P28 Vs P72

[LudeDude98]

EDIT- nevermind i found the information, thanks anyway.

Hi i am deciding which ecu to buy the p72 or the p28. the p28 is about 100 dollars less which is a plus, but on the website it says Secondary intake runner operation will be lost if a P72 ECU is not used. What is this? and will i lose power if i dont have the p72, any information is appreciated. thanks.

-Matt

[ONILSVTEC]

EDIT- nevermind i found the information, thanks anyway.

Hi i am deciding which ecu to buy the p72 or the p28. the p28 is about 100 dollars less which is a plus, but on the website it says Secondary intake runner operation will be lost if a P72 ECU is not used. What is this? and will i lose power if i dont have the p72, any information is appreciated. thanks.

-Matt

hey dood what did you find out? cause in going crazy trying to figure out what should i doo for my ls-vtec...cause i have a p72 now but my friend wants me to trade ecu's with him for his p28...help me plz or email me @ onishima2k5@msn.com
ONILSVTEC

[RMS]

P28 CAN HAVE IAB ADDED WHEN SOCKETING THE ECU! how is this not common knowledge by now? so can p05, p06, p07CA, p30, p61, pr4, p74, p75.

just like HOW IS IT THAT SO FEW HONDA ENTHUSIASTS DON'T REALIZE THAT OBDI ECUS DON'T CONTROL IAB IN OBDII CARS CORRECTLY WITHOUT MODIFICATION TO THE WIRING HARNESS?...or by correcting the signal polarity within the ecu like we do.

i think hondata would be good to add this into the application listing.

edit: all small frame jdm civic/'teg obdI ecus can have high or low-side iab output added now as well.

[mdpc20653]

same here i can't decide between a p28 or p72 help!!! i'm going n/a with vafc and bolt ons

[ZUUL]

... CAN HAVE IAB ADDED WHEN SOCKETING THE ECU! ... HOW IS IT THAT SO FEW HONDA ENTHUSIASTS DON'T REALIZE THAT OBDI ECUS DON'T CONTROL IAB IN OBDII CARS CORRECTLY WITHOUT MODIFICATION TO THE WIRING HARNESS?...or by correcting the signal polarity within the ecu like we do.

i think hondata would be good to add this into the application listing.

edit: all small frame jdm civic/'teg obdI ecus can have high or low-side iab output added now as well.

How is this done? The usual OBDII-B to OBD1 harness doesn't take care of this?
Do you know of any web pages with tutorials on this mod?
I have a OBDII-B GS-R that I plan to replace with an OBDI soon & want to make sure I do everything properly.

[RMS]

the obdII ecu sends a 12Volt signal out to the iab control solenoid.
the obdI JDM ecu senda 12Volt signal out to the iab control solenoid.

the obdI USDM ecu sends a ground signal out to the iab control solenoid.

so for an obdII to I conversion harness to work properly with a USDM ecu you have to add a relay to reverse the signal's polarity. or use a JDM ecu.

if you use a civic ecu with iab added we can correct the polarity within the ecu.

this means that using a JDM obdI ecu in an obdI USDM car also has the same conflict. we can correct this issue from within the ecu hardware, as well.

[M2Prelude]

So as I understand it, the H23 DOES have secondary runners, but footnote "4" is not annotated for the Si Prelude with the h23. I am an electronics techician and plan on socketing my own ECU (p28) if RMS or someone can give a little detail on how to add IAB to the p28. Also, why does the application guide not say to use the p72 for the h23?

Thanks for the help...