so, after putting my OBD-I p72 in my 2001 GS-R, i found my Secondary runners are always open. I have heard that i have to rewire my IAB, but nobody seems to know exactly how to do it. I was thinking, since uberdata can "control" the ECU, is there a way to modify it to send the right signal to run the IAB correctly? or should i rewire the IAB itself?

 

i'm pretty sure once you burn a chip using an uberdata bin, it will convert the ecu to think it's a single-butterfly. within the program, you may have noticed that there are 4 fields to set vtec engage/disengage. these are for vtec crossover at WOT and part throttle.

anyways, just to be sure, try the uberdata forums...

http://www.ecimulti.org/uberdata/forum/index.php

-marc

 

thats what i initally thought too, but even with the OBD-I stock (J1 Clipped) it still leaves em open....hmmm....anybody know how to rewire the IAB itself?

 

One of the OBDs has the ECU provide ground for the IAB solenoid, which is already powered; the other provides the power for the IAB solenoid which is already grounded. Test the output of A17 on the OBD1 plugs going into the ECU for either ground or power at high RPM (or use Uberjunk to drop the IAB point low to make it easy) and then reverse it.