likwidchz

Hello


Anyone happen to know when IAB's open on the H22a?

what would happen if you rigged the IAB's so they were always open?

IAB rewire to vtec engagement? worthy/not worthy?


what does everyone think about this..?

Thanks.

95greenlude

IAB's open at around 4900 or so RPM

you would loose a little Tq in the lower RPM range

the IAB's aren't electronically controlled, its controlled by vacuum

likwidchz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95greenlude &raquo;</TD></TR><TR><TD CLASS="quote">IAB's open at around 4900 or so RPM

you would loose a little Tq in the lower RPM range

the IAB's aren't electronically controlled, its controlled by vacuum </TD></TR></TABLE>

The IAB's have a electronic solenoid attached to them..

That leads me to believe that once vacuum is sufficient at your 4900 rpm they slam open rather then slowly open as vacuum increases.

so any thoughts on rigging up IAB's to open when vtec engauges?

any Positives or negatives?

95greenlude

IAB's are Vacuum controlled....

i just went and looked at my spare IM, and there are not wires connected to it

likwidchz

Interesting...

My jdm H22a has the IAB vacuum line connecting to a solenoid then from that solenoid to the intake manifold.

It would be wired to the IAB solenoid wire on the P13

A17----pink---------IAB Solenoid Valve

*Edit*

I suppose you could simply not use the IAB solenoid but the IABs would open slowly as vacuum increased.

v4lu3s

it is a combo of vacuum and electronic. The solenoid is closed until 4900ish rpm when it opens and allows vacuum to open the IABs.
I have run the IAB on vacuum ONLY, removing the black box, running the vacuum line straight from the manifold to the diaphragm. In that setup the IAB would open anytime I was at more than about 1/4 throttle. It was fine on the track, but daily driving i noticed it felt weaker.

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by likwidchz &raquo;</TD></TR><TR><TD CLASS="quote">
Anyone happen to know when IAB's open on the H22a?

what would happen if you rigged the IAB's so they were always open?

IAB rewire to vtec engagement? worthy/not worthy?


what does everyone think about this..?

Thanks.
</TD></TR></TABLE>

Hi.

Roughly 4900 rpms.

Lose torque down low.

Not worthy. You need the velocity before VTEC engages.

You're not the first to think about this.

BTW, you're also overthinking it. If you want to run open IAB's, just remove the vacuum line. It's easy as that.

117

The IAB butterflies are closed mechanically by vacuum. There is a vacuum solenoid on the side of the IM. Underneath is a vacuum canister. The canister has an electric valve on it that determines whether or not the solenoid sees vacuum. No vacuum = IABs open, vacuum = IABs closed. AFAIK there is no in between.

You can control the opening/closing of the IABs by using a simple RPM controlled switch, or a switched output on a programmable ECU.

I run my IABs open all the time, and my car makes good torque. On top of that my exhaust is mostly 3" OD!! Oh the horror of the torque robbing open IABs and gigantic exhaust! On stock cams nonetheless!

117

Not quite. No vacuum = open. Vacuum = closed.

Closed throttle = high vacuum, WOT = very little or no vacuum.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">it is a combo of vacuum and electronic. The solenoid is closed until 4900ish rpm when it opens and allows vacuum to open the IABs.
I have run the IAB on vacuum ONLY, removing the black box, running the vacuum line straight from the manifold to the diaphragm. In that setup the IAB would open anytime I was at more than about 1/4 throttle. It was fine on the track, but daily driving i noticed it felt weaker.</TD></TR></TABLE>

likwidchz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 117 &raquo;</TD></TR><TR><TD CLASS="quote">The IAB butterflies are opened mechanically by vacuum. There is a vacuum solenoid on the side of the IM. Underneath is a vacuum canister. The canister has an electric valve on it that determines whether or not the solenoid sees vacuum. No vacuum = IABs open, vacuum = IABs closed. AFAIK there is no in between.

You can control the opening/closing of the IABs by using a simple RPM controlled switch, or a switched output on a programmable ECU.

