secondary butterfly question

[Rome702]

actually...you are wrong...visualpoet, wed3k, are right...they open up at higher rpms...not only is this found in the manual...it has been confirmed a couple times by members here.

So WHERE does the hp generally increase on the dyno when you remove the IAB's? Bet you do not know.

There is a hp increase AND a decrease...bet you did not know that either.

the valves close when vaccum is applied at higher rpms. the aib is an air intake bypass, which shuts down half of the intake manifold. if they close with a vaccum when you start the car, then how does it open back up with more vaccum at higher rpms. open you manifold up, and you will find that the butterflies are open (I know cuz i have already done all of this). When you open you manifold, you will find that they are open, and close when vaccum is applied at higher rpms. you do not get a decrease in power, only a little decrease in low end torque.

Basically, how does something close with vaccum and opens back up with more vaccum?

[904drACCORDMANG]

the valves close when vaccum is applied at higher rpms. the aib is an air intake bypass, which shuts down half of the intake manifold. if they close with a vaccum when you start the car, then how does it open back up with more vaccum at higher rpms. open you manifold up, and you will find that the butterflies are open (I know cuz i have already done all of this). When you open you manifold, you will find that they are open, and close when vaccum is applied at higher rpms. you do not get a decrease in power, only a little decrease in low end torque.

Basically, how does something close with vaccum and opens back up with more vaccum?

The signal from the ecu Closes the valve in the black box stopping all vacuum to the iab, ill make a vid tomorow so you can see the valve close as SOON as the vehicle starts

[bcjammerx]

Basically, how does something close with vaccum and opens back up with more vaccum?

Because you obviously do not understand how this system is actuated...

Advice...(because I used to do this exact same thing)when EVERYONE is telling you that you are wrong...you JUST MIGHT be...so...double check...trust me on this one

There is a device that the ecu actuates to control the vacuum...you need the black box and the pt6 ecu to make use of the IAB system. If you just hook up the vacuum line to the intake plenum it will work the opposite of how it really should;

vacuum applied equals valves closed
no vacuum equals valve opened

the ecu controls when vacuum is/not applied...by way of the vacuum switching valve (BYPASS CONTROL SOLENOID) and a vacuum storage tank.

[Rome702]

Because you obviously do not understand how this system is actuated...

Advice...(because I used to do this exact same thing)when EVERYONE is telling you that you are wrong...you JUST MIGHT be...so...double check...trust me on this one

There is a device that the ecu actuates to control the vacuum...you need the black box and the pt6 ecu to make use of the IAB system. If you just hook up the vacuum line to the intake plenum it will work the opposite of how it really should;

vacuum applied equals valves closed
no vacuum equals valve opened

the ecu controls when vacuum is/not applied...by way of the vacuum switching valve (BYPASS CONTROL SOLENOID) and a vacuum storage tank.

Im using a p13 that has been chipped, and have eliminated the aibs. I have only had good come out of it, as well as all my friends in vegas that have done it. It still doesnt make sense as to why it is better to keep them, when ALL aftermarket intake manifolds dont use them or offer elimination kits.

[visualpoet]

Im using a p13 that has been chipped, and have eliminated the aibs. I have only had good come out of it, as well as all my friends in vegas that have done it. It still doesnt make sense as to why it is better to keep them, when ALL aftermarket intake manifolds dont use them or offer elimination kits.

How many aftermarket manifolds for the F have you seen?
The closest I can think of is for the H23, and it's a sheet metal type manifold by OBX. From what I hear, it's a pretty useless manifold on the F without some other serious changes because the sheer volume of air it holds is too much for a car that's not built to use that much air at the low end.

If the secondary butterflies serve no purpose, why are there secondary butterflies on 4 barrel carbs? Why not just leave those out as well?
Because in the low end, with them open, they suck in more air than they would if closed, and it throws off the A/F mixture enough to affect power output.
The same thing happens, but less noticeably, on our injected engines than on a carbed engine, but they're still there for a reason.

Would you remove the butterflies from the intake scoop on a pro dragster? That's an aftermarket intake, but with the butterflies outside of the manifold, instead of inside. Same principal though. Too much air at lower rpms can be just as bad as not enough at higher rpms.

