Finally cooled down in Vegas. I had a chance to take apart the stock intake system and made some observations that are THEORETICAL in nature only. Please....no flames.
Stillen and JWT (G35 version) are not "closed box" systems. They still draw air from within the engine compartment much like the Injen. But unlike the Injen, they still get some fresh air from the factory intake paths. Of course, this incoming fresh air is cooler.
Injen in CAI mode draws air from the bottom of engine bay. This area is not a "dead air " area. Keep in mind that the radiator fans are drawing massive amounts of air from outside of the grill and flushing it out to the bottom and exiting from the suspension openings and the rear towards firewall. So there is air circulating. I am not sure if removing the underbelly shield will make a lot of difference in the amount of air moved since the opening around the suspension and rear towards firewall are quite large. We may have a "positive pressure" area inside engine compartment from radiator fans forcing air out which may be a good thing! Take a look at your computer's cooling setup and you'll understand what I mean.
My thought on the Stillen and JWT is that the air will take the path of least resistance. Meaning, even though it gets some fresh air from the factory openings, the radiator fans are drawing much more air (stick your hand behind the fans and you'll see what I mean---BUT BE CAREFULL I AM NOT RESPONSIBLE FOR INJURIES. DO AT YOUR OWN RISK!!!) from the outside into the engine compartment. Since this is not a "closed box" sytem-it is sucking in this air
I understand that the air the radiator fans draw is warmed up since it has to pass through the radiator. So, I believe that the JWT/Stillen/Injen pretty much sucks in the same temperature air from within the engine compartment. The Stillen and JWT might be slightly lower and this may only be negligible.
This leads me to my final thoughts about the Injen:
1) Does the longer tubing have a negative effect?
2) How critical is the positioning of the MAF sensor? The JWT and Stillen has it at the factory location while the Injen has it higher upstream.
What are your thoughts?
Stillen and JWT (G35 version) are not "closed box" systems. They still draw air from within the engine compartment much like the Injen. But unlike the Injen, they still get some fresh air from the factory intake paths. Of course, this incoming fresh air is cooler.
Injen in CAI mode draws air from the bottom of engine bay. This area is not a "dead air " area. Keep in mind that the radiator fans are drawing massive amounts of air from outside of the grill and flushing it out to the bottom and exiting from the suspension openings and the rear towards firewall. So there is air circulating. I am not sure if removing the underbelly shield will make a lot of difference in the amount of air moved since the opening around the suspension and rear towards firewall are quite large. We may have a "positive pressure" area inside engine compartment from radiator fans forcing air out which may be a good thing! Take a look at your computer's cooling setup and you'll understand what I mean.
My thought on the Stillen and JWT is that the air will take the path of least resistance. Meaning, even though it gets some fresh air from the factory openings, the radiator fans are drawing much more air (stick your hand behind the fans and you'll see what I mean---BUT BE CAREFULL I AM NOT RESPONSIBLE FOR INJURIES. DO AT YOUR OWN RISK!!!) from the outside into the engine compartment. Since this is not a "closed box" sytem-it is sucking in this air
I understand that the air the radiator fans draw is warmed up since it has to pass through the radiator. So, I believe that the JWT/Stillen/Injen pretty much sucks in the same temperature air from within the engine compartment. The Stillen and JWT might be slightly lower and this may only be negligible.
This leads me to my final thoughts about the Injen:
1) Does the longer tubing have a negative effect?
2) How critical is the positioning of the MAF sensor? The JWT and Stillen has it at the factory location while the Injen has it higher upstream.
What are your thoughts?