Overwhelmed by the process of tuning w/ the AEM FIC-6, I decided to bring my SC'd T4R to EFI Logics in Bethel CT to have them give it a go. 90+% of their work is with the Cobb (Subaru / Porsche) world and while they have never done an AEM FIC-6, one of the shop guys has an Isuzu Trooper w/ FIC-8 and said he'd help their tuning wizard learn the ways of the piggyback. Here's what I found when I gave it a spin:

1) AFRs under boost / high RPM drop down to the 11/12s - good
2) There is a significant increase in power in the mid-RPM range - almost feels like another supercharger - good
3) Fuel trims are all over the place after a boosted run - not good

When I asked how they felt it went (when I picked it up) they said that they felt the factory ECU was fighting the tune -- that the fuel trims weren't good. I would agree. In downloading the maps (attached) I think I understand why: there is no O2 map (it's all 0s). I'm also not sure what the MAF map is doing based on the way it's set up.

If I knew the target AFRs for their work I think I could create one now and try and bring the fuel trims under control. I've noticed that when the fuel trims go gonzo after a boosted run that the AFR lingers low (12ish) and meanders back to stoich.

What do you think? I can't blame them for trying (nobody else would touch a Toyota / piggyback) but I don't think I'm where I want to be w/ the tuning.

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I have no experience with MAF tuning, just isn't needed unless you have a larger intake than stock. The fuel trims are probably just fine, but know that the ECU will tune it all out except for the open loop ones in high boost.

The ECU is most definitely fighting the tune, and will de-tune all but the open loop portions at Wide Open Throttle (WOT).

I wonder in instances where a supercharger was installed by a dealer if they change/swap/adjust something to tweak the tuning for an SC? It would seem if Toyo designed the SC they would have taken into account any base ECU programming needing modifying for complete use of the SC. Otherwise it seems part of the HPs/torque are never achieved.

When you say that the fuel trims are not good, what do you mean?
The trims will be all over the place, that's normal. Since the Piggyback is tricking the computer into thinking it's running lean mixture (so it will run rich) the fuel trims adjust accordingly. Do you have an AFR guage? I would rely solely on the AFR and completely ignore your fuel trims.

Basically the stock ECU is trying to get the truck back to stoich (~14.7) so when getting into boost it's no longer getting down to 11-12 -- it's trimming out fuel as the O2 sensor is tipping it off that it's running "too rich". I need an O2 map to tell the ECU it's 14.7 when it's really 11-12.

My comment about it feeling like another supercharger was added -- that is when it went into open loop - it dropped into the 10-12 range and took off.

What are your fuel trims sitting at? I've tuned an Apexi safc piggy back on mitsubishi's back in the day and could get fuel trims pretty close to 0 or 100.

If your on stock injectors and fuel pressure the fuel trims should be fine since the ecu will take care of that. Just make sure lo and mid fuel adjustments are not changed. Only open loop map should be adjusted.

They’re like -20, -15 ... stuff like that. Stock ECU is effectively detuning my professional tune because there is no O2 map. I am running 380cc injectors so these #s aren’t surprising.

Trying to figure out where to start with the O2 map. I suspect since my truck has a wideband O2 sensor (Vs Narrowband), the values I need are in the 0-5V range. Wouldn’t I effectively be trying to tell the truck it’s 14.7 AFR throughout the closed loop? (What am I missing here?)

Yes, you have a Air/Fuel ratio sensor, not the narrowband like I have. Watch this video by AEM: https://www.youtube.com/watch?v=GZNDCT9UjQQ this is exactly what you need to do. Once you've figured out the voltage input for each AFR level, simply just put in the AFR you want in each cell. Voila, perfect AFR trims in closed loop. Done.

I've found my engine responds well with 13's in low boost after say, 2 PSI up to 5 or 6, 12's up to 9 PSI, and 11.8 from there on up. Adjust for whatever boost levels you see. Don't go too rich below 3000 RPM's though, it'll bog down the engine.

There's a bunch of how-to videos put out by AEM on how to use every feature of the FIC 6. I suggest watching as many as you have time for.

Not sure of the exact numbers, but when you want it to run rich, you'll need to trick the computer into thinking it's lean, not stoich. So you'll need it to output voltage at what would normally be something like 15.5-16:1. This will trick it into adding more fuel and thus, your fuel trims will begin to go into the + fuel range (or higher than what it was at). Mine routinely run around +10-15% when I'm in boost and it's working properly.

If you still have my number (can't remember if I gave it or not) give me a call. Much easier to explain than to type it all out lol. If not PM me and I'll get it to ya.