]

Removing the cowl and belly pan can potentially be harmful to cooling as it creates high pressure zones.

I understand that possibility but think it would be proven helpful to have more air exit potential in wind tunnel testing.

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[QuasarMotors]

I understand that possibility but think it would be proven helpful to have more air exit potential in wind tunnel testing.

Removing the belly pan is going to create lift at the front of the car (something you don't want on a FWD car). It is also going to negate cooling as now you have created turbulent high pressure zones under the car.

Removing the cowl is also a bad idea since that is a high pressure zone. Air while at speed will be trying to push into the engine bay making cooling even worse.

 

[Dave B]

Removing the belly pan is going to create lift at the front of the car (something you don't want on a FWD car). It is also going to negate cooling as now you have created turbulent high pressure zones under the car.

Removing the cowl is also a bad idea since that is a high pressure zone. Air while at speed will be trying to push into the engine bay making cooling even worse.

Agree completely.

Just thinking about this issue some more.

We seem to have 2 overheating issues, 1) with limp mode and engine temps causing the computer to pull some power and 2) with the computer pulling power due to higher IATs,. I know this sounds stupid coming from a guy who's knowledge of turbos is minimal, but are they completely connected or only partially? I know underhood temps will influence both but if you have a bigger radiator, oil cooler etc, does that actually help IAT or just keep the coolant/oil cooler? A bigger more effective radiator could actually increase underhood temps by extracting more heat which ends up in the engine bay. I would have thought to get good results from an improved radiator you absolutely need some venting.

Given where the turbo sits, I would have thought a blanket would help with IATs, but I hear middling stories about that.

 

[QuasarMotors]

Agree completely.

Just thinking about this issue some more.

We seem to have 2 overheating issues, 1) with limp mode and engine temps causing the computer to pull some power and 2) with the computer pulling power due to higher IATs,. I know this sounds stupid coming from a guy who's knowledge of turbos is minimal, but are they completely connected or only partially? I know underhood temps will influence both but if you have a bigger radiator, oil cooler etc, does that actually help IAT or just keep the coolant/oil cooler? A bigger more effective radiator could actually increase underhood temps by extracting more heat which ends up in the engine bay. I would have thought to get good results from an improved radiator you absolutely need some venting.

Given where the turbo sits, I would have thought a blanket would help with IATs, but I hear middling stories about that.

I have a track day this Friday and ambient temps are going to be in the low 90s so I am hoping to collect some good data for the mods I have now vs the mods I plan to do. I currently have PRL IC & CPs, bigger turbo w/ blanket (also ceramic coated), ceramic coated DP / FP, heat shield on DP, Koyo Rad, Acuity reverse flow lines, Rampage Ti intake, PRL HVI. I will see if these are currently enough on a HOT day.

From my understanding the only correlation between IATs and ECTs is with lower IATs you can create more power which in turn creates more heat raising your ECTs. There is also the problem of where all these parts are in the engine bay as well and heat soak.

IATs can be lowered by many small changes. Bigger intercooler, heat wrapping the charge pipes, getting cooler air from intake, heat extraction from engine bay, etc.
ECTs can be lowered by a bigger radiator, better air flow through the radiator, and what I feel is reversing the coolant flow through the radiator as well. Oil cooler is only beneficial for keeping your oil temps in check and will not help ECTs or IATs.

What I am going to try after this Friday is increase the airflow through the intercooler and radiator by making ducting so air can't pass around them increasing their efficiency. Then to allow this air to escape have a vented hood just behind the radiator (over intake/turbo).

 

[Gansan]

I have a track day this Friday and ambient temps are going to be in the low 90s so I am hoping to collect some good data for the mods I have now vs the mods I plan to do. I currently have PRL IC & CPs, bigger turbo w/ blanket (also ceramic coated), ceramic coated DP / FP, heat shield on DP, Koyo Rad, Acuity reverse flow lines, Rampage Ti intake, PRL HVI. I will see if these are currently enough on a HOT day.

