Aftermarket air filters revisited

[Steve M]

I have had a slightly different experience with the IATs. I monitor IAT closely, and like others have said, timing is pulled at fairly low temps - 80 degrees or so is about right. Here in the hot desert, my car will start out fairly close to ambient, and while driving the first time will build to 12-15 degrees above, regardless of speed. The IAT does not decrease with increased speed. After I shut the motor down, the IAT sensor appears to heat soak and when I restart the car, the IATs will be 25+ degrees above ambient and never recover much to a lower ambient to displayed IAT differential. I have seen IATs as much as 40 degrees over ambient! This is without shielding on the air box or IAT sensors. Since the IAT sensor is basically integral to the MAF sensor, it would be difficult to move it upstream into the incoming air, but that would help. I think heat soak of the sensor is causing artificially high readings, and that is a horsepower killer. I realize heat shielding would help some, but I doubt it would do much to prevent heat soak from a hot engine after it is shut down (I do open the hood while the car sits). On a typical hot, but not extreme day, I have run the first early morning session feeling pretty strong. After that, the car is such a slug that I generally just park it.

Pappy

Good info...thanks for adding good data to this discussion.

[Dan Cragin]

Back in the day we experimented with a "Pre Chiller" which used the AC system to cool the intake charge. Even though the AC system put a load on the system, it did keep the power much more consistent, more so on our supercharged cars.

[ViperGeorge]

I have had a slightly different experience with the IATs. I monitor IAT closely, and like others have said, timing is pulled at fairly low temps - 80 degrees or so is about right. Here in the hot desert, my car will start out fairly close to ambient, and while driving the first time will build to 12-15 degrees above, regardless of speed. The IAT does not decrease with increased speed. After I shut the motor down, the IAT sensor appears to heat soak and when I restart the car, the IATs will be 25+ degrees above ambient and never recover much to a lower ambient to displayed IAT differential. I have seen IATs as much as 40 degrees over ambient! This is without shielding on the air box or IAT sensors. Since the IAT sensor is basically integral to the MAF sensor, it would be difficult to move it upstream into the incoming air, but that would help. I think heat soak of the sensor is causing artificially high readings, and that is a horsepower killer. I realize heat shielding would help some, but I doubt it would do much to prevent heat soak from a hot engine after it is shut down (I do open the hood while the car sits). On a typical hot, but not extreme day, I have run the first early morning session feeling pretty strong. After that, the car is such a slug that I generally just park it.

Pappy

Exactly! That is why I wish there were a way to cool the intake charge, not fool the sensor, but actually lower the temp of the incoming air. Besides the DEI solution there was another one I saw that used cooling tubes around the air intake or something like that. I can't find the link though. I think someone on here posted it though.

Solving this issue and being able to lower intake air temps would be HUGE!! It would unleash the power the engine has to offer. AND we know it can be solved since SRT did it with the Demon by using the A/C to cool the intake charge.

[sharmut]

Would love to see one for the Viper NA.

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[Topplayer]

I have wrapped insulation around my IAT sensors and I use DSE's airbox heat shield. I also insulated the bottom of the airbox. My headers are Swain coated. The reason I say this is that the ECM pulls timing as IATs and coolant temps rise. I read somewhere that it starts pulling timing when IATs exceed something like 80 degrees. Given this we are all losing power as the engine heats up or the air it takes in heats up.

If someone could develop a way of better controlling IATs we would gain power when the engine is warm. There was a company I saw that built water cooling jackets/coils for the intake. Maybe something like that or some better way of insulating the IAT sensors would make more sense than a different air filter. Jack did have a device that fooled the ECM to think IATs were cooler than they really were but he discovered a knock problem and pulled the plug so to speak.

This looks interesting but maybe complicated to install on a Viper.

https://www.designengineering.com/air-intake/

do you have a picture of your wrapped IAT sensors? I have thought about different ways to do this but I want it to look professional!

[ViperGeorge]

do you have a picture of your wrapped IAT sensors? I have thought about different ways to do this but I want it to look professional!

Mine do not look professional. I simply wrapped some silver insulation mat from DEI around the them and zipped tied it on. I too would love to have someone build some kind of insulated box or something that could mount over them and look OEM.

[Topplayer]

Mine do not look professional. I simply wrapped some silver insulation mat from DEI around the them and zipped tied it on. I too would love to have someone build some kind of insulated box or something that could mount over them and look OEM.

fair, BJG32 built like a box around them. I remember seeing it on the boards once.

[sharmut]

Found the thread below and will redo mine with the gold material.

https://driveviper.com/forums/thread...n-Lowering-IAT

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