overcooling at the track

quik468 · 09-06-2020, 12:01 PM

What is the coldest you can run without power loss.

This is what happend last friday at the track:

I have a 2017 Camaro 2ss and I changed to a hi-ram from from an MSD. The hi-ram seems to hold more heat than the MSD so I decide to lower under hood temps. I messed with the fan profiles and turned them on at 50% below 195 to take advantage of the 160 degree thermostat. I had it cooled down to 167 engine temp and 158 oil temp. with the fan running at 50% I was able to maintain this temp driving to the staging lanes. Intake air temp and Manifold temps stayed low also. I ran the car and it lost 3.5 tenths in the quarter mile(11.38) at 120mph. I had this happen earlier in the year on a cool night. The previous time I was out it was extremely hot out and I ran 11.06 at over 122 mph. I then decided to fully warm up my car and got the oil temp to 178 and engine temp at 190 as I pulled into the burnout box. Manifold was 112 and the IAT was 90. Ambient temp was 65 at the time of the last run. Car ran 11.02 at over 122.

cmitchell17 · 01-19-2021, 10:32 PM

From a thermodynamic standpoint the colder your coolant temperature the less efficient your motor will be. I have been trying to quantify this through some calculations on just how much horsepower you lose by running a cooler thermostat, say a 160F versus the stock 194F.

In addition, do you know how little heat transfer there is from the manifold and intake to the intake air? It's extremely small and actual is quantified by GM in the tune somewhere you can look at.

I know everyone else is going to tell you different and I don't have any proof, although I want to get some I just need to do some calcs and maybe try to make a simulink model. I think to answer your question though is any time you run "cooler" you lose power (excluding cooler air charge).

If I do a really rough estimation of heat transfer by taking the difference between a 160F coolant temp versus a stock 194F coolant temp, I actually get around 1 horsepower.

quik468 · 01-23-2021, 05:03 PM

Thanks for your input, I have been logging all my runs and the main difference I see is is density altitude. I have cooled the car and also hot lapped it with very little difference in E.T.. Also, because of running E85 I don't see much E.T. change by altitude compared to what I would see being on gas. The one thing I can guarantee is that I can get the car up to operating temperature. I can't guarantee I can cool it off consistently especially in the later rounds. I'm putting my efforts to reducing under hood temps now. I have wrapped the headers and removed the shield under the engine for increased airflow.

cmitchell17 · 01-23-2021, 06:07 PM

Quote:

Originally Posted by quik468

Thanks for your input, I have been logging all my runs and the main difference I see is is density altitude. I have cooled the car and also hot lapped it with very little difference in E.T.. Also, because of running E85 I don't see much E.T. change by altitude compared to what I would see being on gas. The one thing I can guarantee is that I can get the car up to operating temperature. I can't guarantee I can cool it off consistently especially in the later rounds. I'm putting my efforts to reducing under hood temps now. I have wrapped the headers and removed the shield under the engine for increased airflow.

Have you logged your calculated cylinder airmass? I am curious to see what it is.

quik468 · 01-23-2021, 06:48 PM

.93 g peak on the 11.38 pass. .97 g on my best pass of 10.82

BDPhoto519 · 01-25-2021, 11:30 AM

If you are seeing big changes in DA from pass to pass that will account for the performance differences you are seeing.

quik468 · 01-26-2021, 06:11 PM

My next pass was fully warmed up and was an 11.02. I log DA on every pass and with my car I would have to see a 4000ft + change in altitude to account for the ET change.

laynlo15 · 01-28-2021, 07:52 AM

This I happened to me also, these motors need to be at operating temp or close it to make the most power. I had it happen on the dyno also when I only had the engine temp at 155, lost power. I didn't change one thing and got the engine temp to 185 on the next pull and made more power. Intake temps in the 90s to a 100 are really good and should not affect power output unless you have really high intake temps, say over 140 which I doubt you'd see on an NA motor.

KingLT1 · 01-28-2021, 09:42 AM

Agree with Greg. LS/LT engines like to run around 185. This is the temp where they are the most efficient at completing combustion.

L78toLT1 · 01-28-2021, 02:00 PM

Quote:

Originally Posted by cmitchell17

Have you logged your calculated cylinder airmass? I am curious to see what it is.

