Any Ram Air advantages on an NA engine


Wrench Pro
Nissan Sunny B15

Are there any advantages to rerouting the air box, where it sits in the engine bay, to an area where it gets the full nose wind for a NA engine?
Thats a great question, the intake air speed is pretty high in a normal engines operation, so there is no appreciable difference until you hit speeds of around 70mph. A larger scoop will be beneficial but you need some of this air through the radiator to cool the engine so it's not practical. The other risk is sucking in water, which will kill your engine if a hydrolock occurs!
A very small advantage! You'd get the same power hike by using a premium fuel or driving when it's 6 degrees colder outside, so not something you'd really notice.

If I had a B15 sunny I would focus on the brakes and suspension and look into a faster road cam profile.

You could always do the TorqueCars airbox mod and smooth it out and drill holes in it for a cheap mod.
The biggest reason on vehicles I've worked on isn't airspeed -- it's temperature. A large proportion of aftermarket air intakes take general engine-compartment air into the engine, which is an awful idea in a Topeka, Kansas summer with outside ambient at 100F / 38C. I am told that a lot of local retrofitters know this, and when they receive complaints, they short out a common sensor (don't remember which, don't care, I think it's one of the oxygen sensors), and the result is at least sufficient to get the complainers off their backs. This has made me quite careful about common retrofits!

But if I could route an intake using a fairly straight big hose to anything truly external and not anywhere near everything hot, I would do so as a high priority. This is why a lot of vehicles take air from a front wheelwell: it's dirty air, but it's significantly cooler than anything else available.

My Tahoe seems to split its intake from both wheelwell and underneath (not very far from an exhaust manifold), and I'm fairly certain there's an automatic flapper to switch back and forth, hopefully by temperature. I could remove all of it and replace with one big hose pointed somewhere, but where? There's just too much in the way. I could have a big slot cut in the hood, but I don't really want to compromise the OEM that much, it's a 1998 with very close to zero rust that has lived in this climate for that long, it must be from a rare run of the mill, and I don't think the gain will be worth it enough.
Speaking of temperature. I need to have my current very-special-electrical turn off when air temperature is lower than 20F (6.7C), and I had an uncheap waterproof snap-disc, but the only one I could find snapped at 14F, too low. So more recently I found the below. This is one of a series of unusual standard widgets I've been seeing, with consistent part number (XH-W3001) across many manufacturers, many of them unnamed or close. Google that part number, it gets interesting, very new-school. Anyway, its only downside is it registers only in Centigrade! Working range -50°C to 110°C!!! Very nice electronic temperature switch, can be set to switch on the down or the up, throughout that nice range. The 12V version is doing just dandy for me, and much less expensive than the snap-disc. It was very interesting watching the temperature inside my air filter compartment slowly drop while idling. I do wonder how low it goes, on the highway. The manual says it's waterproof, obviously we'll know more about durability in nine months!!!


Similar threads

Please watch this on my YouTube channel & Subscribe.