Well, well, well. It seems like every time I take another approach to tuning this beast I hit some kind of a ceiling or notice some odd behavior just as I get close to going all out. I continue to have a stock running crossfire with a great extra kick in the pants but never quite make it to the point where I feel comfortable putting the pedal to the floor and holding it to 6k.

So the latest update is that I scrapped going with a MAF based table and switched to what essentially would end up as a MAF delete by building a custom Map -> Maf voltage table. To do so, I built a base table and left the MAF connected to verify the MAF voltage for each cell. I've been tweaking the holy hell out of it and have it EXTREMELY close. The resulting curves are most definitely not linear and take quite a bit of finesse. The cool thing is that I have dialed in the theoretical injector percentage and can easily tell if a curve is off by the resulting AFR. Too much one way or the other and the same amount of fuel provides drastically different results.

That said, today alone, I made some great progress in getting it to the point where I feel confident I can start pushing her more. That was when I drove down a bumpy road and the car shut down on me for a crankshaft position sensor error. That I blame on the AEM FI/C and its crappy connectors.

I've noticed quite a few minor annoyances with the AEM over time and the weird things it does to the voltages it controls. Having all the extra wiring and depending so heavily on a piggyback just kind of makes me queasy. I started thinking about what would happen if I took it to the track and something similar happened. I could easily end up with a blown motor if not a wrecked car.

So then I decided to give our friend Rudy a call. I had seen that he had a couple of SRT-6 ecus for sale a while back and he did indeed still have them handy. I simply can't think of that many differences between what the ECU needs to see and neither did he. Lantana has been telling me to go with the SRT ECU from the start but I've been fixated on cracking this nut.

That said, I decided to pickup one of Rudy's ECUs and give it a try. I do plan on leaving the AEM in place and continue with my stock ecu tuning as I still want to prove that out to myself. I might also need it there for whatever things I might need to tweak with the other ECU. Regardless, the SRT-6 ecu will get me so much closer that in fact the aem could become more of a scalpel than a butcher knife in adjusting the tune (if it is needed at all).

Considering the stock SRT-6 ecu supports more boost than I plan on running and I have lower intake temps, wouldn't that be cool if I could make great power with oem tuning and safety with something as simple as an ecu swap and fooling a few sensors! I might have to pull a little timing but I am already running stock srt-6 injectors. I'm going to have to lookup and see if our MAP sensors are the same. The one in the N/A tops out at 3.8 volts at atmospheric pressure. It has a little room but not so much that I would think they are the same.

I checked the service manuals and so far this is what I came up with from the powertrain control module section:

Overall, it looks so far like the SRT wants to see the SC clutch and IC pump and the o2s are reversed. I already have the short runner system disabled and just have the solenoid plugged in but not attached. I locked the runners in high rpm mode.

Powertrain Control Module

• C1
  • Pin #1
    • N/A - Not Used
    • SRT - Supercharger Clutch Control
  • Pin #3
    • N/A - Sensor Ground
    • SRT - Throttle Control Motor #1

• C2
  • Pin #9
    • N/A - Not Used
    • SRT - Generator Control

• C3
  • Pin #7 - O2's reversed
    • N/A - O2 2/1
    • SRT - O2 1/1
  • Pin #23
    • N/A - O2 1/1
    • SRT - O2 2/1