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reducing C6 under hood temperature

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Old Aug 3, 2023 | 09:50 PM
  #21  
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Default Not so sure

I'm probably gonna get some crap for this but, my understanding is that things like a 160 degree thermostat and removing the heat shields under the plastic coil covers doesn't help the engine produce more hp. I talked to an engineer from Chevrolet when the Bloomington Gold event was held at the Indy Raceway. He said the LS engines are designed to run hotter that the old school small blocks. He referred to oil flows and fuller combustion burns when at the proper operating temp, which can be defeated with a 160 degree thermostat. I did try one, and saw no difference, but I'm not sure I know enough to question the guys who designed these engines. So I put the original back in and have had no problems.
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Old Oct 26, 2023 | 05:59 PM
  #22  
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Originally Posted by tahoe
heatshield products : Is this the company? Reviewed 3/2016 motortrend

heatshield products i-m shield

test: More horsepower for less

more horsepower for less: Heatshield products i-m shield thermal barrier can add 20 hp and 20 lb-ft of torque to your vette for just $50! Test showed 43 degree temp drop on intake manifold

i can not document or verify this claim.
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Old Oct 27, 2023 | 02:35 AM
  #23  
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Originally Posted by HOXXOH
Simplest and least expensive method ($0) is to remove the rear (cowl) rubber seal. While stopped and at low speeds heat escapes out the top and at higher speeds cooler air enters and pushes the hot air out the bottom.
Originally Posted by Matt Marshall
I just removed mine last night and will see how it does later today.
100% WRONG approach. That seal is there for a reason. The area at the back of the hood / base of the windshield is a HIGH-PRESSURE zone, meaning, removing the rubber seal at the back of the cowl will allow air to force IN under the hood, increasing engine bay pressure, effectively REDUCING the airflow through the radiator, ie: the front of the car is also a high-pressure zone, and it's the high-low differential which maximizes flow through the rad.

My old Camaro track car was setup by a "creative" individual who tried for everything light-weight and to make the car as track-worthy as possible. However, it had a MASSIVE overheating problem. It took an experienced racer to notice that I had no seal at the rear of the cowl. Once I replaced it, my engine temps went from ~230°+ down to a very manageable ~190 - 200°. It was night-and-day.

A vented cowl, on the other hand, is allowing airflow out in the MIDDLE which is BEFORE the high-pressure zone at the rear of the cowl, thus, it does not adversely affect the cooling flow, rather, improves it .
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Old Oct 27, 2023 | 05:04 PM
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Default Reducing air intake temp. on C6 Grand Sport for HP gain

Originally Posted by Tahoe
i can not document or verify this claim.
Dodge Demon uses an intercooler (A/C) to decrease air temp & increase intake air density = HP +++. Any comments on (1) insulating the underside of the intake manifold?
(2) ceramic-coated headers to reduce underhood temp
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Old Oct 27, 2023 | 08:33 PM
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Originally Posted by Tahoe
Dodge Demon uses an intercooler (A/C) to decrease air temp & increase intake air density = HP +++. Any comments on (1) insulating the underside of the intake manifold?
(2) ceramic-coated headers to reduce underhood temp
I was looking around for intake manifold heat shields recently, here's one for example :
Intake Manifold Heat Shield LS3 (140021) - Gwatney Performance

Not certain if it's worth the coin. I've also seen a YouTube video of a guy laying a rectangular cut piece of heat shield directly on the valley plate to stop heat at that location. Maybe the intake heat shield AND the heat shield on the valley plate would work well at reducing intake manifold and under hood temps ???
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Old Oct 27, 2023 | 11:20 PM
  #26  
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Originally Posted by Dzv69
I was looking around for intake manifold heat shields recently, here's one for example :
Intake Manifold Heat Shield LS3 (140021) - Gwatney Performance

Not certain if it's worth the coin. I've also seen a YouTube video of a guy laying a rectangular cut piece of heat shield directly on the valley plate to stop heat at that location. Maybe the intake heat shield AND the heat shield on the valley plate would work well at reducing intake manifold and under hood temps ???
Thank you.. Summit has an $80 shield for LS3....waiting for more forum feedback
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Old Oct 29, 2023 | 02:40 PM
  #27  
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Originally Posted by Cap'n Pete
100% WRONG approach. That seal is there for a reason. The area at the back of the hood / base of the windshield is a HIGH-PRESSURE zone, meaning, removing the rubber seal at the back of the cowl will allow air to force IN under the hood, increasing engine bay pressure, effectively REDUCING the airflow through the radiator, ie: the front of the car is also a high-pressure zone, and it's the high-low differential which maximizes flow through the rad.