I'm curious, what else did you do to your car at the same time the secondary butterflies were removed? Unless you did nothing else except remove them, you can't say that there was no difference in the low end. You also have been insistent that they closed at high rpms restricting airflow. Possibly something was hooked up wrong on your car causing them to work backwards, and simply removing them bypassed the problem. It's possible you could have switched a couple of vacuum lines and resolved the issue without removing them.

[bcjammerx]

Im using a p13 that has been chipped, and have eliminated the aibs. I have only had good come out of it, as well as all my friends in vegas that have done it. It still doesnt make sense as to why it is better to keep them, when ALL aftermarket intake manifolds dont use them or offer elimination kits.

that's great...glad your butt dyno works...however they are not accurate.

But I am fully aware there can be benefits of removing them...there are pros and cons...but that was not an issue and not what we were discussing...you seem to be bringing this up to detract from the original complaint we are having with you.


You still have not addressed ANY of the issues/questions from my previous post either...that you are wrong in how you say the system works.

[Rome702]

that's great...glad your butt dyno works...however they are not accurate.

But I am fully aware there can be benefits of removing them...there are pros and cons...but that was not an issue and not what we were discussing...you seem to be bringing this up to detract from the original complaint we are having with you.


You still have not addressed ANY of the issues/questions from my previous post either...that you are wrong in how you say the system works.

regardless of how the system works, the butterflies for a dragster has to do with the throttle body. Skunk2 makes an aftermarket intake manifold (NO AIB), blackworks (NO AIB), BLOX (NO AIB). The aib is an air intake bypass used to reduce turbulence in the manifold. When deleting the butterflies i also ported out the aib plate itself, so it is big opening instead of having 8 separate holes. im also running it on an h23 with an h22 head not the f22 motor. also you wouldnt remove the butterflies from a carbed motor, cuz it doesnt use a computer to adjust a/f ratio

[wed3k]

admit it, you were wrong.

[dano28]

The purpose of the Honda secondary throttle plates is not only to add extra air. The other purpose is to offer an air supply that is closer to the intake valves.

Actually, some say creating shorter runners is the main purpose of secondaries.

Remember...Long intake runners for low RPM power. Short intake runners for high RPM power.

[visualpoet]

admit it, you were wrong.

Won't happen.

[envy]

my mechanic said that my iab is not working, he says if he connect it to the power it will open but thats all

[904drACCORDMANG]

what you should do is look at the arm on the iab plate, and note its position while the car is OFF. Now start the car and see if the arm moved, if the arm moves that means vacuum is closing the butterflies and you have an electric issue. If it is in the same position wether the car is runing or not then you have a vacuum issue

[Phate]

regardless of how the system works, the butterflies for a dragster has to do with the throttle body. Skunk2 makes an aftermarket intake manifold (NO AIB), blackworks (NO AIB), BLOX (NO AIB). The aib is an air intake bypass used to reduce turbulence in the manifold. When deleting the butterflies i also ported out the aib plate itself, so it is big opening instead of having 8 separate holes. im also running it on an h23 with an h22 head not the f22 motor. also you wouldnt remove the butterflies from a carbed motor, cuz it doesnt use a computer to adjust a/f ratio

The reason aftermarket intake manifolds don't typically have IABs is because it is more expensive to design a proper dual runner intake manifold, and generally when someone is putting an aftermarket intake manifold on an engine, it is because they are building a race-type engine, and there is a focus only on higher rpms and peak power.

Peak power is not everything, and its the power under the curve that really makes the difference. If you drive it on the street, your car isn't a fucking race car, and it rarely spends time up in the high revs. Time to learn something about the effect of runner length on powerband. The engine makes more power at low RPM using only the longer runners, making for better low end for drivability. At higher RPM, shorter runners will make more power, so the secondaries open up and allow the shorter runners to do their thing to keep the powerband going up into the high revs. You lose negligable power when you leave them in, while improving power in the low revs and midrange. On a race car, this wouldn't be a a concern, but a street car isn't a race car.


Because of this, the motor I'm building is going to have one of the dual runner intakes on it (probably the H23 IM, because it will be a 2.3 bottom end and the extra volume can't hurt). The long primary runners will give me torque at low revs, and the short secondaries will let it breathe well up high.

Anyways, TL;DR: You need to learn what the fuck you are talking about before arguing with people.

I think I've finally gotten my 30th post in the beginner section so I can start dropping knowledgabilities elsewhere.

[904drACCORDMANG]

You get those iabs figured out ENVY?