hello honda tech!
here is my scenario.. i have a 98 civic ex and a 93 civic si. the ex is clean but motor is completely stock. the si is in pretty rough shape but the motor is built with vitara pistons eagle rods and running 17lbs of boost. the si's ecu is chipped and tuned with chrome. i would like to know what more is there to it to swap motors and ecus from one to another(including putting the y8 in the si since it would make a great daily still). since they are both d16s i know mechanically they are the same and should pretty much drop in, but electrically changing from obd1 to obd2 may bring up some issues. especially since id like to pass inspection in new york state. but that is secondary to getting them both running. any help or direction to a informative thread would be greatly appreciated!!
Thanks!!

 

If you have to plug in, the tuned ECU with the Z6 will fail instantly in the EJ8.

 

I figured... I guess I will have to work around that.. Any idea of the engine harness or an odb1 to obd2 jumper harness?

 

Let me rephrase: You would have to keep the stock OBD2A ECU to pass emissions. You cannot (reasonably) tune an OBD2 ECU. There is no reasonable way to put the boosted engine in the EJ8 and still pass emissions for you. What you want to do is not possible, legally speaking.

Putting the D16Y8 in the 5G is easy, and could easily pass inspection. Putting the Z6 in the 6G is also easy, and could easily pass inspection with a little bit of wiring trickery. Keeping the Z6 boosted in the 6G and still passing inspection is not going to happen without finding a way to avoid having to go through emissions.

 

Ok thanks! I guess I'll worry about that when it comes time for a new sticker. Are the harnesses the same for these engines? Would the Ecu just be an unplug and plug back in deal? Or is there more to it?

 

Much more to it. The harnesses are entirely different, and the ECU plugs are not compatible. From a wiring standpoint, the motors are relatively easy to swap. Running the P28 ECU in the 6G is also easy - just buy a jumper harness. Running the P2P ECU in the 5G is not (within reason) possible.

 

Ok so I need another p28 to run the y8 in the 5g..? The harnesses would just stay with thier originally mated motors? And jumper harnesses for both? Just trying to get a shopping list together.
Thank you for all the info!

 

The harnesses would stay in their chassis'. The motors would swap over fairly easily. The P28 would work in the 6G, but you wouldn't be able to pass inspection with it. You would have to get a new ECU with a chip and tune to run the Y8 in the 5G properly, although I believe a virgin P28 would be able to run it.