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Discussion Starter #1
I've been meaning to install a cold air induction pipe for a while.

While the Z33's induction is better than most (the intake draws air from in front of the radiator and outside the engine bay proper) I figured it would always come in handy to have a pipe duct air from the outside world straight in there.

Rather than spend several hundred dollars picking up a K&N Typhoon kit (which would have cost double what the Popcharger did) I just went down to the hardware store and made my own.

Anyway: here are the results:

http://my350zis.fucken.1337.as/gallery/my350z_cai

I've removed a plastic baffle from the bumper (which doesn't seem to serve any purpose as it doesn't protect anything) and run a length of PVC pipe up there, between the plastic surround and the intrusion beam support, and into the intake snorkel.

To protect the ducting, and hopefully my filter, I've also flyscreened the opening.

I took the car for a quick run last night on my favourite stretch of windy road, and while I can't feel any difference in power its at least nice to feel that the metal surround on the Popcharger was still cold to the touch. I'll have to test it in day to day driving, when its most likely to draw hot air in and the filter ring does get hot to the touch.

Since, all up, the bits and pieces cost me less than $10 its cheaper than buying a custom-made system. At that price, I've hardly lost a lot of money on something that doesn't bring an appreciable power gain (but will hopefully assist the engine).
 

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Looks ok.
The only thing to watch out for is maybe at high speeds the flexible ducting might push onto itself and restrict some of the airflow into the engine compartment. I mean the area around the bottom of the bumper.
Just watch out that it doesn't do that because then the area where the air gets into the engine area will be blocked or airflow reduced and you will be sucking in hot air from the engine.
I don't know if that made sense.
A+ for effort anyway!
 

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Did you notice that it moved around after your drive? Do you think there is enough room for the tubing to be directed to the brakes?
 

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Scathing - I'm not so sure that is a good mod.

Essentially, the factory intake draws air from the entire open are in the bumper, even if it has just a small opening to get through to the filter. What you have done if to decrease the surface area through which fresh air can be collected to a 12cm diameter opening.

This is just my opinion - just like an arsehole, everyone's got one.
 

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Originally posted by blacktrack350@Dec 21 2004, 09:13 AM
sorry off topic but what pop charger is that?

Looks like the JWT pop charger.

I agree with ky about restricting air flow. I think an 'airguide' is better suited to control the flow of air into the 'corner' where the intake is situated.
 

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Leave it stock i say!

If you want more air get twin turbos!
 

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Discussion Starter #9
I didn't notice any movement after my drive. Its held in at the bottom with 2 clips in the factory location, and a cable tie onto the grill. Its pretty secure.

The tubing is way too big for my purposes. In hindsight, 80mm tubing would have been far better than 100mm. You could use it for brake ducting, assuming you can find somewhere to put it.
 

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Discussion Starter #10
Originally posted by KY350@Dec 21 2004, 05:58 AM
Essentially, the factory intake draws air from the entire open are in the bumper, even if it has just a small opening to get through to the filter.  What you have done if to decrease the surface area through which fresh air can be collected to a 12cm diameter opening.

That would be true if the intake snorkel was drawing air from the entire grille.

But, don't forget, that the factory intake snorkel just opens up to the front bumper, and the bonnet is rubber sealed so very little direct air travels into it. While not drawing air from the engine bay proper, its still drawing relatively "still" air that's been in the car for a while.

There's also a plastic shroud from the front grille to the radiator, which means to get to the intake the only 2 paths are through the hole around the bonnet latch, and then the narrow path across that plastic shrould, and the small gap between the support and the front intrusion bar.

My flex pipe's diameter is bigger than the latter gap, so for that path (which is the most direct and the largest) the only loss in surface area is the thickness of my PVC pipe (which is millimetres).

With hydrodyamics, the air will follow the path of least resistance which means most of it will pass through the radiator. It can only flow as quickly as through the narrowest section of the path, which means I'm not losing that much flow.

On the positive side, my flex pipe does theoretically acts as a ram-air pipe. It is right in the meat of the airflow and ducts air into the snorkel, as opposed to the factory setup that has air flowing into the grille (and not the entire width with those plastic baffles, so the point in the grille closest to the air intake is actually blocked). This air then hits the radiator, deflecting up and eventually finding its way through that aforementioned gap into the intake snorkel.

While I may lose a few millimetres in surface area through with that pipework, what I gain is ram-air induction. Instead of drawing air that has lost most of its force and potentially heated up, I'm ducting air that's directly in the airstream and directing it to the filter with close to the full force of whatever speed I'm travelling at. While there are bends in the pipework and it is ribbed, which will cause turbulance, there's nowhere for the air to go and the path is a lot more direct than the stock setup. Given that, it is possible that it delivers more air.


Ideally, I would have made the induction pipe shorter and stretched the pipe out as much as possible to reduce turbulance in the pipe. I'd also have bought 80mm pipe as the 100mm is still too wide in some spots, and if I had the time to remove the front bumper I would not have ducted it all the way to the intake snorkel. I would have just had it poking up in the bumper.

While that Varis air-guide would be a far better solution (and I'd love to get one eventually) this one cost me $10 and a few minutes of work. The gains are not very appreciable (I get the feeling my car's induction sound is a few notes deeper) so if I have hassles with it, I'll take it out.
 

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Scathing - you're right about the ram air effect.

Yes the Varis solution is a nice one, but in reality, I would think that the increase in HP would be minimal, even with this mod.
 

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Discussion Starter #12
There's almost no gain from what I can feel. Same as with my Popcharger.

If it works properly, though, it means I'm drawing colder air so I'm hoping it'll help the engine's longevity and improve throttle response.

There's not much to be made with a N/A car when it comes to induction mods.
 
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