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-   -   y does a engine running a p72 that looks for iab's lack mid range power? (https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/y-does-engine-running-p72-looks-iabs-lack-mid-range-power-1622534/)

3s0n3 05-09-2006 03:38 PM

y does a engine running a p72 that looks for iab's lack mid range power?
 
i saw this quote on rywire... " IAB is only used in combination with the stock GSR intake manifold and stock P72 ECU. If your ECU looks for IAB's, and your intake manifold does not have them, your performance will suffer in the mid-range powerband.

y is that? and is there a way to fix it with out going obd1

YasRex 05-09-2006 04:24 PM

Re: y does a engine running a p72 that looks for iab's lack mid range power? (3s0n3)
 
If I were you I wouldn't worry about it. Just run the ECU with chrome or whatever, tuning it. That will be way better than any factory ecu program as far as performance.

Mr_CRX 05-09-2006 05:35 PM

Re: y does a engine running a p72 that looks for iab's lack mid range power? (3s0n3)
 
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 3s0n3 &raquo;</TD></TR><TR><TD CLASS="quote">i saw this quote on rywire... " IAB is only used in combination with the stock GSR intake manifold and stock P72 ECU. If your ECU looks for IAB's, and your intake manifold does not have them, your performance will suffer in the mid-range powerband.

y is that? and is there a way to fix it with out going obd1 </TD></TR></TABLE>

The reason Rywire says that, is because of this:

When you run a stock p72 computer, it engages VTEC at 4400 rpms and then opens the IAB's at approximately 5500 or so. This provides good midrange when used with the stock intake manifold.

When you run an intake manifold that doesnt have the IAB (such as a Skunk2 manifold for the GSR head), VTEC still engages at the stock 4400 rpm point, but there are no IAB's to open up at 5500 to keep a smooth powerband. The low-cams are still making more power than the high-cams up until approximately 5500ish (on a stock GSR motor, for example), so the motor just kinda falls on its face in VTEC until upwards of 5500rpm or so. Usually you can just raise the VTEC engagement point to 5500 to maintain a somewhat smooth powerband, but you'll need to get your car tuned if you want to make optimum power with that setup.

I'm not sure what you mean by "is there a way to fix it without going obd1" The p72 ECU is an obd1 ECU

crxnj 05-09-2006 05:37 PM

Re: y does a engine running a p72 that looks for iab's lack mid range power? (Mr_CRX)
 
i think this guy has an obd2 setup also..so what can he do with the ecu ?

Mr_CRX 05-09-2006 05:45 PM

Re: y does a engine running a p72 that looks for iab's lack mid range power? (Mr.speaker)
 
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.speaker &raquo;</TD></TR><TR><TD CLASS="quote">i think this guy has an obd2 setup also..so what can he do with the ecu ?</TD></TR></TABLE>

Can you run a VAFC or somethin similar on obd2? If so, you can just move the VTEC engagement point to compensate for not having the IAB's. Thats what I did on my b18c with a skunk2 manifold. I just raised it to 5600 and it pulls smooth. I havent gotten a chance to get mine fully tuned yet. It's not the best solution for the problem, but it'll make a pretty big difference.

3s0n3 05-09-2006 06:15 PM

so i should be good then since im using the stock mainifold. and obd2a p72. ?

Mr_CRX 05-09-2006 06:18 PM

Re: (3s0n3)
 
Yeah if you have the stock intake manifold, and the IAB's are hooked up correctly, you'll be fine with the stock p72 ECU


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