Performance Forced induction, intakes, exhausts, torque converters, transmissions, etc.

Building an intake...

Thread Tools
 
Search this Thread
 
Old 08-03-07, 11:46 AM
  #1  
Rock-a-Lex
Lead Lap
Thread Starter
iTrader: (4)
 
Rock-a-Lex's Avatar
 
Join Date: Jan 2007
Location: NY
Posts: 4,519
Received 17 Likes on 16 Posts
Default Building an intake...

When buidling an air intake is the largest filter the best (all things being equal such as manufacturer, type of material used etc.) or not necessarily? I'm torn between buying a new K & N filter (very large; over 8" long by 5" wide) or the Apexi Power Filter (maybe 6" long by 5" wide) which looks similar to the SRT filter but has a funnel/velocity stack on top which is great for a ram-air type setup. Not sure which to choose...what do you guys think?
Old 08-06-07, 07:41 AM
  #2  
Rock-a-Lex
Lead Lap
Thread Starter
iTrader: (4)
 
Rock-a-Lex's Avatar
 
Join Date: Jan 2007
Location: NY
Posts: 4,519
Received 17 Likes on 16 Posts
Default

No one can add some info on this topic? There HAS to be a performance difference when using different size filters (different volumes). I'm thinking too large of a filter and there goes your low-end power but great top-end...similar to an exhaust. A very large exhaust will kill your low-end but help your top-end. Do you guys agree?
Old 08-07-07, 08:55 PM
  #3  
JBrady
Lexus Champion
 
JBrady's Avatar
 
Join Date: Feb 2001
Location: Texas
Posts: 3,124
Received 30 Likes on 24 Posts
Default

Bigger is better as far as filters go.

Lowest possible pressure drop AND the straighter the air flow through the filter. Some K&N filters (and possibly other manufacturers) utilize a bell-mouth at the transition to the pipe section which can increase flow/decrease pressure drop.

This is of course all else being equal. You also want the COLDEST air possible. A sealed from the underhood airbox with only outside air getting in through a large area to prevent pressure drop.
Old 08-07-07, 09:09 PM
  #4  
mex lex
Lexus Champion
iTrader: (4)
 
mex lex's Avatar
 
Join Date: Dec 2006
Location: Kyoei USA
Posts: 3,214
Likes: 0
Received 2 Likes on 2 Posts
Default

I don't think the filter has anything to do with topend low end as much as the pipe diameter. Such as the srt for example, members with the srt claim they lose low end in exchange for top end because of the 3.5 diameter pipe size when most other intakes for the GS, I believe, are 2.5-3.0 inches. As far as the filter, I would think bigger is better.

Quick question, jbrady, can you please explain what lowest possible pressure drop mean? How does that play into intakes? Thanks.
Old 08-07-07, 09:18 PM
  #5  
GSteg
Rookie
iTrader: (15)
 
GSteg's Avatar
 
Join Date: Jul 2005
Location: CA
Posts: 16,017
Likes: 0
Received 79 Likes on 61 Posts
Default

My guess is that he means the actual pressure of air going into the intake tube.

Our engines are naturally aspirated. We reply on the engine's piston stroke to suck air in. If we have some sort of restriction (like too small of a filter), it will hinder the engine's ability to pump air in. When there is a restriction, there is less air intake velocity and increase in pressure drop.

Naturally, our NA cars will acheive 14.7psi of air intake at most (sea level). It's important that we try to take advantage of this pressure by not creating a bottleneck in the intake system (filters are usually the culprit).

jbrady, correct me if I'm wrong.
Old 08-07-07, 09:22 PM
  #6  
mex lex
Lexus Champion
iTrader: (4)
 
mex lex's Avatar
 
Join Date: Dec 2006
Location: Kyoei USA
Posts: 3,214
Likes: 0
Received 2 Likes on 2 Posts
Default

Oh ok I see. Thanks for clearing that up
Old 08-08-07, 11:09 AM
  #7  
Rock-a-Lex
Lead Lap
Thread Starter
iTrader: (4)
 
Rock-a-Lex's Avatar
 
Join Date: Jan 2007
Location: NY
Posts: 4,519
Received 17 Likes on 16 Posts
Default

Perfect! Thanks for cleaing that up as well GSteg!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rselby
IS F (2008-2014)
4
06-06-14 10:09 AM
jbw
Performance
3
04-04-07 07:13 PM
tfb5701
LS - 1st and 2nd Gen (1990-2000)
6
09-19-03 04:53 AM



Quick Reply: Building an intake...



All times are GMT -7. The time now is 08:23 PM.