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malder

Cold Air Induction

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Has anyone fabricated any sort of cold air induction system for an early Z?

I was thinking about this the other day and wondering whether that might be a source of some easy power... how much I don't know, but it couldn't hurt, right?

If you could just have a K&N cone filter mounted on some tubing that mounted to the carbs with the tubing out in front of the car.... it's done all the time on newer cars, right?

anyone done this? Thought about it?

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Since this site is predominantly populated by carburated Z's (although some recent polls show that is changing...) the subject of 'Cold Air intakes' doesn't come up too often--especially home-made ones. On the 'Brand X' forum (the one with all the punks) it comes up constantly. About once a week, some loser will trot out photos of his PVC/ABS/ADS/CPVC/Dryer Duct/3" truck exhaust pipe cold air intake he somehow tek-screwed, zip-tied, or duct-taped to his car. Of course they are all topped off with the requisite K&N. It is possible to make your own. It is possible to make one and have it look good. The latter just doesn't happen very often.

steve

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What Steve(zvoiture) is saying, is in a nutshell yes you can do it but to be completely honest they look messy and they really don't do anything.

If your using a stock intake and carbs say SU's. Then the airbox points so close to the front of the engine bay that it's practically perfect how it is.

If you have a 280zx or 280z with FI which i don't think you do with a L26 in there then you can use what other steven has shown.

There are other pods you can put on the front of the SU's but honestly they just soak up the heat from the exhaust manifold.

:classic:

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From the pictures I've seen, it looks more like the intake for the carbs are getting more hot air from the radiator than the exhaust, depeding on your speed.

In that case, all you wouls need is a snorkel to get air fropm behind the headlight.

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That's what I am getting at. The idea is to get the air from as far foreward as possible. Right?

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I started a thread over at HybridZ on this, claiming that a "cold air intake" was a total crock, based on the thing that I saw the ricers doing.

What I saw was this long pipe reaching over the top of the engine, then down a little to a corner next to the radiator( or behind it) to where the filter cone was. To me all this means is that you got a nice long pipe picking up the heat from the top of the engine, and from behind the radiator. Cold? NO. Fresh, yes, but not cxold. You're better off with a regular car off the street; at least they are getting the air from inside the fender, where it's slightly protected from splashing water, and definitely as cold as the air on the outside of the fender.

Otherwise, it looks like a snorkel hood, or a cold air box directly under the hood with an NACA scoop, or some kind of ram-air setup is really going to get you fresh, COLD air. Even those simple cold air things for the fuel-injected Zeds is much better, especially if you still use the stock air filter box with the tube that goes across to the other side.

If you think of it, those long, chrome "cold air" pipes the ricers use might look nice (to them), but that's about all it does.

Just another useless thing marketing people do to get you to buy stuff.

(my favorite use less thing besides cold air intakes is the tornado air spinner.

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could also look into cowl induction. Not sure if there is room though. and im not familiar with carbed engine bay

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Howdy,

I am sure a good cold air induction system would help a little. I think it is somewhat of a scam with how heavily they are marketed these days. But for a track or race car I am sure they help a bit.

Scott B., former owner of Ztherapy, used to make a custom airhorns and a airbox for the 240Z SU style carbs. But it wasn't cheap, something like $400. It looked good with about a 3" round inlet so you could easily plum to the front. I think he opened up one of the holes in the radiator support and ran a cone type filter like K & N.

I have also seen someone show a picture on the web of a design that used the 280Z hod vents as an inlet. They sealed the front of a 240Z aircleaner, cut an oval opening in the top of the aircleaner, attached oval rubber to it to form a seal to the closed hood. Here the problem would be with rain getting in there.

The 280Z's have cold air intake stock with the air cleaner in front of the radiator housing.

Have fun!

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Maulder,

Good question.

It is first necessary to understnd the difference between "cold air" iduction and "ram air" induction.

Cold air iduction is not ram air induction, BUT ram air induction IS cold air induction.

Ram air induction only works when the inlet (cold, fresh air) pressure is higher than the oulet (air sucking, fire-breathing engine) pressure.

Ram air is a prinicple that scientificly works! After all, what do turbos and superchargers do?

The ram air effect increases with road speed, BUT decreases with engine RPM. The faster the car moves the more air RAMMED into the engine, but the faster the engine turns the MORE AIR IT REQUIRES (increased outlet pressure) for a net pressure drop from inlet to outlet.

I was once at a freiends race shop (he now designs for John Caldwell Engines) while they dyno'ed a formula super-vee 1600 cc race engine. It was necessary to open the front door of the shop while making a dyno run. If they didn't, after 5 minutes the engine stalled from sucking all the air from a 8,000 square foot shop (the exhaust went into a refridgerator, used as a muffler, outside)

I don't want to give away all my ideas, but if you are interested (and are not affraid to spend money!) I have plans for a cold/ram air set-up for SU and Mikuni Z cars. I'm not going to get to it until fall or next winter though. It deffinately won't look cheesy.

Pancho

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Originally posted by panchovisa

I was once at a freiends race shop (he now designs for John Caldwell Engines) while they dyno'ed a formula super-vee 1600 cc race engine. It was necessary to open the front door of the shop while making a dyno run. If they didn't, after 5 minutes the engine stalled from sucking all the air from a 8,000 square foot shop Pancho

And everyone passed out ROFL ROFL ROFL

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owenk,

A 2.4liter Z engine is 158 cubic inches.

At 7,000 RPM it fills that volume every four revs (4 cycle engine), or 1750 times.

In five minutes thats 8,750 times, or 1,386,000 cubic inches(802 CUBIC FEET).

MY friend(crew chief of Lemans 24 hours winner, 26 national SCCA championships, IMSA GTU champion, collector of royalities from Ford, Mazda & Lotus, and alround brilliant race mechanic) says that was enough (ok, 10 minutes) to lean out a fully trick engine enough to stall.

I didn't see it happen, I just belive the numbers.

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To be honest I thought of exactly the same thing , I am not saying your full of crap or anything I believe it I just thought it was funny also :).

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I've seen this happen when running uninstalled air craft engines. It happens a lot quicker and the air does get noticeably thinner.

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