Jump to content
Ultimate Subaru Message Board

MAF Adapter


Recommended Posts

So now that i've got the smog finally done and the Hatch is running great, i would like to add a little more, get up and go! You know, power. For being a EA81 with Spfi its pretty fun already, but a little bit more would be bad rump roast. So i was thinking of adding a cone air filter with a maf adapter but im having trouble figuring out exactly which one is the right one. Any Input or sites i can check out. Was also thinking about picking up a GL-10 muffler to get rid of some of the restriction.

Link to comment
Share on other sites

the stock air filter flows ample air for a 1.8L four cylinder. The stock replacement filter for the EA SPFI was the same cartridge used for an NA first gen 300ZX, 170 hp 3.0L V6. If it can flow that much air, it can flow enough for the little boxer.

 

The limitations on airflow lie in the intake port sizes in the head (shared between two cylinders each) and the sheer size of the manifold and throttle body. You can inspect the matchup of the TB to the manifold, as well as the matchup of the components of the throttle body itself, and make sure all airflow surfaces and transitions are as clean as possible, and if you want to get into it take the manifold off and port match it to the head... and gain probably a little smoothness, a little power, and a little efficiency at all RPMs, but the gain would barely be noticeable. Its sort of an anal-retentive thing.

Link to comment
Share on other sites

i doubt that you would find any gains with another muffler from a gl-10. if im not mistaken, they used the same muffler between all the car, turbo or not. you would be better off with an aftermarket muffler if you are looking for any kind of power gain, but there is only so much one can gain from exhaust in a non turbo car.

Link to comment
Share on other sites

i doubt that you would find any gains with another muffler from a gl-10. if im not mistaken, they used the same muffler between all the car, turbo or not. you would be better off with an aftermarket muffler if you are looking for any kind of power gain, but there is only so much one can gain from exhaust in a non turbo car.

 

Well i read somewhere that the EA81 muffler is very restrictive, and that the turbo models muffler was alot less restrictive. And opening up the exhaust would give a bit more low end torque. And i would go aftermarket but i dont want the loud, ricer sound of most mufflers.

Link to comment
Share on other sites

the stock air filter flows ample air for a 1.8L four cylinder. The stock replacement filter for the EA SPFI was the same cartridge used for an NA first gen 300ZX, 170 hp 3.0L V6. If it can flow that much air, it can flow enough for the little boxer.

 

The limitations on airflow lie in the intake port sizes in the head (shared between two cylinders each) and the sheer size of the manifold and throttle body. You can inspect the matchup of the TB to the manifold, as well as the matchup of the components of the throttle body itself, and make sure all airflow surfaces and transitions are as clean as possible, and if you want to get into it take the manifold off and port match it to the head... and gain probably a little smoothness, a little power, and a little efficiency at all RPMs, but the gain would barely be noticeable. Its sort of an anal-retentive thing.

 

I understand that the airflow through the stock filter is more than enough for the motor. But its not the filter itself that im concerned with, its the air intake opening in the side of the airbox. The whole is maybe 3" long and 1 1/2" wide. Pretty small in my opinion. I figured opening up the exhaust and intake would help improve performance. And making the whole bigger is not an option since i do have to smog this car and i am in california. And i cant seem to find the same airbox in the junkyard.

Link to comment
Share on other sites

Well i read somewhere that the EA81 muffler is very restrictive, and that the turbo models muffler was alot less restrictive

Turbo mufflers are the exact same mufflers as non-turbo ones. Even same part numbers.

 

You're probably thinking of generic "Turbo" mufflers. They're regular mufflers that are designed to be less restrictive.

Link to comment
Share on other sites

Turbo mufflers are the exact same mufflers as non-turbo ones. Even same part numbers.

 

You're probably thinking of generic "Turbo" mufflers. They're regular mufflers that are designed to be less restrictive.

 

OK, so where can i find these "turbo" mufflers. I dont want loud. Maybe a little tone but thats about it.

Link to comment
Share on other sites

Dynomax super turbo muffler. Thats what i have on my sedan. Nice and quiet but with a little growl when you get on it. Flows very nice. As for more power you already got the SPFI swap. How is the rest of your exhaust? Do you need to do emissions? If not...dump the catalitic converter and straight pipe it or if you dont like that idea just get a generic high flow cat.

Link to comment
Share on other sites

Dynomax super turbo muffler. Thats what i have on my sedan. Nice and quiet but with a little growl when you get on it. Flows very nice. As for more power you already got the SPFI swap. How is the rest of your exhaust? Do you need to do emissions? If not...dump the catalitic converter and straight pipe it or if you dont like that idea just get a generic high flow cat.

 

Cool, ill check it out. Is there a specific size or part #?

Link to comment
Share on other sites

The whole is maybe 3" long and 1 1/2" wide. Pretty small in my opinion. I figured opening up the exhaust and intake would help improve performance. And making the whole bigger is not an option since i do have to smog this car and i am in california.

 

How small is the hole that's bringing air into the filter box itself? I know on EA82's it's extremely small and making an additional hole helps with performance slightly. Or at least I've been told... I didn't really notice any difference.

Link to comment
Share on other sites

How small is the hole that's bringing air into the filter box itself? I know on EA82's it's extremely small and making an additional hole helps with performance slightly. Or at least I've been told... I didn't really notice any difference.

 

3" x 1 1/2" or so, i got the SPFI from a EA82 Loyale. But i dont want to cut a hole in the airbox because i do have to smog the car in california. If i could find a replacement lower portion of the airbox that would be cool, but since the MAF adapter and cone element cost only about 25 bucks i figured if would be easier and would allow more air then just cutting a hole. And i could just swap out the airbox when smog comes around every 2 years.

Link to comment
Share on other sites

The correct MAF adaptor is for a Nissan 200SX. I used one just because trying to fit the damn EA82 airbox in an EA81 bay is problematic.

 

GD

 

200SX, thats all i needed to know. Thanks! And the airbox fit no problem in my Hatch, i just want a little more now that i finally passed smog. Also looking into getting muffler.

Link to comment
Share on other sites

200SX, thats all i needed to know. Thanks! And the airbox fit no problem in my Hatch, i just want a little more now that i finally passed smog. Also looking into getting muffler.

sorry to dicker, just wanted to make it clear. If I'd have known the answer, I would have told you.

Link to comment
Share on other sites

So, i ordered the MAF adapter from ebay for the nissan and it was finally delivered today. I went down and bought a cone air filter from the auto parts store and put it all together. And Holy Crap, wouldn't you know it, it actually made a noticeable difference over the stock airbox. Some people said its not going to make a bit of difference, but a snappier throttle and a definate increase in low end torque makes me a believer. Cant wait to swap out the muffler next week.

Link to comment
Share on other sites

The correct MAF adaptor is for a Nissan 200SX. I used one just because trying to fit the damn EA82 airbox in an EA81 bay is problematic.

 

GD

So what did you do to mount the cone filter? Mine saggs and flexes the whole intake tube down til the filter touches the wheel well.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...