Part 2: The J1 Powertrain

[prj]

What I was thinking is not adding a new device onto flexray, more have 2 flex rays interfaces, and relay messages that do interrogation of firmware, but consume functional messages. That said, I don't know anything how Porsche authenticates this firmware, so might leave it at that.

Please look up how flexray works, and also reverse engineer the flexray packing format, and realize how ISO-TP is packed into flexray frames on the controller.
Once you do that you will realize that your idea lacks merit.

That does make me think about something else however, would it be possible to design a man-in-the-middle device which would plugin between the ASG and the inverters, and simply scale the requested torque/power? A device like that was possible for Teslas for example.

Again. Flexray. Timeslots.
Have you seen how expensive it is to make something that talks on Flexray?
You'd need to do a whole ass FPGA with your own Flexray controller implementation in the FPGA that would be fast enough to MITM this stuff.

Furthermore, the ECU has monitoring. So it reads back the actual acceleration and torque parameters from the inverters, and a bunch of other stuff and if those don't match very closely what it's requesting - hard shutdown, no drive at all.
I got that the moment I started sending increased requests to the inverters, more than they'd want to give me. I bypassed that in the firmware of course, and then tried again, but no dice - inverters do the max they do and that's it.
Then you have the problem with the battery draw, that also won't match and there's monitoring on that too.

Doable in very remote theory. Yes. Would probably cost strong 6 digits to develop. I don't want to imagine the unit cost.

Don't compare a Tesla to this. The engineering in the controllers there are like childs toys compared to the ASG, which has monitoring functions and monitoring functions for the monitoring functions.

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[prj]

The OTA modules seems to have all the necessary buses, and an SoC which has enough horsepower to run a PIWIS equivalent which could interrogate other components and send the report back to the mothership. I think this might have been the original intent behind this module, with it flashing new firmwares remotely as needed.

Yeah, it is possible. TD1 is not checked like that. It is only checked during a warranty request, this is how it is at VAG. Internal info.

You can theorycraft more than I can ever answer.

 

[whitex]

You can theorycraft more than I can ever answer.

Thanks for replying. I shall stop the theorycrafting now to allow you time to write part 3

 

[Avantgarde]

The maximum torque is 340Nm, surprisingly there is a launch control mode, which bumps the torque up to 360Nm. The maximum power output is 480 PS, which means on the Taycan RWD it runs flat out in launch control.

Your claim around the hard torque limit for 340Nm for RWD seems to be confirmed by at least one person who did the RedShift Tune, using OBDII+Carscanner. Thanks for keeping the tuners honest on that.

My question is how do you conclude that 480HP is the hard Power limit for RWD? Understand that torque is limited by inverter controller. How do you conclude that torque drop >10K rpm is also based on hard limits? (Eg if the motor can maintain 340nm at 11K rpm that would translate to 525hp). Is there a hard limit on absolute max HP? Or are you estimating a power limit based on the torque limit and typical EV torque/power curve?

 

[prj]

Your claim around the hard torque limit for 340Nm for RWD seems to be confirmed by at least one person who did the RedShift Tune, using OBDII+Carscanner. Thanks for keeping the tuners honest on that.

My question is how do you conclude that 480HP is the hard Power limit for RWD? Understand that torque is limited by inverter controller. How do you conclude that torque drop >10K rpm is also based on hard limits? (Eg if the motor can maintain 340nm at 11K rpm that would translate to 525hp). Is there a hard limit on absolute max HP? Or are you estimating a power limit based on the torque limit and typical EV torque/power curve?

I am not estimating anything. I measured the smaller invcon by going 240 km/h in an etron GT.

These are the invcon curves period. There is no interpretation, no discussion - these are cold hard facts straight out of the ECU.

 

[Avantgarde]

I am not estimating anything. I measured the smaller invcon by going 240 km/h in an etron GT.

These are the invcon curves period. There is no interpretation, no discussion - these are cold hard facts straight out of the ECU.

Thanks. Is your solution ready to enable 360nm on the RWD without LC? Or is that something you still need to work on?

 

[prj]

Thanks. Is your solution ready to enable 360nm on the RWD without LC? Or is that something you still need to work on?

Yes, that's all done. I just want to do two things:
Check if it is possible to do more than 16000rpm on the dyno or if it's enforced by the invcon and test the new bootloader that I made, so that I can securely remote flash updates to the ASG should the need present itself.

Should be done tomorrow...

Part 3 is also done. Will post tomorrow as well.

 

[prj]

85kph would be 5100 rpm right ?
So based on your chart (suggestion btw: a stock vs what-i-am-selling chart would make this convo a lot simpler, at least to a seemingly IQ challenged person like me), stock torque at 5100 is 427 Nm ?

I added stock vs max (tuned) charts for every variant in Part 3.

 

[Rik_CT4s]

I added stock vs max (tuned) charts for every variant in Part 3.

Any idea why I get this reading with my Turbo S CT ...using carscanner.
Battery temp: 14C
83% SOC

sport sportplus (launch ready): abt 611 Nm max torque
Normal sport sport plus. Non launch ready: abt 551 Nm

Should be 1050Nm with TS no?

many thanks for ur insights.

Cheers

 

[prj]

I have no idea what Carscanner is logging and whether their conversion values are correct.
Seems like it's torque for rear inverter, but even then the correct values are 610 and 550, not 611 and 551.

You can ask them why they are displaying it incorrectly - I don't use carscanner, but from my short conversation with the author a while back they were empirically searching for values and formulas, so that is not a serious tool, but more of a toy.

I also don't think the total torque was even loggable via $22 on OBD, which CarScanner is using, but you can log front and rear motor torque separately. At least with ODIS or a tool using ODIS dump.
TQEM1 & TQEM2.

I am using factory level datalogging with A2L data, not dealer level, and definitely not toy tool level.
In the A2L the total torque is Elm_tqActSum_VW - but you can never get access to that without installing a special patch into the ASG.

 

[Rik_CT4s]

I have no idea what Carscanner is logging and whether their conversion values are correct.
Seems like it's torque for rear inverter, but even then the correct values are 610 and 550, not 611 and 551.

You can ask them why they are displaying it incorrectly - I don't use carscanner, but from my short conversation with the author a while back they were empirically searching for values and formulas, so that is not a serious tool, but more of a toy.

I also don't think the total torque was even loggable via $22 on OBD, which CarScanner is using, but you can log front and rear motor torque separately. At least with ODIS or a tool using ODIS dump.
TQEM1 & TQEM2.

I am using factory level datalogging with A2L data, not dealer level, and definitely not toy tool level.
In the A2L the total torque is Elm_tqActSum_VW - but you can never get access to that without installing a special patch into the ASG.

Thank you. Very clear.

Did you use dragy to measure ur 100-200 time post tune on the turbo s CT? That interests me most.

Many thanks. Preparing to take the plunge.

Cheers

 

[prj]

Thank you. Very clear.

Did you use dragy to measure ur 100-200 time post tune on the turbo s CT? That interests me most.

No, but I can if you want.

You want the difference in normal mode 100-200?

Launch control obviously won't be any faster.

 

[Mr.Smith]

How much does battery temperature affect performance?

 

[prj]

How much does battery temperature affect performance?

Haven't really tested, my car is in a warm garage all the time. And then in winter I don't have enough traction for it to matter anyway.

 

[Rik_CT4s]

No, but I can if you want.

You want the difference in normal mode 100-200?

Launch control obviously won't be any faster.

Yes if possible . Tx

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