Intake Air Temperature, To calculate potential power loss due to increased temp Options

[pvollma]

As an experiment, I set up my grill meat thermometer with the probe right in front of the air intake on my stock 76 2.0, with the digital display stashed above the passenger seat (probe cord was only long enough to reach there). Wish I had one of the wireless ones, but maybe next time. I then drove the car about 20 miles on the interstate. The device can be set to a desired temperature, and will beep when that temperature is reached. I set it to 130 degrees, and it started beeping about a mile before I got off, and continued to beep for a minute or so after that. The ambient air temperature was about 40 degrees, so that's at least a 90 degree increase, or about a 10% horsepower loss if you use the SAE formula for dyno correction of 1.1% for every 10 degree increase in temperature.

This is a follow-on from my post asking about experiences with a guy selling a cold air intake kit, but I'd be curious if my experience can be duplicated by others. It would seem like getting cold(er) air to the intake would be a good improvement to make.

[Dave_Darling]

http://members.rennlist.com/demick/coldair.html

[Rand]

http://members.rennlist.com/demick/coldair.html

There was a detailed thread on here I remember but can't find. I tried searching threads with "cold air intake" written by demick. No luck. This topic had a rich history here. I hate to see that lost, but the search function on this forum is weak.

FWIW, maybe there's something useful in these "results." --->

http://www.914world.com/bbs2/index.php?act...cold+air+intake

[Matt Romanowski]

Here is a chart from a day at Pocono last fall. The lower temp is the ambient measured in the cabin. The red line temp is in the engine compartment. Green is the speeds. You can see the one large increase is when the car stopped for a bit. We are running a 3 liter six in the track car.

[brant]

the AJRS built race cars were all running clear lexan duct work for a while

-it was air grabbed from the roof

-a duct work from the inside of the roof and down through where the rear window would normally be. a square duct about 1 square foot in ID

-then dumped into the intake.... ala mini ram air

I don't think air from underneath the car would be nearly as good
the stock motor cooling system dumps hot air under the car
clean air above the car would be better

part of the AJRS strategy was also that these race motors were converted to electric fans, so this additional air was a cooling aid also
(even the 3.3L race motors with 350+ HP were converted to electric fans)

[brant]

Matt,

1) how long of a session?

it looks like once the temp leveled off around 110(F) it sorta stayed there?
2) (is that peak at 110F?)

3) what was the ambiant that day?
4) do you run a rear window in the car?

thanks in advance
brant

[JamesM]

As an experiment, I set up my grill meat thermometer with the probe right in front of the air intake on my stock 76 2.0, with the digital display stashed above the passenger seat (probe cord was only long enough to reach there). Wish I had one of the wireless ones, but maybe next time. I then drove the car about 20 miles on the interstate. The device can be set to a desired temperature, and will beep when that temperature is reached. I set it to 130 degrees, and it started beeping about a mile before I got off, and continued to beep for a minute or so after that. The ambient air temperature was about 40 degrees, so that's at least a 90 degree increase, or about a 10% horsepower loss if you use the SAE formula for dyno correction of 1.1% for every 10 degree increase in temperature.

This is a follow-on from my post asking about experiences with a guy selling a cold air intake kit, but I'd be curious if my experience can be duplicated by others. It would seem like getting cold(er) air to the intake would be a good improvement to make.

Sounds about right. Nice thing about megsquirt, you can see this at all time. My MS setup on my 2.0 with all stock intake and sensor usually reads around 140-160 deg in the plenum.

Also why I have been thinking about jet-hot coating the plenum, runners, and air box.

[Matt Romanowski]

Matt,

1) how long of a session?

it looks like once the temp leveled off around 110(F) it sorta stayed there?
2) (is that peak at 110F?)

3) what was the ambiant that day?
4) do you run a rear window in the car?

thanks in advance
brant

I don't remember what session this was, but it was probably 20 minutes. It leveled off around 100. The red triangle is the max at 110F. Ambient was the blue line at 60ish. We do have a rear window.

[r_towle]

Wow, 60 outside and 100 in the engine bay....

Time for some ducts...