Honda Prelude Forum
 
Go Back   Honda Prelude Forum > Tech-Talk > General Tech Talk

Thread Title
intake air bypass butterfly valves?

 
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 03-09-2008, 04:27 AM
guti776's Avatar
Bronze Member
 
Join Date: Jan 2008
Location: Managua, Nicaragua
Posts: 117
iTrader: (0)
guti776 is on a distinguished road
intake air bypass butterfly valves?

hey, i got a question and i was wondering if anyone knows about this and can help me out. in the intake manifold there is a piece thats the IAB (intake air bypass) that piece has a set of butterfly valves. i heard that if you remove those there is an improvement in performance because more air comes in. they are supposed to open when VTEC kicks in or something like that. Others say that you shouldn't remove those because they help the car when its at low speeds while VTEC isnt in or something like that. what is their real purpose and should i put them back in, i took them off to experiment. my engine is an H22A1. only difference i can notice is that VTEC doesnt seem to Kick in as loud as it used to but still strong. why do they tell me to put them back in? how important are they and should i put them back on?

i have a pic of it, but i dont know how to put on here. it ask for my URL when i put insert image, how do i put it on here to shows you guys? i tried but nothing, only letters

Last edited by guti776; 03-09-2008 at 04:33 AM.
Reply With Quote
  #2 (permalink)  
Old 03-09-2008, 04:36 AM
BadMofo's Avatar
Platinum Member
 
Join Date: Jul 2007
Location: Riverton, NJ
Posts: 1,305
iTrader: (0)
BadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond reputeBadMofo has a reputation beyond repute
Send a message via AIM to BadMofo
They open at about 5000 and vtec kicks in at 5200... the difference in sound is because the sound often associated with "vtec kicking in" on our cars, is actually produced by those butterflies opening moreso than "vtec kicking in" itself... so by taking them out all together you don't notice the sound as much.

Removing them is benefficial when used in conjunction with other modifications that help your engine breath better, but I believe it only has a positive effect in high rpms... I believe that it hurts low end torque though. They stay closed at low rpms to increase the air pressure in the intake manifold I believe, and open at high rpms to allow for more air flow (remember... it's always about pressure and flow)... At high rpm your cylinders are creating enough vacuum that they need to be open to pull in an adequate amount of air... and at low rpm the increased pressure of having them closed helps your motors low end torque output... or at least that's how I understand it... someone else may know better though.


Edit: no need for a pic of it, i believe everyone on here knows what you're talking about... well everyone on here that can help that is =P.

I'd say to put them back in unless you are boosting or using nos, because removing them doesn't help in high rpms much other than removing the open valves themselves from obstructing the air path... which is trivial anyway... it's only change it's really making is that they aren't there for the low rpms... and that's when you want them there for your increased pressure... now if you are running boost... then removing them is beneficial because you don't need them there because you are creating more pressure with your s/c or t/c anyway, and having them removed will allow you to increase the flow as well!

Last edited by BadMofo; 03-09-2008 at 04:52 AM.
Reply With Quote
  #3 (permalink)  
Old 03-09-2008, 06:08 AM
yogi_pahl's Avatar
Platinum Member
 
Join Date: Oct 2007
Location: I'm on a boat
Posts: 2,274
iTrader: (1)
yogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond reputeyogi_pahl has a reputation beyond repute
Send a message via AIM to yogi_pahl Send a message via Yahoo to yogi_pahl
^^ is right unless u got a s/c or t/c dont do much if anything as for the pic thing u need to have it on the web like photobucket then u copy the link to that pick and put it in the box when ur done should look like this but with out the *

[IM*G]full pic link[/*IMG]
__________________

^^MY DREAM CAR Made by muha22752
Life's journey is not to arrive at the grave safely in a well preserved body. But rather to skid in sideways, totally worn out, with a beer in one hand, shouting "Whoo, what a ride!.
I'm no rocket surgeon ok It's not what i say but what i mean you got to read my mind to understand meŠ
GPC member #5
Reply With Quote
  #4 (permalink)  
Old 03-09-2008, 06:32 PM
guti776's Avatar
Bronze Member
 
Join Date: Jan 2008
Location: Managua, Nicaragua
Posts: 117
iTrader: (0)
guti776 is on a distinguished road
Quote:
Originally Posted by yogi_pahl View Post
^^ is right unless u got a s/c or t/c dont do much if anything as for the pic thing u need to have it on the web like photobucket then u copy the link to that pick and put it in the box when ur done should look like this but with out the *

[IM*G]full pic link[/*IMG]
thanks for explaining how to put the pics up, next time ill do that, thanks

Quote:
Originally Posted by BadMofo View Post
They open at about 5000 and vtec kicks in at 5200... the difference in sound is because the sound often associated with "vtec kicking in" on our cars, is actually produced by those butterflies opening moreso than "vtec kicking in" itself... so by taking them out all together you don't notice the sound as much.

Removing them is benefficial when used in conjunction with other modifications that help your engine breath better, but I believe it only has a positive effect in high rpms... I believe that it hurts low end torque though. They stay closed at low rpms to increase the air pressure in the intake manifold I believe, and open at high rpms to allow for more air flow (remember... it's always about pressure and flow)... At high rpm your cylinders are creating enough vacuum that they need to be open to pull in an adequate amount of air... and at low rpm the increased pressure of having them closed helps your motors low end torque output... or at least that's how I understand it... someone else may know better though.


Edit: no need for a pic of it, i believe everyone on here knows what you're talking about... well everyone on here that can help that is =P.

I'd say to put them back in unless you are boosting or using nos, because removing them doesn't help in high rpms much other than removing the open valves themselves from obstructing the air path... which is trivial anyway... it's only change it's really making is that they aren't there for the low rpms... and that's when you want them there for your increased pressure... now if you are running boost... then removing them is beneficial because you don't need them there because you are creating more pressure with your s/c or t/c anyway, and having them removed will allow you to increase the flow as well!
hey thanks a lot for the reply, think i'll put them back on jaja. makes a lot of sense that you are saying, thanks i really apreciate it.

Last edited by hotrod; 03-10-2008 at 05:15 PM. Reason: merging back to back posts
Reply With Quote
  #5 (permalink)  
Old 03-10-2008, 05:02 PM
PreludeBoy95''s Avatar
Platinum Member
 
Join Date: Aug 2007
Location: Corn Field, Iowa
Posts: 1,272
iTrader: (1)
PreludeBoy95' is on a distinguished road
Send a message via AIM to PreludeBoy95' Send a message via MSN to PreludeBoy95'
ay welcome to PZ
__________________


:jester: Not-on-the-H22-bandwagon: Member #9


.:BBsquad.

Reply With Quote
  #6 (permalink)  
Old 03-11-2008, 02:04 PM
guti776's Avatar
Bronze Member
 
Join Date: Jan 2008
Location: Managua, Nicaragua
Posts: 117
iTrader: (0)
guti776 is on a distinguished road
Quote:
Originally Posted by PreludeBoy95' View Post
ay welcome to PZ
hey, thanks
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 06:36 PM.



Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors


Copyright © 2006-2009 PreludeZone.com All Rights Reserved.