I run my IABs open all the time, and my car makes good torque. On top of that my exhaust is mostly 3" OD!! Oh the horror of the torque robbing open IABs and gigantic exhaust! On stock cams nonetheless! </TD></TR></TABLE>

I I believe I am over thinking this, for some reason I got confused and figured IAB's open when there is vacuum but its the opposite..although I could simply just not connect the tube. I will experiment when the time comes and the engine is actually in my car -- As far as quasi open/closed IAB's I believe thats what the solenoid does once there is adequate vacuum which at 4900 rpm there would be plenty the IAB would slam open.

However -- if you gradually apply vacuum to the IAB vacuum line they open slowly -- using a vacuum gauge I had bought. This isn't a smooth open or close its kind of jerky though maybe thats because it wasn't designed to do that... maybe some geese/tinkering with the thing will correct it.. However I am just babbling and this might be something to test.

Either way -- the main idea behind this question was do you really gain much having IAB always open?


117 -- Do you have a dyno output of having IAB's controlled normally? or a simple before/after with your modification?


*EDIT*


So making the IAB always open or wire the IAB the stock way?

or get another Intake manifold and grind out the whole IAB section so its one nice big hole.

117

The electric valve that controls the outlet of the vacuum canister is open or closed. It doesn't regulate the amount of vacuum the solenoid sees other than vacuum/no vacuum. Don't forget that's why there is a canister there. It stores vacuum.

Trying to create a control system that gradually opens the IAB butterflies is more trouble than it's worth, IMO.

I do not have anything other than that. The car makes excellent power as it is. It's a track only car, so it wasn't worth the trouble to me to wire in the IABs with a P28 NepTune RTP ECU.

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 117 &raquo;</TD></TR><TR><TD CLASS="quote">I run my IABs open all the time, and my car makes good torque. On top of that my exhaust is mostly 3" OD!! Oh the horror of the torque robbing open IABs and gigantic exhaust! On stock cams nonetheless!

</TD></TR></TABLE>

Well, you're the exception to the case. Your motors are freaks anyways. But generally, for a bone stock H22, keeping the IAB's open will lose torque down low (wasn't there a few dyno tests on this?).

Also, for a road racing motor that probably never sees under 5k rpms, you don't need the IAB's.

117

I know. Didn't you see the ?

98vtec

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

Well, you're the exception to the case. Your motors are freaks anyways. But generally, for a bone stock H22, keeping the IAB's open will lose torque down low (wasn't there a few dyno tests on this?).

Also, for a road racing motor that probably never sees under 5k rpms, you don't need the IAB's.

</TD></TR></TABLE>

thats why you take the whole plate out

my motor generally made decent torque down low when i ran with the valve assembly removed

A Blue Lude

Reposting something from other thread...
.
.
.

Pirate gave us a direct IAB working/not working comparo on his special engine.

https://honda-tech.com/zerothre...14743

I have my own comparison, but it was on different days with different EMSes, that was causing the differences in VEETAK. Those top-end differences are not caused by IABs (in either case they're open past 4500 or so).

http://img262.imageshack.us/im...6.jpg

likwidchz

Well cool that helps a lot, I think ill remove it and not worry about it again

thanks!

InvaderTrax

Just to chim in, I picked up about 2mpg, when I fixed my IABs (were stuck open)

LukieLuc

I have had my IABs stuck open for a while the loss of torque down low sucks but i get over 30mpg on the highway going about 70mph and i have a h23 transmission. Even though i save on gas with them open, im in the process of getting them in working order

snobordboy

Sort of interesting to see how on both dynos posted above, there was a torque loss in the lower part of the rpm range, and although some may not think it significant, it was 5-9 lb-ft.
I think this could be exaggerated by other issues, such as altitude. I live at 5800 ft above sea level, and drive even higher alot. Driving up one of the highest passes in Colorado, which tops at over 12,000 ft, When my car was H23 powered and the IAB's worked, I could hold speed of 65+ MPH in 5th gear, with the accompanied revs of 3800-4000 rpm. After swapping to H22A, which although slightly smaller has higher compression, I could not hold these cruising speeds. If I dropped below 4300 or so rpm, the car would drastically lose speed, and I would have to downshift and accelerate at higher rpm to bring speed back above 65-70 MPH. These drives are both done with the H23 tranny btw, so no gearing differences.