From my understanding the only correlation between IATs and ECTs is with lower IATs you can create more power which in turn creates more heat raising your ECTs. There is also the problem of where all these parts are in the engine bay as well and heat soak.

IATs can be lowered by many small changes. Bigger intercooler, heat wrapping the charge pipes, getting cooler air from intake, heat extraction from engine bay, etc.
ECTs can be lowered by a bigger radiator, better air flow through the radiator, and what I feel is reversing the coolant flow through the radiator as well. Oil cooler is only beneficial for keeping your oil temps in check and will not help ECTs or IATs.

What I am going to try after this Friday is increase the airflow through the intercooler and radiator by making ducting so air can't pass around them increasing their efficiency. Then to allow this air to escape have a vented hood just behind the radiator (over intake/turbo).

I think your analysis of the situation is right on. I would only add a reminder that the bigger intercooler directly impedes air from going through the radiator which also makes ECT worse, and the intercooler also is sending hot air to the radiator, again worsening ECT. For reliability's sake, ECT should be the prime concern on the track.

 

[QuasarMotors]

I think your analysis of the situation is right on. I would only add a reminder that the bigger intercooler directly impedes air from going through the radiator which also makes ECT worse, and the intercooler also is sending hot air to the radiator, again worsening ECT. For reliability's sake, ECT should be the prime concern on the track.

Ahh yes forgot about this! Expanding on why I feel the Acuity reverse flow coolant hoses are a big benefit because of this.

 

[Boosted_01_R]

Spal fans with a proper fan shroud, if you haven't already, you should see a good reduction. Run Spal fans on my 600WHP ITR and my 2JZ S30, wouldn't run anything else. 100+ octane on stock tune. You seem like you care more about consistency than power if your benching the other car. Flash a tune and run 2psi less than stock.

 

[QuasarMotors]

Spal fans with a proper fan shroud, if you haven't already, you should see a good reduction. Run Spal fans on my 600WHP ITR and my 2JZ S30, wouldn't run anything else. 100+ octane on stock tune. You seem like you care more about consistency than power if your benching the other car. Flash a tune and run 2psi less than stock.

This would only be good for at idle though and not as speed.

 

[Boosted_01_R]

If your fan can flow more CFM, they will be less of a restriction at higher speed. With a good fan and shroud you can use air more efficiently. Especially when you have a intercooler blocking / heatsoaking the largest air flow path slowing air flow. Has anyone tried a proper shroud/fan setup ?

 

[Dave B]

Just got back from a track day at Shannonville which is interesting for a flat track but not overly fast. Only 2 flat out corners in 4th gear and hit 5th gear once. Using my Trackspec front hood vent and LogR as well as Garmin Catalyst in 85 F temps but pretty high humidity. Engine and cooling is totally stock other than the vent.

Coolant temps hit 225 but very quickly came back to 195 if backing off. Oil hit 266 but slower to return to below 240. OTOH, no limp mode and power seemed pretty good although IATs hit 136. (Would certainly like to drop that one)

Interesting points. A few other CTRs were there. One with lots of engine mods and no vents but a Koyorad who couldn't really run more than one lap. and another 2020 with a stock motor and rad but the more aggressive race louver vent with no significant overheating although he was not using LogR so can't really be sure. Both myself and the guy with the Racelouver were able to run the longest sessions but we also were the only ones with stock engines.

 

[bizlipkick]

Just got back from a track day at Shannonville which is interesting for a flat track but not overly fast. Only 2 flat out corners in 4th gear and hit 5th gear once. Using my Trackspec front hood vent and LogR as well as Garmin Catalyst in 85 F temps but pretty high humidity. Engine and cooling is totally stock other than the vent.

