FQS Fuel Logic Questions

[johnb]

OK here we go, actual measurements:

0 - 0
1 - 1.143v
2 - 1.754v
3 - 2.281v
4 - 2.516v
5 - 2.839v
6 - 3.048v
7 - 3.254v

These look to be roughly the mid points between the voltage cutoffs from my previous post, as expected.

[Tom]

You guys are awesome! I wonder why they kept the voltage steps so close together?

[whalenlg]

I have simulations running, but there is no change when I use different fqs settings (thanks @johnb ). I hadn’t tested for fqs changes so far, so I guess that shouldn’t be surprising. I’m also fighting with a different simulator that runs 10x faster, but with diverging results.

[pizatski]

I just wanted to chime in here and say I see the exact same thing. In order to hit target AFRs above 5K rpm, I've had to significantly enrichen the AFR targets in the WOT map for cells in 5520rpm and above regardless of FQS position. This was minimal with my stock injectors at 3bar. It's much more exaggerated with my 55lb injectors at 3bar.

I also have an older 24 pin 'Max HP III' DME chip I read and loaded into TunerPro - they had to do the same thing.

I wonder if the load or pulse width calculation assumes some weird air restrictions, reduced boost, or something else that happens above 5k rpm that I don't have with all the hardware changes on the car (exhaust, downpipe, maf, wastegate, compressor wheels, etc...) which is making it even worse.

[Tom]

I just wanted to chime in here and say I see the exact same thing. In order to hit target AFRs above 5K rpm, I've had to significantly enrichen the AFR targets in the WOT map for cells in 5520rpm and above regardless of FQS position. This was minimal with my stock injectors at 3bar. It's much more exaggerated with my 55lb injectors at 3bar.

I also have an older 24 pin 'Max HP III' DME chip I read and loaded into TunerPro - they had to do the same thing.

I wonder if the load or pulse width calculation assumes some weird air restrictions, reduced boost, or something else that happens above 5k rpm that I don't have with all the hardware changes on the car (exhaust, downpipe, maf, wastegate, compressor wheels, etc...) which is making it even worse.

I'm reasonably confident I know what's going on after really digging into the code -- will post the details here as soon as real-world chips support/confirm my read of the code. It's kind of hiding in plain sight when looking at John's GitHub page on DME load calculations.