So n my `84 GS I took off that little black tue that hangs off the Air Filter housing about 8" Right on the inside of that opening there is a flap that opens and closes. It has some sort of lever that opens it running down to the carb or something. What would happen if I removed this flap? It looks like a major air restriction. Would it be bad to take it out? I have heard you can get more air into the engine by cutting holes in the lid that goes over the air filter. Anyone else heard of this? Anyone done this?

 

most folks take em out,,,,just remember that the stock carb is made to handle just so much air, too much air will not improve performance is my opinion....

 

what will happen if the carb gets too much air? will it not burn rich enough?

 

thats getting into physics, i am not the one to answer, but more air with more gas goes hand in hand,,, the stock nikki will only go so far with its cfm...but the jets can be enlarged to handle both more air and gas,,,,

 

that flap is part of the heat riser system. there is a tube that comes from the heat shield and a coil inside of the air cleaner assy. as heat from the exhaust comes up, the flap gradually closes based on heat contracing the coil and heats up the carburator. once the carb and engine is heated, the flap is closed.

 

The REAL reason for that flap is temperature regulation!

You can run a stock nikki without an air cleaner assembly at all! It won't get "too much air" because the air it takes in is based on vacuum suction from the engine. Therefore if you had no restriction at all it would take what it needed and leave the rest. That's why carbs run better without the cap on... However if you did that the air wouldn't get cleaned.

If you look carefully, you'll see that the flap actually opens and closes an opening on the bottom of the snorkel. If your car is still in good enough shape, that opening is connected to a hose, which is connected to a heat shield surrounding the exhaust manifold. I'm not sure if it defaults to open then closes, or starts closed then opens, but it's designed to mix warm air from the exhaust manifold with cold air coming in the snorkel to change the temperature.

What this means is that people who install "cold air intake" systems but leave this flap/hose/heatshild combo intact are actually doing nothing to their car except adding weight.

I'm not sure exactly WHY mazda put this system in place. Cold air is denser, and thus a cold air/fuel mix has more air/fuel and produces more power. That's why cold air kits are so readily available for most cars. Why they would need to warm up the air, I'm not sure. I just know that they do.

Jon

 

mazdaverx713b beat me to it dang.

 

man .. you ask a simple question and you get the real answer , everytime , i swear .. no b.s. on this forum , just facts , i like that the info is from knowledge as opposed to hearsay .. cheers

 

lol, it doesn't matter, you still provided a great explanation, lol.