Intake control solenoid valve on a 1993 Honda prelude si. Boosted. This piece has been hanging around for awhile I don't think I need it anymore. So I was goin to unplug it and take it off.[IMG][/IMG]

 

Also I've found that this piece I glued on broke again do I really need it at all? Bypass control solenoid valve?[IMG][/IMG]

 

Bump

 

it looks like the IAB vacuum tank and solenoid. if you don't have an IAB intake manifold, remove it. and sell it, some people are looking for those.
*edit*
Just saw the IAB diaphragm, you do need that and your top end will suffer if it's not operational. But if you're boosted it might benefit you to remove the IAB butterflies and remove the box, especially if you're not using an IAB-enabled ECU.

 

I have a IAB manifold though, its the factory h23 manifold on my si. Can I hook it direct to the intake manifold even though I'm boosted or get a new black box or can I take it off or, unhook it?? Anyone know a quick fix with no power lose?

 

Can I just keep them in the open position all the time so I don't have to tear it down to remove them or should I rip it down and take them out? I am running a p75 ecu odb1 and hondata s300

 

just install the IAB circuit. you can't hook the IAB directly to a vacuum source or it operates in the reverse manner it's intended for. You can leave it disconnected but the top end will suffocate. worst case scenario you can remove the butterflies, but you'd be better off getting a different manifold since your low end will be soggy from the turbulence in the plenum.

 

remove the iab solenoid and the air box control box. none of it is needed.

i have iabs on my h22's but i run a vacuum line straight from it to the IM so that when you press the throttle more than 30~% they open.

 

I'm goin to unhook it then and if I don't like it I will goto the IM and they that.I don't see that they operate in reverse. Looks to me the more vacuum the more that open. But I just installed a turbo and I believe that's goin to mess everything up if I use them since the positive pressure in the IM rather than vacuum. Any ideas, better left in hooked???

 

Not positive on the H series stuff but the way the IAB on a GSR manifold works is that black canister you're holding stores vacuum from idle/part throttle driving then when the ecu signal's the IAB's to open, a solenoid allows the stored vacuum to open the IAB vacuum pot, then opening the butterflies. With no vacuum the butterflies stay closed therefore on the long runners for low RPM.

Some guys physically wire the butterflies in the open position but low rpm operation will be slightly worse. On my GSR I did not notice the low rpm loss on the "butt" dyno.

 

So to say if a turbo is installed then the IABs will not function correctly and need unhooked.is this statement correct? In know mine are open when the car is not running, I also know buy using a separate vacumm while cars not running I can close the butterflies. So its spring loaded in the open position now.

 

https://honda-tech.com/forums/honda-prelude-4/prelude-intake-maniflld-flapper-valves-3142881/

 

Turbo or not doesn't matter, the canister stores the vacuum with one way valves then uses that to actuate the butterflies when there is no vacuum in the intake manifold. (WOT/boost)