Enjoy your posts, CMitchell17. If you're not a mechanical engineer then you have missed your calling. Takes one to know one btw

laynlo15 · 01-29-2021, 07:57 AM

Quote:

Originally Posted by KingLT1

Agree with Greg. LS/LT engines like to run around 185. This is the temp where they are the most efficient at completing combustion.

We've both been there.

09-06-2020, 12:01 PM	#1
quik468 Drives: 17 Camaro ss Join Date: Dec 2018 Location: Ohio Posts: 6	overcooling at the track What is the coldest you can run without power loss. This is what happend last friday at the track: I have a 2017 Camaro 2ss and I changed to a hi-ram from from an MSD. The hi-ram seems to hold more heat than the MSD so I decide to lower under hood temps. I messed with the fan profiles and turned them on at 50% below 195 to take advantage of the 160 degree thermostat. I had it cooled down to 167 engine temp and 158 oil temp. with the fan running at 50% I was able to maintain this temp driving to the staging lanes. Intake air temp and Manifold temps stayed low also. I ran the car and it lost 3.5 tenths in the quarter mile(11.38) at 120mph. I had this happen earlier in the year on a cool night. The previous time I was out it was extremely hot out and I ran 11.06 at over 122 mph. I then decided to fully warm up my car and got the oil temp to 178 and engine temp at 190 as I pulled into the burnout box. Manifold was 112 and the IAT was 90. Ambient temp was 65 at the time of the last run. Car ran 11.02 at over 122.

01-25-2021, 11:30 AM	#6
BDPhoto519 Drives: 2018 Camaro 2SS A8 Join Date: Dec 2019 Location: Windsor, Ontario, Canada Posts: 90	If you are seeing big changes in DA from pass to pass that will account for the performance differences you are seeing. __________________ 2018 Camaro 2SS A8 Redline Edition

01-28-2021, 07:52 AM	#8
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,860	This I happened to me also, these motors need to be at operating temp or close it to make the most power. I had it happen on the dyno also when I only had the engine temp at 155, lost power. I didn't change one thing and got the engine temp to 185 on the next pull and made more power. Intake temps in the 90s to a 100 are really good and should not affect power output unless you have really high intake temps, say over 140 which I doubt you'd see on an NA motor. __________________ 2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff

01-28-2021, 09:42 AM	#9
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,793	Agree with Greg. LS/LT engines like to run around 185. This is the temp where they are the most efficient at completing combustion. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA Last edited by KingLT1; 01-28-2021 at 10:12 PM.

01-19-2021, 10:32 PM	#2
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,200	From a thermodynamic standpoint the colder your coolant temperature the less efficient your motor will be. I have been trying to quantify this through some calculations on just how much horsepower you lose by running a cooler thermostat, say a 160F versus the stock 194F. In addition, do you know how little heat transfer there is from the manifold and intake to the intake air? It's extremely small and actual is quantified by GM in the tune somewhere you can look at. I know everyone else is going to tell you different and I don't have any proof, although I want to get some I just need to do some calcs and maybe try to make a simulink model. I think to answer your question though is any time you run "cooler" you lose power (excluding cooler air charge). If I do a really rough estimation of heat transfer by taking the difference between a 160F coolant temp versus a stock 194F coolant temp, I actually get around 1 horsepower.

01-23-2021, 05:03 PM	#3
quik468 Drives: 17 Camaro ss Join Date: Dec 2018 Location: Ohio Posts: 6	Thanks for your input, I have been logging all my runs and the main difference I see is is density altitude. I have cooled the car and also hot lapped it with very little difference in E.T.. Also, because of running E85 I don't see much E.T. change by altitude compared to what I would see being on gas. The one thing I can guarantee is that I can get the car up to operating temperature. I can't guarantee I can cool it off consistently especially in the later rounds. I'm putting my efforts to reducing under hood temps now. I have wrapped the headers and removed the shield under the engine for increased airflow.

01-23-2021, 06:48 PM	#5
quik468 Drives: 17 Camaro ss Join Date: Dec 2018 Location: Ohio Posts: 6	.93 g peak on the 11.38 pass. .97 g on my best pass of 10.82

01-26-2021, 06:11 PM	#7
quik468 Drives: 17 Camaro ss Join Date: Dec 2018 Location: Ohio Posts: 6	My next pass was fully warmed up and was an 11.02. I log DA on every pass and with my car I would have to see a 4000ft + change in altitude to account for the ET change.

User Name		Remember Me?
Password