Part 2: The J1 Powertrain

[Rik_CT4s]

I am working on the temp website and the descriptions.
I do a few things other than giving the real full launch power & torque all the time. The antisurge damper (torque filter) is recalibrated to disengage when the powertrain is pretensioned and there's a sharp throttle movement giving much better throttle response during dynamic driving, the shiftpoints are optimized to deliver the maximum power better in all modes, the top speed limitation is removed, only the motor rpm limiter remains, and few other bits...

If your car is not tuned yet, then I'd say it's a nobrainer. Certainly the difference is big in normal driving.
The theoretical launch control is all well and good, but 99% of the time it is just that - theoretical. Together with the other modifications the car goes from being fast to brutal snap power delivery when you want it, yet drives exactly like stock when you don't.

But of course I am selling this stuff. So one of you will have to take the plunge.
If you're not happy with it - send it back and I'll give you a refund. I don't think I will ever have to do that, but maybe that gives some peace of mind


The ASG constantly records this information in the background, but yeah they don't send that online ... yet. Only when warranty work needs to be performed they have to do a check, and only at that moment the information is communicated.

That said, I am sure in the future this will go online (on new platforms). BMW already do that. Tune the car and your warranty is gone before you can blink.

Very clear, thank you.
So in case for the Turbo S, 800ps / 1050Nm all the time / any time?
or it drops also along with the declining SOC during drives. Perhaps there is a threshold from where that power cannot be drawn anymore.
Well, let's wait for part 3 as you will be asked many questions and we want you to save some time for developing the awesome stuff you are doing.

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[bn8959]

The ASG constantly records this information in the background, but yeah they don't send that online ... yet. Only when warranty work needs to be performed they have to do a check, and only at that moment the information is communicated.

That said, I am sure in the future this will go online (on new platforms). BMW already do that. Tune the car and your warranty is gone before you can blink.

Makes sense. Presumably this isnt something they could just 'turn on' remotly - they would need to physically update other software to enable this reporting. If you are swapping back the ASG, then the logs from the modified one wouldnt be available to them. I guess the only issue could be if they detect a 'lack' of logs, or missing activity on the ASG (eg perhaps it records power-on-time, which would be suspiciously low compared to all other car components), then they could use that as a reason to initiate a TD1 flag.

I think the confidence I'd need to do this mod, would be to know that there is low risk of future warranty denial- and that there isnt a significant risk of it being retrospectively picked up (eg if logs are constantly reported, but not currently actioned, but could be later, then this is a problem - it would mean then even if you ran a modified ASG, then changed your mind - the history could be there for a future TD1 flagging). If we hear about new updates being installed during warranty work/servicing etc - then subsequently hear of warranty denials - if we can then revert back to the original ASG and still maintain a low(ish) risk of being ok - then, it certainly does become a no-brainer in my mind!

 

[prj]

Very clear, thank you.
So in case for the Turbo S, 800ps / 1050Nm all the time / any time?
or it drops also along with the declining SOC during drives. Perhaps there is a threshold from where that power cannot be drawn anymore.

Yes, of course it declines.
800 PS is only available at 100%.
At 95% you have 790 PS.
At 85% you have the Porsche quoted 761 PS.
At 75% You have 730 PS.
But of course all that is higher than 625 PS, and you still get the extra torque all the time.

Makes sense. Presumably this isnt something they could just 'turn on' remotly - they would need to physically update other software to enable this reporting.

I think it'd be incredibly difficult to do remotely and also their backend doesn't support anything like that.
Doing the development for older cars would be not worth the time spent, I think the likelihood is extremely low.

If you are swapping back the ASG, then the logs from the modified one wouldnt be available to them. I guess the only issue could be if they detect a 'lack' of logs, or missing activity on the ASG (eg perhaps it records power-on-time, which would be suspiciously low compared to all other car components), then they could use that as a reason to initiate a TD1 flag.

No, that's not how TD1 works at all. I will write more in Part 3, but TD1 is basically triggered by unsigned download to the ECU. That's the only thing that is checked, nothing else. No unsigned download to ECU, no TD1.
Operating hours and so on - all that is not important and not checked.

I think the confidence I'd need to do this mod, would be to know that there is low risk of future warranty denial

I think practically the risk is extremely low. Theoretically of course it is possible, but they haven't really changed the TD1 mechanism that much since 2005 or so. The only thing that has changed is that they moved it into the HSM on the newer ECU's, but the mode of operation is the same.

