Intake Air Temps Measured

[Jack B]

There has been a lot of discussion if the oem IAT actually indicates true intake air temp. The following data is extremely accurate, however, it also raises some further questions. We now know that actual air temp in the intake tubes does not align with the displayed value of IAT. It may not matter, SRT has probably done the same experiment and then developed a correction algorithm.

One thing this proves, is that the air in the intake tubes is relatively hot and that insulating the air box and/or tubes should bring some benefit.

Some things we do not know are:

1. How long it takes the IAT and the true tube air temps to drop when you are under way.

2. How much the temps drop.

3. How much an ambient of 80F affects this data, I would guess most of these temps would increase by at lease 30F.

IAT Temps 11-2013.jpg



Insulating the intake system has been mentioned in previous threads and should help lower the overall intake air temps. Another part to the puzzle should be a plate below the airbox that keeps the hot radiator air off of the box. I took measurements and will put a plate in very soon. T

The plate will measure 18" wide by 16" long. Starting at the front, the plate will run 3", then, be bent at approximately a 25 degree angle down. The two fasteners that hold the airbox in place will hold the top of the plate. A piece of 3M trim tape will hold the plate to the the frame cross member.

With the combination of the airbox insulation and the plate, the intake air temp has to drop.

[SSGNRDZ_28]

Jack - thanks for the measurements and insight. As you and others have hinted at, the root of the problem is the intake air getting hot (sensor measurements / readings / calibrations aside). Shielding / insulating the intake as much as possible should help performance across the board. I’ve been keeping up with these threads and am looking forward to the results of experiments others are performing as well.

I am in the process of developing a heat shield for the Gen IV and V intake / air box. This shield is being designed to reduce thermal convection and radiation seen by the air box. I hope to make this available at a reasonable price sometime in January. The fit / finish will be top notch, motorsport spec, etc. within reason to maintain affordability. Many materials are being considered and those that offer the best gains and price will be what ultimately makes it into the final design.

As of now the air box has been scanned with a 3D laser scanner to create a CAD model and the heat shield will be made to fit exactly without altering the position of the box or modifying the car. My next step will be to produce a prototype and test on the car by logging IAT and other parameters while idling/running/etc. to prove the function and benefits. I will also be using a thermal imagining camera to help highlight the effectiveness and assist with the design process. I’ll keep everyone updated once I have more information.

[ViperSmith]

Thanks for the baseline jack. interested to see where it goes when you work your magic

[Voice of Reason]

Jack, would there be any benefit to insulating the plate you're making in addition to insulating the air box itself? Could that help reflect even more heat away?

[Jack B]

The plate is just to deflect the direct air from the radiator. Since you cannot seal the area, insulation will have little affect. There will be a nice air space between the airbox and the plate.

Jack, would there be any benefit to insulating the plate you're making in addition to insulating the air box itself? Could that help reflect even more heat away?

[ViperTony]

Jack, did you make this plate a long time ago for your GenII?

[Jack B]

Yes I did, however, that plate was far more complicated, the one for the G5 will be simple.

Jack, did you make this plate a long time ago for your GenII?

[Voice of Reason]

The plate is just to deflect the direct air from the radiator. Since you cannot seal the area, insulation will have little affect. There will be a nice air space between the airbox and the plate.

When you were measuring for the plate did you notice if there was any way to direct the air up out the hood vents? The more air we can channel out of the hood the cooler we can keep everything. Just a thought...

[SSGNRDZ_28]

When you were measuring for the plate did you notice if there was any way to direct the air up out the hood vents? The more air we can channel out of the hood the cooler we can keep everything. Just a thought...

From looking at the Gen IV if you angle the edges of the heat shield upward around the air box it would help to direct the air out to the air vents on the hood. I think taking the plastic grilles out of the hood vents would improve the cooling further. This is something I may try to quantify in my testing.