Size of Cone Air Filter: Small vs. Large Any Flow Difference?
#1
Full Member
Thread Starter
Join Date: Mar 2001
Location: Middlebury, Indiana, USA
Posts: 122
Likes: 0
Received 1 Like
on
1 Post
Size of Cone Air Filter: Small vs. Large Any Flow Difference?
Hey all,
I just bought a K&N air filter from a guy, but did not realize that it was the small one (~4-5" tall). Would it be acceptable to use this, or would it create a bottleneck? I'm just not sure if the air flow would be higher than that of the afm. Should I just buy that larger filter? Suggestions appreciated.
I just bought a K&N air filter from a guy, but did not realize that it was the small one (~4-5" tall). Would it be acceptable to use this, or would it create a bottleneck? I'm just not sure if the air flow would be higher than that of the afm. Should I just buy that larger filter? Suggestions appreciated.
#5
Former Rx7 *****
Join Date: Nov 2001
Location: Mississauga
Posts: 4,534
Likes: 0
Received 0 Likes
on
0 Posts
bigger means more HP but to a certain extent. remember the intake hose (the piping to the engine) has a cross section diameter of X amount and that determines the amount of volume of air that it can flow through at a given time.
#6
Rotorhead
Join Date: Feb 2001
Location: Charlottesville, Virginia, USA
Posts: 9,136
Likes: 0
Received 39 Likes
on
33 Posts
That size should be good for 200-275bhp, depending on whether it's closer to 4 or 5" in length. Unless it is actually causing a noticeable restriction, the smaller filter is fine, and the only advantage in a larger filter would be that it filters more air which increases the service life of the filter. If it is causing a noticeable restriction, then you will need a longer filter.
#7
Lives on the Forum
I use to run a smallish air filter - K&N universal PN-RU3120 which was like 6" tall, 4" diameter bottom, 2" diameter top, taper, 10-degree offset.  Yes, it was a dinky filter.  With no boost control, my turbo would barely hit 9psi.  I swapped it out for those typical "Funnel II" (R.S. Akimoto rip-off) type air filters, and my boost immediately hit 12psi.
-Ted
-Ted
Thread
Thread Starter
Forum
Replies
Last Post
Frisky Arab
2nd Generation Specific (1986-1992)
13
08-18-15 05:30 PM
KAL797
Test Area 51
0
08-11-15 03:47 PM