the IAB system is not a very complex one. i was thinking for the b18c1 owners running p28 ecu's, if you use an msd rpm switch to power the vacuum solenoid at 5700 to switch over to the short runners.
thoughts?

 

Would work perfectly....... but at close to $100 for the msd system you could sell the p28 and get a p72. A cheaper option is to take one of those little shift lights (I forget where but they were like $25) and a relay and hook it up the same way. Or you could do it ghetto style and put a manual switch inside the car just to make people ask "what's that" you can tell em its your turbo switch and flip it at 6k (they'll probably believe you if they don't know dick about motors)

 

Actually, summit racing sells an RPM activated switch designed for shift lights for about $60. I have one but haven't gotten a chance to install it. I run a 95 GSR ecu but the IAB signal doesn't work due to the abuse the previous owner gave it.