Older bmw 3 series from the eighties have a adapter plate on their intake box that fits right on a festiva VAF. From there you can use a cone filter.
Alot of people have been using the aspire intake and hacking it off by the valve cover and moding it to fit a festiva. It looks alot cleaner, and getrid of that resonator box that sit on top of the valve cover left of the TB.
You can accomplish much of the same thing for nothing by drilling a bunch of holes in the bottom piece of the airbox. Take it for a drive before the mod, and pay attention to how it accelerates up to 5,500 RPM or so. Then do the mod, drive it again and notice the difference. It will breathe much more freely with all the little holes. I recommend 25 - 30 holes, using a decent size bit like 1/4". Three 10mm bolts hold in the airbox bottom.
Notice the size of the hole coming into the airbox, and the size of the hole going into the VAF meter. There's your sign. Manufacturers make the air-intake hole so small to cut down on noise; there is no other reason to make it this small.
You can also just remove that dopey resonator box and cover the hole suitably.
Any airflow improvement will only matter at higher RPMs, say above 3500 or so.
You can accomplish much of the same thing for nothing by drilling a bunch of holes in the bottom piece of the airbox. Take it for a drive before the mod, and pay attention to how it accelerates up to 5,500 RPM or so. Then do the mod, drive it again and notice the difference. It will breathe much more freely with all the little holes. I recommend 25 - 30 holes, using a decent size bit like 1/4". Three 10mm bolts hold in the airbox bottom.
Notice the size of the hole coming into the airbox, and the size of the hole going into the VAF meter. There's your sign. Manufacturers make the air-intake hole so small to cut down on noise; there is no other reason to make it this small.
You can also just remove that dopey resonator box and cover the hole suitably.
Any airflow improvement will only matter at higher RPMs, say above 3500 or so.
what is that?.... dopey resonator box
1990 Festiva L sport 26.5k miles
snow drifting machine
sunpro supertach II, racing pedals, new deck, air horn
blue neon
It's the little black plastic box that is to the left of the air intake pipe that comes over the center of the valve cover. If you pull it off, you are left with a hole that needs to be covered. I used a plastic bottle cap from a gallon water bottle or something, covered it with folded aluminum foil, and held it all on with the clip that was there before.
90 Festy (Larry)--B6M (Matt D. modified B6 head), header, 5-speed, Capri XR2 front brakes, many other little mods
09 Kia Rondo--a Festy on steroids!
You can avoid reality, but you can't avoid the consequences of avoiding reality--Ayn Rand Disaster preparedness
I did what Wes said, cut down the aspire intake to fit..
-93' L BP swap/e-series, coilovers, RIO front swap, redrilled festy drums, Miata 14" 7 spokes.
-88' Mazda 323 SE, work in progress..
-85' Nissan Sentra 5 spd.
It's called a Helmholtz resonator and it actually has a constructive purpose. It's designed to cancel out standing wave vibrations and oscillations in the intake tract. These vibrations can corrupt MAF signals at low RPM and also create an audible noise. They (standing waves) also play a positive role in the proper "ram" tuning or cylinder filling, much in the same way exhaust waves or pulses are used to scavenge exhaust and help draw the intake mixture into the cylinders. These waves are also why longer intake runners create lower frequency oscillations and benefit low RPM performance and short runners create high frequency waves that benefit high RPM performance. I really don't think removing this resonator will either help or hinder actual performance, other than maybe make it sound louder and possibly effect the VAF readings. The size and shape of the resonator is designed/tuned for a specific frequency. Some cars don't require any and some cars have several, depending on the intake tract design, airflow, etc.....................If you must ask.
I read too many books on engine management and tuning.
Adapting the Aspire intake looks better, for sure, as does using an aftermarket filter. I might put on the Aspire stuff myself just because it looks better. But I think the stock filter flows as much air as the VAF could handle anyway, as long as the filter can access enough air--that's why the stock airbox mod.
If someone did a dyno test of drilling holes in the stock lower airbox piece vs. sticking on an aftermarker cone filter, I bet the numbers would be the same or very close to it. So the aftermarket filter is basically an appearance mod, which is fine too.
90 Festy (Larry)--B6M (Matt D. modified B6 head), header, 5-speed, Capri XR2 front brakes, many other little mods
09 Kia Rondo--a Festy on steroids!
You can avoid reality, but you can't avoid the consequences of avoiding reality--Ayn Rand Disaster preparedness
It's called a Helmholtz resonator and it actually has a constructive purpose. It's designed to cancel out standing wave vibrations and oscillations in the intake tract. These vibrations can corrupt MAF signals at low RPM and also create an audible noise. They (standing waves) also play a positive role in the proper "ram" tuning or cylinder filling, much in the same way exhaust waves or pulses are used to scavenge exhaust and help draw the intake mixture into the cylinders. These waves are also why longer intake runners create lower frequency oscillations and benefit low RPM performance and short runners create high frequency waves that benefit high RPM performance. I really don't think removing this resonator will either help or hinder actual performance, other than maybe make it sound louder and possibly effect the VAF readings. The size and shape of the resonator is designed/tuned for a specific frequency. Some cars don't require any and some cars have several, depending on the intake tract design, airflow, etc.....................If you must ask.
I read too many books on engine management and tuning.
Thanks for the background info. But I hate it on principle, so it's gotta go!
90 Festy (Larry)--B6M (Matt D. modified B6 head), header, 5-speed, Capri XR2 front brakes, many other little mods
09 Kia Rondo--a Festy on steroids!
You can avoid reality, but you can't avoid the consequences of avoiding reality--Ayn Rand Disaster preparedness
But I think the stock filter flows as much air as the VAF could handle anyway, as long as the filter can access enough air--that's why the stock airbox mod.
If someone did a dyno test of drilling holes in the stock lower airbox piece vs. sticking on an aftermarker cone filter, I bet the numbers would be the same or very close to it. So the aftermarket filter is basically an appearance mod, which is fine too.
X2. A K&N filter in the factory box should provide ample air for most of us. What I did was cut out the bottom corner of the factory box. Then I epoxied an old rectangular-to-round air cleaner snorkle adapter that was used to connect the round flexible air tube to the rectangular end of the snorkle. (Don't remember what it was off of....maybe a late '70s or early 80's 4-cylinder Mustang). The 4" diameter round end points directly at the grill opening just to the right of the dipstick tube and just behind the radiator core support. It kinda acts like a "ram air", catching incoming air from the grill. You could go one step further and attach one end of a flexible tube to it and the other end to another adapter located below the bumper. I'll post some pics tomorrow if anyone's interested.
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