I did this mod the other day and i was wondering what yall guys think of it well wut i did was pulled the vacuum line off the flapper valve and i noticed it really doesnt have any vacuum at all. So i jsut put a screw in it to close it and then i tee into a strong vacuum line and run it to the flapper valve so im thinkin at part throttle the vacuum has the valves closed to gain low end torque but wen u wanna hammer it the vacuum lets off and allows the valves to open to gain more power up top.

Im not sure if my theory is correct but id like some input from u guys about this. To me it felt like it had way more part throttle power and the power didnt seem to drop off aftr each shift at low rpms

 

its there for a reason, i would leave it be, I havent heard anyone get any gains from it. and definetly no dyno proof

 

there is ABSOLUTELY no gain from taking off the line. You loose gas milage and mid range, but NO power gain.

PERHAPS, if you took out the entire plate, you could gain 1 or 2 HP because you are shortening the runners, but I don't know if that would work out to your benifit or not.

 

There's a vacuum solenoid that opens the IAB's at 4800 rpms. It's not load sensitive.

Search. There's been discussions on this topic before some interesting pics of mods.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jackstands &raquo;</TD></TR><TR><TD CLASS="quote">There's a vacuum solenoid that opens the IAB's at 4800 rpms. It's not load sensitive.

Search. There's been discussions on this topic before some interesting pics of mods.</TD></TR></TABLE>


o i see no wonder the valves werent closed at idle so thas why i added the stronger vacuum to it to have it close with light load but then wen i loaded it up it would open up for me but i really did notice a nice difference compared to the factory way

 

i have my IAB's running off my manni vacuum...it only opens at WOT...if you leave them open all the time you can get poor gas milage and loss of mid range...hook it back up ...

 

the butterflys need to activate based on rpm, not load. with them hooked up directly to a vac source you are basicly using engine load to open them. not a good thing. hook it back up the way it came or take the butterfly plate out completly

 

What would happen if you took the hose off peroid because i dont think mine has a hose going to it

 

you loose power below about 4000 rpms

 

so how do i fix this

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93sleeper &raquo;</TD></TR><TR><TD CLASS="quote">What would happen if you took the hose off peroid because i dont think mine has a hose going to it</TD></TR></TABLE>

Do H23s even have the two sets of runners?

 

ive had it unhooked for a while before i did that mod of puttin the other vac line on it and jsut look at my sig and wut i run so i dont really see me losing much power stock motor nothin done but bolt ons

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93sleeper &raquo;</TD></TR><TR><TD CLASS="quote">so how do i fix this</TD></TR></TABLE>

You need to make sure you have the vaccum box (#12) on the bottom of the IM and then hook up the lines properly.



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xthephilx &raquo;</TD></TR><TR><TD CLASS="quote">Do H23s even have the two sets of runners?</TD></TR></TABLE>

Yes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Pullig &raquo;</TD></TR><TR><TD CLASS="quote">ive had it unhooked for a while before i did that mod of puttin the other vac line on it and jsut look at my sig and wut i run so i dont really see me losing much power stock motor nothin done but bolt ons</TD></TR></TABLE>

reading is key to life... with the line hooked up how you have it, power below about 4000 is effected... how often are you below that at the track... NONE. those things are for putting around town, not racing.

 

fyi everyone, the IABs are held closed at idle all the way to 4800 , then the ecu activates a solinoid which cuts vacume to the butterflys and then they are sprind loaded so they open up

 

i dont know how yalls is but with mine set up stock the IABs are open at idle and with the car off they are open also. according to http://www.92lude.com they stay open untill a vacuum source closes them go check the site and he has the manifold takin apart and the butterflies sit wide open

 

Yours aren't working right, then. Starting the car (vacuum) should close them and if you rev the engine with your hand on the throttle rotor, you can clearly see them open at 4800 or so rpms.

 

yeha man no vacuum at all from the vac line that connnects to the iabs

 

I cracked open the intake manny, pulled out the plate, unscrewed and took out the 4 butterfly doors and threw the plate back on...then again, I'm going bost and using a p28 witch doesn't control them either way. Not sure if I noticed a difference seeing that I have nothing to compare it to because I took them out at the same time I upgraded the turbo and fuel managment. Shoulda checked. Oh well, if anything, I can see it making a difference on a boosted application more so than just having it as one of your only mods.

 

Hey guys finally got around to figuring out my problem and i think i found the problem the IAB control solenoid valve looked liek it shorted out and caught melted so thats why my IABS werent opening and closing properly. So does anyone know where i can get a cheap replacement. I need the IAB solenoid valve and IAB vacuum tank and i will need the plug that plugs into the IAB solenoid valve becuz the other one melted also.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ludelvr &raquo;</TD></TR><TR><TD CLASS="quote">I cracked open the intake manny, pulled out the plate, unscrewed and took out the 4 butterfly doors and threw the plate back on...then again, I'm going bost and using a p28 witch doesn't control them either way. Not sure if I noticed a difference seeing that I have nothing to compare it to because I took them out at the same time I upgraded the turbo and fuel managment. Shoulda checked. Oh well, if anything, I can see it making a difference on a boosted application more so than just having it as one of your only mods.</TD></TR></TABLE>
Yea man, I am doing the same thing, I am boosted now and building my motor and I was wondering if you can just take off those four butterflys and the egr valve since I'm running a p28 right now. Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maxvtec7500 &raquo;</TD></TR><TR><TD CLASS="quote">
Yea man, I am doing the same thing, I am boosted now and building my motor and I was wondering if you can just take off those four butterflys and the egr valve since I'm running a p28 right now. Thanks</TD></TR></TABLE>

I don't have my EGR or the four individual butterflies... I plan to get shorter studs and bolts so that I can just remove the plate all together...

 

hey sam1 do you have the part that im looking for

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">

I don't have my EGR or the four individual butterflies... I plan to get shorter studs and bolts so that I can just remove the plate all together...</TD></TR></TABLE>
Thats a really good idea, just eliminate it all together!