I have been doing a lot of reading, but there are tons of oppinions and no one specifies their findings for Daily driving vs WOT. So, here is my attempt to sift through it a little bit.

I know what the IAB's do, and that having them engage helps preserve some of the low end torque in your lower rpm ranges. I also know that a lot of people remove the butterflies because it shifts a couple lb/ft of torque and 2-3 hps up into the post 4.5-4.9k rpm range which is great for the quarter mile or bigger track racing.

I use my car as a daily driver and would leave them alone asside from one thing. I recently switched to a chipped p28 ecu because i am deleting my cat, want to put a neptune/hondata in, and do a lot of fine tuning down the road. I know that the p28s have no IAB control.

Now for the actual question. With no real engine internal work done at this point, would it be better to remove the vacume line and let them stay open all the time or not. Will the p28 basically be running under the assumption that there are no IAB's since it doesn't think there are any there thus running low AFR's untill the iabs open with vacume loss, or does it adjust to match the AFR's anyway and it won't really matter.

I know someone is going to post that i should gut it because i will gain 2-3 hp in the top end... I understand that. But, being a daily driver, i don't spend much time in vtec even other than when i am out playing around. My question here is, with the p28 am i now losing low end with them closed since it doesn't know that they are closing.

 

Should have use a P72 instead, will do everything a P28 does plus knock and IAB but at this point I would just get a Euro R manifold and a tune to regain the lost torque.

 

I'm probably going to get a p72 when i add hondata/neptune anyway, but when my o2's started going out i got the ecu from a friend with an h22 swap into is civic so i figured for free might as well try it out so i can get out of limp mode.

 

The ecu will tune itself with the O2 sensor in closed loop. You could hook the iab to vtec so it opens at the same time. Also, there is a way to add IAB control to a P28. Then use a P72 rom or whatever to enable it in the software.