Help! I’m an EVO, stuck in the body of a Talon!
Help! I’m an EVO, stuck in the body of a Talon!
Posted by 640774n6 on March 6th, 2014
Evo 8 ECU
After cruising the forums over at dsmtuners.com¬†looking for tuning options to support my 650cc injectors, I found this thread¬†about installing an Evo 8 ECU in a 2G DSM. The Evo 8 ECU is flashable using ECU Flash and a Tatrix OpenPort 1.3 or 2.0 flash cable. Apparently 98 – 99 DSM’s had a flashable ECU as well and is completely plug and play, but after much research I decided on the EVO 8 because it was well supported by the EVO tuning community and I could also take advantage of TephraMod (patched roms adding features and fixes). I found one on eBay for $120 (heck of a lot cheaper than DSMLink).

The installation process was relatively simple. The ECU wiring harness needed to be re-pinned so that the proper sensor/trigger wire wen’t to the correct pin on the Evo ECU. This was a PITA, but not rocket science. I also had to wire in a flash port for the tatrix cable to the empty flash pin on the harness. The flash port is an older style Mitsubishi diagnostic port. I obtained mine from a Mitsubishi 3000gt I found at the local pick n’ pull.

Since I was doing this to my 95 7-bolt Talon TSI (which has an inverted cam angle sensor), I would need to either re-pin the injector wires and swap my spark plugs, or install a cam angle sensor with the proper signal. I decided to go with a 1G cam angle sensor because it is adjustable. I picked up my 1G to 2G conversion cable from RTM Racing and installed the cam angle sensor.

Once everything was installed, I dumped a copy of the stock Evo 8 rom for backup. Before I could start the car for the first time, I needed to flash a rom with the immobilizer disabled. An Evo 8 has an immobilizer system which my Talon does not have, therefore, the ECU would never receive the code signal it was patiently waiting for before enabling ignition. The immobilizer was easily disabled through the periphery bits in ECU Flash.

I also needed to change my MAF Scaling and Injector Scaling/Latency to match my injector size and 2G MAF size before attempting to start the car. I was able to get the MAF Scaling from a 2g DSM 98-99 ECU rom dump and found the proper Injector Scaling and Latency for my 650cc’s on a dsmtuner thread. These scalings are by no means cut and dry, they are just a good starting point. You have to dial them in by flashing them, driving and logging, adjusting, then flashing again, repeat, until the logs are indicating the proper values.

After making the necessary changes to a TephraMod v7 rom, I flashed it to the ECU and started the car. I needed to adjust the idle, but other than that, it seems to run just fine. Once I had the car running, I disabled a bunch of check engine light codes relating to my EGR (which is deleted) and rear O2 sensor (no cat). I also enabled the TephraMod “Flash Check Engine Light on Knock” feature and the Rear O2 sensor simulator.

Still waiting for my AEM UEGO wideband O2 sensor to come in the mail before I do any real tuning.

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