Simos 8.4 / 3.0t VE question

[mtb703]

Hi all, I'm trying to get my head around the workflow here, and I think I've got it pretty well figured out. I'm currently on a off-the-shelf 034 tune, but would like to try this myself come Spring.

Throttle requests % of max torque at a given RPM, which looks up airmass for requested torque. What it references from here I'm not quite clear on. I see what looks like a VE map of Supercharger RPM vs Pressure Ratio, does the ECU use this map to calculate manifold pressure? And then bleed off access air with the bypass valve?

The Speed Density tab seems to be all related to variable cam timing, which I don't believe this engine even has.

So if I put my car on a dyno, and my fuel calibrations were all correct, and my targeted lambda was different than actual lambda (edit: open loop obviously), it would be this pressure ratio map I would adjust? Or is there a different VE map?



Thanks for any help!

[mtb703]

Was this too remedial of a question? Kinda like "if you don't know the answer you should probably take a step back"? lol

[Lins]

I don't think there's a huge VW/Audi following just yet. I'm new but will be following as I have a coworker with an Audi S4 that might want to make some adjustments. My MPVI2 just showed up today.

[mtb703]

Right, hopefully.

And I thought about this map some more, its just a compressor map and should stay fixed regardless of what VE improvements happen downstream. Although I'd like to know what references it to determine how far it needs to be scaled since a pulley swap will run off both the RPM and PR axis.

[mtb703]

Okay, what I don't get is that most (all) of the load axis uses an air mass mg/stk with a max of 1389, its setup like there is a MAF, but there is no MAF. SIMOS 8.4/8.5 does have the functionality in the software, but our Audi implementation does not actually have a MAF. We only have MAP sensors.

[Exley]

Hi all, I'm trying to get my head around the workflow here, and I think I've got it pretty well figured out. I'm currently on a off-the-shelf 034 tune, but would like to try this myself come Spring.

Throttle requests % of max torque at a given RPM, which looks up airmass for requested torque. What it references from here I'm not quite clear on. I see what looks like a VE map of Supercharger RPM vs Pressure Ratio, does the ECU use this map to calculate manifold pressure? And then bleed off access air with the bypass valve?

The Speed Density tab seems to be all related to variable cam timing, which I don't believe this engine even has.

So if I put my car on a dyno, and my fuel calibrations were all correct, and my targeted lambda was different than actual lambda (edit: open loop obviously), it would be this pressure ratio map I would adjust? Or is there a different VE map?



Thanks for any help!

I think you're on the right track. I've been tuning my GTI which is Simos18. The logic sounds very similar. On the GTI you have Maximum torque at transmission and this is fed into pedal % then it takes this torque value and looks it up in the Torque to Aircharge table. On the GTI the car will try to achieve this cylinder airmass by targeting a MAP value. I would think the supercharged cars would do something similar with the throttle plate and bypass valve.

I have not attempted to change VE at all to bring my fuel trims inline. With how fast the closed loop correction on my car is, it's not an issue.