2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Stock Air box Mod for FC ( Weekend Project)

Thread Tools
 
Search this Thread
 
Old 05-09-10, 07:10 AM
  #1  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
Stock Air box Mod for FC ( Weekend Project)

One day I thought to myself why does the stock air box have these square like structures in the air box on my 90 N/A FC?



So I thought maybe I could grind them down and get more smoother air coming down into the MAF. So I began the process of this.





Eventually I got to this but I'll need a small rotary tool with a wirer or grinder attactment to get to those hard to reach places for that though. I did sand down the high spots with 150 grit sandpaper. And maybe some 350 - 400 grit later.



I have notice the throttle is a bit more responsive after 2k - 7k rpm.
I still do want to grind out the top part of the stock air box for less resistance in air flow. Free-ier flowing air box mod? What you ya'll think?
Old 05-09-10, 07:31 AM
  #2  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
those little structures there are probably to reduce noise
Old 05-09-10, 10:16 AM
  #3  
Love Thy Rotor

 
2ndgencab's Avatar
 
Join Date: Nov 2006
Location: Yuba City, Ca
Posts: 93
Likes: 0
Received 0 Likes on 0 Posts
Very interesting! I like!
Old 05-09-10, 01:01 PM
  #4  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
Originally Posted by arghx
those little structures there are probably to reduce noise
Could be but doesn't the intake snokel have a silencer on it and a small hole at the begining of the snokel?
Old 05-09-10, 01:08 PM
  #5  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
That gridwork is very standard reinforcing for plastic stamped parts.
There is no way that grinding it away made any difference whatsoever to airflow through the box or throttle response.
Old 05-09-10, 01:16 PM
  #6  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
I can tell you it feels slightly different than before. I have 2 stock box so I can always swap back if needed.
Old 05-09-10, 02:08 PM
  #7  
My job is to blow **** up

iTrader: (8)
 
lastphaseofthis's Avatar
 
Join Date: Jan 2005
Location: palmyra Indiana
Posts: 2,900
Received 3 Likes on 3 Posts
i'll give you a stock airbox and let you get back to back dyno's stock and your 'modified' box. it would shut these guys up and let you prove your 'improved throttle responce'. i really don't see any harm in doing this. if the box was to break, they're easy to find.
Old 05-09-10, 02:15 PM
  #8  
Death or Glory

iTrader: (16)
 
The CzAR's Avatar
 
Join Date: Dec 2003
Location: Phoenix
Posts: 398
Likes: 0
Received 1 Like on 1 Post
Originally Posted by rotary#10
I can tell you it feels slightly different than before. I have 2 stock box so I can always swap back if needed.
The placebo effect.
Old 05-09-10, 03:27 PM
  #9  
The Doctor

iTrader: (1)
 
g14novak's Avatar
 
Join Date: Apr 2008
Location: Cedar Rapids, IA
Posts: 1,185
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by The CzAR
The placebo effect.
Butt dyno effect.
Old 05-09-10, 04:17 PM
  #10  
Rotary Freak

iTrader: (3)
 
funkjaw's Avatar
 
Join Date: Jul 2008
Location: San Jose, CA (NorCal/S.F. Bay Area)
Posts: 2,515
Received 4 Likes on 3 Posts
***** effect.


I mean very interesting. Maybe find someway to test the airflow capabilities of your modified box compared to a stock box?
Old 05-09-10, 04:48 PM
  #11  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by funkjaw
Maybe find someway to test the airflow capabilities of your modified box compared to a stock box?
Irrelevant.
Measure airflow through the throttle body instead, that would be useful.

It's possible that "porting" the airbox increases flow- almost certainly of the "measurable" instead of "discernible" variety but for the sake of discussion I'll concede it- but you then run it through the stock MAF and the intake elbow, both of which are bigger restrictions than the airbox could ever be.
Net gain at the throttle plates...zero.

Even granting a measurable increase in CFM- and I think I'm being very generous doing so- it could not be significant enough to result in a gain big enough to feel.

