I know my h23a1 has programmed fuel injection....but what exactly does it do?
I heard something about 2 stages in the intake or something like that. Anyone care to inform me?

 

*BUMP* Anyone?

 

PGM-FI like you said is programmed fuel injection, your fuel injection pulse width is determined by your ecu, therefore programmec, you also happen to have what some people calla a dual stage, 2 stage intake manifold, whatever you want to call it. They are refferring to the IABs (secondary butterfly valves) in your intake manifold which open up around 4800 rpm I believe and make your car get alot louder and in theory allow for optimum air velocity...however they are the same on the h22 and the h23, so they thats why they allow for optimum air velocities *in theory*

 

hmm could this by why...my car (f22a sohc non-vtec) gets much louder at 5000 rpms? i said it before but people just said its my car screaming cause im takin it to high...which i didnt find funny at all. lmao

 

I was readin on a prelude website....and it said you can get into the actuators for the butterfly valves and wire them so theyre always open...giving more low end power. Has anyone else heard of it? Is it effective?
Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TPreludeSi &raquo;</TD></TR><TR><TD CLASS="quote">I was readin on a prelude website....and it said you can get into the actuators for the butterfly valves and wire them so theyre always open...giving more low end power. Has anyone else heard of it? Is it effective?
Thanks</TD></TR></TABLE>

or you can just take them out... heh.


here is the butterflies open (what happens at high rpms)



and here it is when they are closed

 

how can we keep em open all the time w/o removing them?

 

Im guessing theres some sort of actuator that can be forced to the open position. I made the aux valves on an older car of mine always open by doing that sort of thing.

Does anyone know how to do such a thing? What are the advantages disadvantages? Something makes me feel like torque would be lost...and the compression would get worse.....but I dont know.

has anyone done such a thing?

 

From what I've read, the IAB is activated by a solenoid that gets power from the distributor and a signal from the ecu. If you find out what voltage that signal is you can just add another wire and adjust the volatage with some resistors. But if you don't mind it looking rigged, you could just tie it open with a piece of wire or something.

 

Ok kiddies, let me step in here.

You can leave the IAB's open all the time by simply removing the spring on the acuator and holding the plunger down with a zip tie etc. I've heard you can actually leave them open by just yanking the vac lines from the acuator and vac box underneath the manifold, thou i've never seen this personally. Lastly, removing or "opening" the IABs will not give you more low end, it will in fact give you less, thus being the whole design behind honda using IABs in the first place. Its not that noticeable when they open, certainly not to a point where you would hear it...... IMO leave them the way they are, unless you're running a major FI setup, you won't benefit any from removing them otherwise

 

Thats what I thought...thats why I posted before I did it. Thanks.

 

here is a thread that will give you a better understanding of how the secondary butterflies operate.

https://honda-tech.com/zerothread?id=305211

And here is why removing them is a bad idea

Discussion: https://honda-tech.com/zerothread?id=634796

The results: https://honda-tech.com/zerothread?id=648786

Edit: Damn you spoolinlude, you beat me to it.