I'm looking into swaping an USDM Evo VIII ecu into my 1996 Evo IV. My car is AYC equipped, not sure if that makes a difference. Does any one know what it will take to do this? Would a JDM CT9A ECU be needed or can this be done with a USDM Evo VIII ECU? I'm looking for a tune/flashable ECU since the Evo IV cannot be tuned and as far as I know, and ECU TEK is the only what to flash the V or VI ECU. A fuel system upgrade of at least the VIII pump and injectors is a must do am I correct. Any help would be appreciated thanks

Gabe

 

The AYC may cause a problem. Not sure if the AYC has it's own computer or not, but regardless it may still send signal to the Evo IV ecu. Its something I wouldn't really want to risk. It says your in Japan. Have you thought about going with the HKS standalone or Apex'i power fc? It should be no problem finding a tuner for either one of those there.

BTW I just want to say I think its pimp your wife drives an S15 Silvia!

 

I like how much online support ecuflash has ease of use. The price of a standalone is more than I want to spend. So I wanted to look into the ECU swap option first.

She wanted that car for a long time and when she found out we were going to Japan it was the only car she cared to own.

 

The AYC system has its own ECU.

You are better off going with the evo7 ecu as the pin outs are far more similar to the evo4-6 than the evo8 is, as the evo8 uses 3 connectors while the evo7 uses 4 connectors.

 

not all evo8 ecus are 3 plug ,ive a 4plug evo8 ecu in my evo4. theres a few pins to be swapped , fuel pump ,hi/lo rad and a/c fans ,you will need to run a wire to pin 79 for the white initializing plug as this isnt in the evo4 loom,also as the 4 doesnt have a heated o2 sensor you need to put in a resistor or wire in a 5/6/7/8 heated o2 sensor as i did .i used an evo8 harness path (4 plug) to make the pin changes though this isnt essential but makes life handy.
il post up a link to wire/pin changes

 

evo8 ecu ( 4plug) in evo4

swap pins 8 fuel pump and 22a/c comp
swap pins 32 and 34 rad fan and a/c fan
connect wire 20 to wire 32 and wire 21 to wire 34
run wire from pin 79 to use with white plug on tactrix cable
o2 heater circuit ( not in 4 loom)wire in resistor 15ohm 30 watt ,12v switched to one side of resistor and wire from other side to pin 60


evo7 ecu in evo4

swap pins 32 and 34 rad fan and a/c fan
connect wire 20 to wire 32 and wire 21 to wire 34
run wire from pin 79 to use with white plug on tactrix cable
o2 heater circuit ( not in 4 loom)wire in resistor 15ohm 30 watt ,12v switched to one side of resistor and wire from other side to pin 60


either ecu will need rom with rear o2 sensor delete patch

 

in a nutshell

 

Thanks for the info. What fuel system upgrades do you run?? What upgrade are recommended??

 

Evo4 has 510cc injectors std so fit evo 5/6/7/8 560cc injectors and walbro 255 fuel pump.also wise to fit new actuator (type with hat) and dont run any more than 1.2 bar boost peak.

 

Seen a lot of topics, but still can't found where I can get ROM for stock 510cc injectors (560cc is on the way to me), stock camshaft and MAF?
Or which TephraMod is better to modify for Evo4?

 

When you say you need added pin 79 a wire.
do you have a how to step with pictures to do this one I need to do the same thing .
I have a evolution 4 and I have a evolution 5 ecu to swap in .
Can you email me at rstoevo@gmail.com please
you will need to run a wire to pin 79 for the white initializing plug as this isnt in the evo4 loom,also as the 4 doesnt have a heated o2 sensor you need to put in a resistor or wire in a 5/6/7/8 heated o2 sensor as i did .i used an evo8 harness path (4 plug) to make the pin changes though this isnt essential but makes life handy.
il post up a link to wire/pin changes[/QUOTE]

 

If you can find an Evo V or VI ECU that would be ideal (no need to swap/add/cut wires). Just drop in and go. Otherwise the wiring mods as noted above will have to be done. PM me if you are interested in an aftermarket ECU that is plug and play.

 

This was great help ! I'm confused with the o2 heater circuit ( not in 4 loom)wire in resistor 15ohm 30 watt ,12v switched to one side of resistor and wire from other side to pin 60 though any wiring diagrams for this ?