Sorry but I still call shenanigans.
Old 05-09-10, 04:50 PM
  #12  
On the fasttrack!

iTrader: (22)
 
magus2222's Avatar
 
Join Date: Oct 2006
Location: virginia beach, virginia
Posts: 2,493
Likes: 0
Received 0 Likes on 0 Posts
lol, i just told him it was probably a waste of time, but oh well, i did alot of that stuff when i first started on cars too. i didnt know the difference.
hes a great guy, local to me. hes smart, he gets it, some things are just for fun

Lloyd
Old 05-09-10, 05:00 PM
  #13  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by magus2222
lol, i just told him it was probably a waste of time, but oh well, i did alot of that stuff when i first started on cars too. i didnt know the difference.
hes a great guy, local to me. hes smart, he gets it, some things are just for fun

Lloyd
Fair enough.
Old 05-09-10, 06:22 PM
  #14  
Slowpoke

iTrader: (3)
 
Hypertek's Avatar
 
Join Date: Jun 2006
Location: Socal
Posts: 5,273
Likes: 0
Received 6 Likes on 6 Posts
throw in a aftermarket air filter in there and mod the throttle body while your at it.
Old 05-09-10, 08:39 PM
  #15  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
I have a K&N drop in. TB mod is possibly next.
Old 05-09-10, 08:50 PM
  #16  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
Originally Posted by magus2222
lol, i just told him it was probably a waste of time, but oh well, i did alot of that stuff when i first started on cars too. i didnt know the difference.
hes a great guy, local to me. hes smart, he gets it, some things are just for fun

Lloyd
LOL then thats what its for then. I'll finish grinding out the box and top next weekend and have some others locals drive my fc and see that they say.

How would I could test for airflow?
Old 05-09-10, 09:07 PM
  #17  
oi oi oi

iTrader: (7)
 
john ward's Avatar
 
Join Date: Jan 2006
Location: wilmot,oh
Posts: 611
Likes: 0
Received 1 Like on 1 Post
Sorry but there so many restrictions after its doing nothing
Old 05-09-10, 10:54 PM
  #18  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
Originally Posted by rotary#10

How would I could test for airflow?
You'd need a flowbench.
Basically, there is no simple way to document your results.
An instrumented flowbench could show how it worked or some dyno time would provide even more relevant data.

Best of all would be to have two FCs at the dyno and swap the airbox cover between the pair.

It looks like you did a very nice job removing the webbing, I just think your enthusiasm and effort could be better rewarded in other areas.
Another thing to keep in mind...
These cars are now 20 years old and lots of smart people have molested them.
If something as simple as grinding the airbox cover really worked, don't you think we'd all know about it by now?
Old 05-10-10, 02:17 AM
  #19  
Vodak

Thread Starter
iTrader: (38)
 
rotary#10's Avatar
 
Join Date: Aug 2005
Location: Oakland, CALI = O
Posts: 881
Received 44 Likes on 31 Posts
Originally Posted by clokker
You'd need a flowbench.
Basically, there is no simple way to document your results.
An instrumented flowbench could show how it worked or some dyno time would provide even more relevant data.

Best of all would be to have two FCs at the dyno and swap the airbox cover between the pair.

It looks like you did a very nice job removing the webbing, I just think your enthusiasm and effort could be better rewarded in other areas.
Another thing to keep in mind...
These cars are now 20 years old and lots of smart people have molested them.
If something as simple as grinding the airbox cover really worked, don't you think we'd all know about it by now?
Well its off to the dyno after I mod finish modding the box. Well time to get to the body work then.
Old 05-10-10, 03:58 AM
  #20  
On the fasttrack!

iTrader: (22)
 
magus2222's Avatar
 
Join Date: Oct 2006
Location: virginia beach, virginia
Posts: 2,493
Likes: 0
Received 0 Likes on 0 Posts
its about damned time, sick of looking at that oreo you call a car :P

Lloyd
Old 05-11-10, 02:01 PM
  #21  
Rotary Freak

iTrader: (3)
 
funkjaw's Avatar
 
Join Date: Jul 2008
Location: San Jose, CA (NorCal/S.F. Bay Area)
Posts: 2,515
Received 4 Likes on 3 Posts
Let me know when the next dyno day is I'll go out there with ya.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
astrum
2nd Generation Specific (1986-1992)
24
11-15-17 08:44 AM
JIMMY54
1st Generation Specific (1979-1985)
2
08-12-15 05:40 PM



Quick Reply: Stock Air box Mod for FC ( Weekend Project)



All times are GMT -5. The time now is 07:29 AM.