Efficiency of "intakes" on turbo cars... your thoughts?

[Brent]

I thought this would be a good discussion. I am referring to where the air filter is located(or draws air from) and not the intake manifold. What are your thoughts about where it should be located and why... and does it really matter? To start with the basics: I know a lot of people think that the concept of drawing air from a place other than the engine bay is worthless because the air is hitting the turbo which is going to be hot and the results will be negligible at best. The intercooler will do the majority of the cooling before it hits the throttle body so it does not matter where the "intake" or filter is located.

I agree that the intercooler is the largest air cooling factor, but does anyone have actual results/documentation about location of the intake?

I am a reliability person which basically means I focus on a couple of things:
1. Temperature Control: (Oil, Water, Air, and fuel) Which all work together to keep engine temps down as a whole.
2. Sufficient Fuel: ie I keep the boost relatively low on my T78(12-14psi)

I also believe that pulling cold/ambient air(unless it is extremely hot outside) is only going to help. However, I would like to know how much. I plan on finding out how much. I am hoping to fabricate what I like to call a "track" intake for my Silver FD for track days. I plan on relocating my AIT to the cold side of the intercooler pipe. I haven't decided where yet... while locating right next to the intercooler on the cold side pipe will tell me exactly how cold the air is coming out of the intercooler, what I really want to know is how cold the air is as it enters the engine(without the AIT being effected by heat soak). I will test my current intake which is basically sitting in the engine bay. I then plan on fabricating a pipe that leads to the front bumper opening, attach a filter, and make a duct out some aluminum and rivets. This obviously isn't practical for street use and would only be used while tracking the car. It will be similar to the Pan Speed Car(only they don't run an air filter). Here are a couple of pictures that are similar to what I'll be making... unless someone shows me evidence that it is completely pointless. As for the rest of the main components of my cooling setup: I run a Pettit CoolCharge III Intercooler, a Koyo N Flo Radiator, and I will be adding a stock passenger side oil cooler as soon as I get home in October.

PanSpeed Time Attack FD's Intake:


You can see the duct at the front passenger side of the bumper:


Jack Mardikian's RX-7 that ran 1:48.5 at Button Willow during the 2007 Super Lap battle, notice filter in bottom left:

[Phoenix7]

I'm doing the same thing with my FC. Hope to take advantage of this topic.

here is another pic of the last car you posted.

[David Jerome]

I am going to make a cold air intake for my car, but I plan to run water injection and no intercooler. From my readings in teh past it definitely makes a difference in air intake temps especially considering on the fd if you dont run a intake box or make your own custom cold air intake the filters are just sucking in air straight off of the radiator. Also, we all know how warm the engine bay of an fd can and does get.

[Whizbang]

well im am going to exaggerate some numbers to get my point across.

Say you have 50 degree air coming into the filter that is located out of the engine bay(nice cool night). Thermodynamically speaking, yes, the turbocharger will compress the air which generates heat, and there will be some heat absorption from the the turbo itself and the intake and inter cooler piping. Then obviously the inter cooler will do its job so on and so forth.

But all of the heat coming into the intake track will be consistent more or less given the engine is performing the same operations. Heat transfer is dependent on time and air isnt a great conductor of heat so most of your temperature increase is from the air being compressed.

so if you are pulling air from a hotter source, say near the radiator or close to the turbo or worse, when people run the dump tube for the wastegate near the filter, you might be pulling in air that is upwards of 200 degrees. That is a huge temperature differential.

[nissanconvert]

It seems to me, that the cooler the air coming in the filter is, the cooler it will be coming out of the turbo after being compressed and the cooler it will be going in to the intercooler- therefore the cooler it will be coming out of the intercooler.

It may not amount to more than 10 degrees but 10 degrees is 10 degrees