I'm pretty new to this whole ordeal of modifying my car (a 85' GSL-SE). I have slowly tinkered with it over the past year and now that it runs pretty good I felt its time to upgrade some stuff. I was wondering what most people do with the 13b's air intakes. Do most people usually leave in the box air filter system or do you pull it all out and put in a more direct intake with like a cone filter? Also how much work does it take to make this conversion to a more direct system? Is it just pulling out the old stuff and putting on the new tube and filter or is there a lot more to it? As I said I'm a newbie, so any help you can give me would be great.

 

I spent like 60 bucks or less on my air intake for my car. I relocated a K&N cone filter form where the box is to in front of the radiator. Seems to work pretty good, and its out of the hot engine bay. If youd like more info i can find a link to a how to i wrote

 

yeah any help would be great thanks

 

here is my writeup from many moons ago on the Bonez cone intake, would be about the same for any cone intake upgrade

http://rx-7.org/1stgen/intake.htm

 

The only problem ive found with max7's way is that it leaves the inatek inside the hot engine bay. My way is slightly more expensive, requires a little more work, but your intake is getting fresher air.

http://s4.invisionfree.com/RotaryBlv...?showtopic=117

 

A real big problem with moving the air intake tube out from the engine compartment is the risk for sucking in water. The rain/puddle water will not compress if pull into your motor and will destroy your engine. Great for dry weather, but raining season, I would keep my air intake in the engine bay.

John

 

Step 2 -

Making a cold air box for your new cone filter

http://max7.rx-7.org/cold_air_box.htm


even in a HEAVY down pour I have had zero problems in the rain with this setup.

 

i would not think it would be too common for water to get into the engine through the filter, even in a rain. i would worry in a downpour though. i am glad you had no problems with your filter sucking water!

 

The filter is in front of the tires, and up pretty high, theres next to no way for the water to get into the filter. the little that probably does just steam cleans the beast

 

GSL-SE hood + 280z turbo hood vent + saw + fiberglass = my Quasi-Ram-Air system

 

i really like that set up where'd u get that sheet metal from? and is there a cover to go ontop of that so the air doesnt escaped and is concentrated in that one path?

 

I work at a metal fab shop

I was thinkin of building a top, but figured the engine could take as much as it wanted and the rest could spill over to cool the engine bay a bit. the bottom is also somewhat open.

 

Your workmanship looks great. However, the box looks like it's walls are very close to the intake cone. This is not good for airflow or intake volume. It also looks like the hole you've got for the cold air intake is pretty small, again, not good for airflow. The point of the big cone filter is to suck in more air, but it can't be as effective if there are walls around it.

I'd suggest making the cold air box much larger so that the walls are far from the cone and open up that intake hole. Also, I'd take off the grill from the hole, it's just hurting airflow. Or you could keep the box the way it is and replace the cone filter with a mushroom head style. Either way, you want to open up the cold-air hole some more. If the cold air hole is large enough, you won't have to worry about closing off the top and bottom of the box.

My guess is that the way the box is now, you're still probably pulling most of your air from the engine bay.

 

Ever seen the intake tube? its smaller than the opening in front which is about 3x the afm opening. The mesh is there to keep out debris, leaves, furry animals, hehe.

the box goes from the radiator to inner fender well, I can't see moving either of these items. the filter also has a filter element in the front. and there is alot of open area on top and bottom. yes the sides are a bit close but then again I would of had to find a way to create more space that wouldn't be needed anyways.

It gets plenty of cold air, on a hot day you can open the hood after hours of beating on it, and the inside of the box and filter is still cool, years ago when I had it in my other GSL-SE I drove it a bit in the winter and had to cover the opening up as the air was TOO cold, my A/F meter never read rich.

After having this for 4 years, it works well. but its getting ripped out when I lay my radiator over. so I will be working on a new box.

 

www.mariahmotorsports.com has a cold airbox for the second gen. But i've heard it will fit a first gen with a little modification.

 

There are less frictional losses in your intake flow if you can move air through the largest openings possible. This is why you want the opening into the box to be absolutely as large as it can be. With the box open at the top and bottom, I wonder if you need the screen.

The pressure just inside of the inside of the cone wants to be uniform, if the spacing outside of the cone isn't uniform you'll have low pressure zones in the restricted spaces, reducing your total potential inlet volume.

The inside of the box being cool is a good sign, but it may not be telling you where the majority of the intake air is actually coming from. The best way to tell would be to tap into the intake air temp sensor. The a/f mixture sounds like an intake air temp sensing issue as well as the computer should be compensating for air density changes.

I'm just suggesting some potential improvements, not trying to critisize at all. Someone building a new box might want to start with your design and make improvements recommended by an engineer with experience in airflow.

 

Unless you drive the car into a pond deep enough to submerge the intake or the cold air box is designed in a way that water will collect and puddle, this will never be a problem.

 

Nice try but too much effort and hardly as effective as the cold air intake i put together for 2 dollars.

 

$2? have any pictures or a bit more info?

 

Heres my el-cheapo cut open stock airbox with cool air funneled in from the front via ducting... cost a little over 2 bucks to do

 

Everybody has their own method; for mine, I chose the Mariah NACA ducted headlight lid and routed this internal air passage to a modified air tube leading into the stock airbox inlet position. K&N filter added, and you can feel the suction from the NACA duct when you rap it up. Plus, when you look up the duct, you can see the top of the filter element - showing that this is the straightest and shortest path to get cooler air from outside the car to your intake:

In this picture, you can't see the NACA duct very well, but you can see the airpath to the airbox:



Here's Mariah's picture of the NACA duct that I used:

 

do not put your intake infront of your radiator. that is stupid and possibly very bad for your engine. first it is bad because you increase the possibility of sucking water into your engine. second you want the air moving into your engine as fast as possible. if you put the filter further away from the afm the slower the air will reach it because the air will slow after passing through the filter. solution, make a way to get colder fresh air from outside to your cone filter attached to the afm. everyone has a different way to do this. do some research and find a way that you want yours to look.

 

I'd disagree on some level with everything said here.

 

care to explain

 

You'll ALWAYS get moisture in the intake. A little water in the intake isn't going to hurt anything. Some people have actually been pouring it down their carbs to clean the engine. Of course you can hydrolock the engine, but unless the intake is entirely submerged, it's not going to happen.

Airflow resistance is related to airspeed. Airspeed will be fairly consistant all the way along a set diameter tube like the intake tube on an SE so no matter where the AFM is along that tube, the air resistance will always be about the same. The shorter the tube, the lower the overall flow resistance, but within the a tube like this, there won't be much difference in speed along the way.