Since this was brought up in a recent thread, I figured I would attempt to do a little testing. The test I've done so far was on my 1993 Grand Prix(3.1 MPFI/naturally aspirated) without an insulator. I've only completed the first part of my testing. Anyways, on to to my method of testing....
NOTES: I have a 180* thermostat in my car. The outside temperature was 70*F.
Test 1: Without Insulator
-I let the car warm up in my driveway for approximately 5 minutes, and then proceeded to drive the car 20 miles.
-When I got home, I immediately popped the hood and then shut off the car. I hopped out with my infrared laser thermometer in hand and started taking temperature measurements.
-All of my hood measurements were taken around the center of the hood from front to back, and that's where it was hottest.
Results:
-Coolant temperature was 172*F at the time of my test.
-The highest temperature I measured on the paint underhood was 97*F. This was near the center of the hood offset just a bit to the right. This area is right inline where the exhaust manifold area is, so it makes sense that it was the hottest area on the hood. The exact center of the hood above the intake plenum was 90*F on average.
-The exterior of the hood measured 69*F, it was just slightly below the 70*F outside temperature.
Now, I plan to retest with my old insulator reinstalled. I plan on driving the car the same distance and waiting to test until about the same time so that the outside temperatures will be very close to what they were before(the temps/weather here have been the same the past few days and will stay the same for two more days according to the forecasts). I suppose that I'll measure the surface temperature of the insulator itself next time and then I'll pop it off really quick and take some temperature readings underneath it to see if the paint under the hood is any cooler.
I will be performing the same tests on my TGP sometime soon so that we will have TGP specific results to discuss.
Super job, interesting it did not get that hot, its not a turbo though eh? Looking forward to the tests on the TGP.
I'm having a hard time time finding an insulator for mine so I would like to just leave it off until I do. I never owned a turbo car before and was surprised how much heat there was under the hood.
:thumb: I gotta give you props, thats a good idea, looking forward to seeing the turbo results