This leads me to believe that having the IAB's constantly open at this altitude gives a fairly significant drop in low end torque. I unfortunately have not sourced a new vacuum box to have usable IAB's again, so cannot say for sure that this engine will perform that much better at those alititudes with them working.

LukieLuc

the vacuum line that goes to the box under the intake manifold, if its not connected and its out in the open will it mess with how your car idles?
I tried to cap it but, the car idled even shityer then its doing with it out in the open

Also, when you have your IABs open all the time, and your going up slight hills, your car boggs, asking for it to be at a higher rpm.

likwidchz

Honestly

the whole topic I started seems to have sparked some interest..

I mean I'm a technical person and when I received my H22A from HMO motors I started to look inside the intake manifold for ***** and grins and noticed this valve on the intake manifold. Once I learned the name of the IAB valves I took the manifold apart and looked inside and wondered why the hell would this do anything performance wise or gas mileage wise.


Granted I realize having a longer or shorter path for airflow from the throttle body creates more horse power either low rpm or mid or high rpm based on air pressure having a slight compression to it slightly before it enters the cylinders.

But it doesn't seem like the IAB valve would accomplish this task since the paths are really not that much different, there is only about 2 inches on each of the 4 IAB ports that separates both chambers...But then again they really don't seem to be separated chambers.

One would guess that If someone wanted more power they would grind all that **** out of the intake manifold and seal up the IAB mechanism that rotates the 4 butterflies inside that manifold, and possibly go ahead and polish the inside.


I don't know about it all.... anyone have any other advice/evidence??

theresyourproblem

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by likwidchz &raquo;</TD></TR><TR><TD CLASS="quote">One would guess that If someone wanted more power they would grind all that **** out of the intake manifold and seal up the IAB mechanism that rotates the 4 butterflies inside that manifold, and possibly go ahead and polish the inside.


I don't know about it all.... anyone have any other advice/evidence??</TD></TR></TABLE>

Lean is mean...well, unless your your talking about longevity..I like my motor...granted, I'm running it on a p13 which would make it pretty damn lean, but still. It's a choice, ONE or THE OTHER...black smoke beats busted rods, and waxing rear bumpers beats replacing blocks...follow?

Hawkze_2.3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by likwidchz &raquo;</TD></TR><TR><TD CLASS="quote">Honestly
Granted I realize having a longer or shorter path for airflow from the throttle body creates more horse power either low rpm or mid or high rpm based on air pressure having a slight compression to it slightly before it enters the cylinders.
</TD></TR></TABLE>

Where did you come up with that? Slight compression?...not that I know of.

Smaller hole = faster air velocity at lower rpms for more power

Bigger hole = not restrictive at higher rpms for more power (or at least not holding back the engine's airflow needs)


There's a TON of threads about this already, use the search feature and you will find lots of advice and evidence.

likwidchz

Yes, It is indeed what happens,

Its part of intake path tuning which is why some intake manifolds make more power then the other longer path from the throttle body to the head or shorter path from the throttle body to the head makes the peak hp either low end mid or high rpm ranges.

its exactly the same thing that happens tuning the exhaust side of any car which is called scavenging a exhaust pulse from one exhaust stroke creates a slight vacuum for the next exhaust stroke on another cylinder which is why they design 4-2-1 headers and also 4-1 headers both these header designs make power some low-mid-high ranges other just high rpm ranges depending on what your going for.

so tuning the intake side is just as important as tuning the exhaust side.

Hawkze_2.3

Yes, I have read about the overlap of pulses causing a little extra pressure, but the H22/H23 is not designed that way so I don't think deleting the IABs will give you that effect. If you had a custom manifold designed to utilize that concept that would be another story...