Coolant temps hit 225 but very quickly came back to 195 if backing off. Oil hit 266 but slower to return to below 240. OTOH, no limp mode and power seemed pretty good although IATs hit 136. (Would certainly like to drop that one)

Interesting points. A few other CTRs were there. One with lots of engine mods and no vents but a Koyorad who couldn't really run more than one lap. and another 2020 with a stock motor and rad but the more aggressive race louver vent with no significant overheating although he was not using LogR so can't really be sure. Both myself and the guy with the Racelouver were able to run the longest sessions but we also were the only ones with stock engines.

Off topic (good info btw), what led you to sell your Z06? Also, I was looking at the track spec vent also, did you put it on your hood or order another oem hood?

 

[Dave B]

The Z06 is clearly a lot faster in a straight line but has totally inadequate brakes, a clunky shifter, poor seat, and lousy aerodynamics. It was also getting old and there are more than a few reasons that no one has copied the transverse spring suspension that I believe is unique to Corvettes. I am now 67 and the twitchiness of the Corvette rear end under braking or aggressive corner exit was making me more nervous and likely slowing me down. The CTR is a much more livable car, 16 years newer, and my lap times are not that much slower than the Corvette and I am still not used to the car yet. I was only driving the Corvette around 2000 miles per year, at least half of which were track miles, and needed a car I could enjoy more often. Also, I got a great offer on the car. It depreciated the least of any vehicle I have owned.

I bought another OEM hood and put the Trackspec front vent in (not the side ones). Does it help? Absolutely. Is it enough? No. Either I move to the RaceLouver vent or a better radiator of both. Given that the oil temps the computer thinks I am getting to, take a while to drop, I may need an oil cooler as well but I am just not that impressed about where they can be mounted to be really effective. Likely a topic for another thread specific to effectiveness of the oil coolers available

 

[dsm_mikey]

Off topic (good info btw), what led you to sell your Z06? Also, I was looking at the track spec vent also, did you put it on your hood or order another oem hood?

Whoops...I thought you were referring to me!

I recently sold my C6 Z06 as well...

I loved the C6 Z06! Awesome car. I just realized that with the 2007 Z06, 2016 GT350R, 2005 350z, 2007 S2000, and the 2021 CTR it was just too much. I will be selling at least one more car in the near future. I would rather have less cars that I drive more.

I love cars, but it just feels kind of dumb to have so many. I know people that have more cars than me and I just don't have any desire to own more. I have a family and would rather spend more time with them than driving around by myself! Hence the CTR...4 door.

I think racing with Champcar has really changed my perspective. Racing wheel to wheel is so much more than HPDE events or "canyon carving". I do still enjoy HPDE events and introducing new people to driving on track.

The CTR will be great once I sort the cooling issues. My next test (Added large race louvers hood vent, aftermarket grill with larger opening, and changing back to the oem intercooler and running a C&R track spec radiator)will be 2 open track days Sep 1 & 2.

Pluses: 4 door, cheap to run, and under warranty. My girls love riding in it and I even got them out on Road America in it for a couple parade laps so they can experience race track with daddy.

Negative: F'n cooling issues.

As I said...C6 Z06 is awesome. Love that car and now that I am typing this I am really missing it more! If you are looking for one, make sure you buy one that is well sorted. There are a lot of expensive issues with them that need to be addressed.

 

[Dave B]

My car was a C5 Z06 so down 100hp from a C6 and the C6 certainly has better brakes. Agree that Champcar or other endurance racing is a hoot but that can quickly become a money (and time) pit as well. Ask me how I know.

In Time-Attack events, you are competing against yourself as well as others fairly if the car classification is good. The CTR is a great vehicle to do that with (except for the cooling)

 

[Yomny]

Mind you, I didn't read any of the first 4 pages to be completely honest in case it has been brought up. It seems to me the main issue is getting heat out of the engine bay. Has anyone tried a ridiculous amount of vents on the hood or something along these lines. I was actually considering a track only hood, massively vented, without any other cooling mods. Seems to me, based on reading around, most cooling upgrades barely get any real improvements.

Something like this from Evasive? Or any other brand.

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