My old Camaro track car was setup by a "creative" individual who tried for everything light-weight and to make the car as track-worthy as possible. However, it had a MASSIVE overheating problem. It took an experienced racer to notice that I had no seal at the rear of the cowl. Once I replaced it, my engine temps went from ~230°+ down to a very manageable ~190 - 200°. It was night-and-day.

A vented cowl, on the other hand, is allowing airflow out in the MIDDLE which is BEFORE the high-pressure zone at the rear of the cowl, thus, it does not adversely affect the cooling flow, rather, improves it .
Yes, it could be wrong for a track car, but certainly not wrong for a typical street driven car, where underhood temperature variations of +/- 20 degrees can happen in a matter of minutes. In normal city traffic, you only occasionally get over 30 mph to take advantage of ambient air temps forced in by the cowl pressure zone. However, no hood seal also provides an additional escape route for hot air while waiting for the traffic light to change. That also keeps the AC from being overworked and adding heat to the engine coolant. This doesn't apply to outside temps below 70, since you don't have the AC on either.
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Old Oct 29, 2023 | 04:17 PM
  #28  
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Originally Posted by Dzv69
I was looking around for intake manifold heat shields recently, here's one for example :
Intake Manifold Heat Shield LS3 (140021) - Gwatney Performance

Not certain if it's worth the coin. I've also seen a YouTube video of a guy laying a rectangular cut piece of heat shield directly on the valley plate to stop heat at that location. Maybe the intake heat shield AND the heat shield on the valley plate would work well at reducing intake manifold and under hood temps ???
DIY heat shield (you can use double thickness): Heat Shield Adhesive Backed Aluminized Fiberglass Heat Sheet Protection Barrier Cover Aluminized Heat Shielding Mat for Auto Use Heat Insulation Sheet Heat Reflective (Silver, 36 x 48 Inch)

WISAUTO Aluminized Heat Shield Thermal Barrier Adhesive Backed Heat Blanket (12'' X 24'') $14.



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Old Oct 29, 2023 | 04:23 PM
  #29  
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Originally Posted by Tahoe
DIY heat shield (you can use double thickness): Heat Shield Adhesive Backed Aluminized Fiberglass Heat Sheet Protection Barrier Cover Aluminized Heat Shielding Mat for Auto Use Heat Insulation Sheet Heat Reflective (Silver, 36 x 48 Inch)

WISAUTO Aluminized Heat Shield Thermal Barrier Adhesive Backed Heat Blanket (12'' X 24'') $14.

Excellent, definitely worth some heat reduction.
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Old Oct 29, 2023 | 10:52 PM
  #30  
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I would say header either stock or aftermarket are your biggest heat producers. So if they were coated/wrap with some kind of heat reducing material this would lower temps a lot. Also if you had some way of venting that out the sides.
The vents in hood would not do much during forward motion as the high pressure would come in effect. Now stopped they would help
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Old Oct 29, 2023 | 10:53 PM
  #31  
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From another board
A friend of mine has a '37 Ford coupe street rod with a 400 Chevy engine, power steering, AC etc. It would run about 210-215 on a hot day and it always worried him. His car had the louvered hood sides so I talked him into taking them off and trying it that way. With out the sides it dropped below 200 so he would just put them in the trunk and then put them back on when he got to the car show.
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Old Oct 30, 2023 | 12:42 PM
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Originally Posted by sirdano
I would say header either stock or aftermarket are your biggest heat producers. So if they were coated/wrap with some kind of heat reducing material this would lower temps a lot. Also if you had some way of venting that out the sides.
The vents in hood would not do much during forward motion as the high pressure would come in effect. Now stopped they would help
The area near the windshield base and hood/cowl only is high pressure above roughly 30 MPH on a C6. Below that, it's either low pressure or neutral, depending on the proximity to the hood/windshield intersection and car centerline. Wind tunnel data shows flow and turbulence, yet requires more than vapor to show high/low pressure areas. You don't need a wind tunnel, since you can see the air directional flow and intensity by using the simple yarn test and driving your car. It's aerodynamics 101.
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Old Oct 30, 2023 | 01:54 PM
  #33  
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The intake manifold heat shields delay the bottom of the intake manifold getting up to the operating temp of the rest of the engine. They don't prevent that from happening. If they had pressurized freon running through them, it would be different. They don't.
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Old Oct 30, 2023 | 04:21 PM
  #34  
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Great point, Thank you. You save me from wasting $ & time. I'll concentrate on my insulated, sealed intake shroud that faces the NACA duct.
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