 

[Rik_CT4s]

Yes, of course it declines.
800 PS is only available at 100%.
At 95% you have 790 PS.
At 85% you have the Porsche quoted 761 PS.
At 75% You have 730 PS.
But of course all that is higher than 625 PS, and you still get the extra torque all the time.


I think it'd be incredibly difficult to do remotely and also their backend doesn't support anything like that.
Doing the development for older cars would be not worth the time spent, I think the likelihood is extremely low.


No, that's not how TD1 works at all. I will write more in Part 3, but TD1 is basically triggered by unsigned download to the ECU. That's the only thing that is checked, nothing else. No unsigned download to ECU, no TD1.
Operating hours and so on - all that is not important and not checked.


I think practically the risk is extremely low. Theoretically of course it is possible, but they haven't really changed the TD1 mechanism that much since 2005 or so. The only thing that has changed is that they moved it into the HSM on the newer ECU's, but the mode of operation is the same.

So Torque in case of the TS is always 1050Nm at any given time? Until a certain threshold perhaps.
If so, that would be noticeable for sure. Especially during in between acceleratio .
Any idea what topspeed to expect on the TS without the limiter as the current factory settings are not impressive.

 

[prj]

So Torque in case of the TS is always 1050Nm at any given time?

Correct, refer to the powertrain torque curve, and correct the first gear for RPM
But basically in first gear from 0-50km/h you have 1050 Nm yes, no matter what.

If so, that would be noticeable for sure. Especially during in between acceleratio .

Absolutely.

Any idea what topspeed to expect on the TS without the limiter as the current factory settings are not impressive.

Around 270km/h, after that you hit the motor rpm limiter. The dash shows more than that.

I haven't tested the exact number, but I'll put my Turbo S on the dyno tomorrow again and check for the exact number. Got the summer tyres on today, so I can go to that speed safely (blowing a tyre on the dyno at Vmax = half of the rear of the car gone. Very dangerous).

 

[Mr.Smith]

In theory, Is there a way for the dealer or to create a software to block the TD1 check?

 

[Rik_CT4s]

In theory, Is there a way for the dealer or to create a software to block the TD1 check?

That would immediate tricker a TD1 I guess....

 

[prj]

In theory, Is there a way for the dealer or to create a software to block the TD1 check?

You can make the ECU not answer anything to the check. If anyone ever checks that by hand you will get immediate TD1, that's the case with Audi at least with the high end performance cars with e.g. engine damage.

You can't actually fake the check or alter it, because it's done in the HSM, and even if you can flash the main part of the processor through an exploit, you still don't have access to the HSM.

As I said before - right now Audi and Porsche don't take any action on the backend even if a tuned ASG is detected. This could stay like this forever, or they could start voiding warranties next week. You never know. So I don't take any chances.

In USA it's safer to modify the existing unit because of the legal framework, as the manufacturer has to prove beyond reasonable doubt that the failure has been caused by the modification if they want to refuse warranty. Since the ASG modification can not cause a failure, this is impossible to prove, and modification of the ASG alone isn't grounds for warranty refusal in the US. However, you can be fighting an uphill battle there, because Porsche definitely has more money than you.
Furthermore, they can still refuse to e.g. extend your Porsche Approved warranty and similar shenanigans.

In the rest of the world though, they can void your warranty if they want to, and there's nothing you're going to do about it, because they have proof that the controller was modified.

Basically my suggestion - don't mess with the warranty on a Taycan and don't own one without warranty.

 

[freeforall]

Very informative post, thank you!

5.5. Taycan RWD - Either battery type

The RWD Taycan manages 480 PS and 340 Nm outside launch control and 480 PS and 360 Nm with launch control.

Interesting… so basically RWD ECU tune is just about making available the 480 PS already available in LC and, from a torque perspective there is no increase possible.
So the +15%/20% horse power increase on top of the 480 PS promised by folks like redshift is complete BS?

 

[ze_shark]

1. If you read the post you will notice, that the torque is not (and can not be) significantly increased. So I do not understand the 600Nm vs 1050Nm comparison, as this can never ever happen. The 4S can never make 1050 Nm of torque, the maximum it can do is 660Nm.

2. In material science there are different thresholds of failure. Basically, as long as you are under the failure threshold it makes little difference if the torque is 50 Nm or 1000Nm.

3. Everything that concerns the power transmission is pretty much identical between even a 4S and Turbo S.

None of the cars (except the Taycan 4, but it's really a detuned 4S) gain more than 10% over their rated torque. The power increases substantially, yes, but power does not break stuff, torque does.

By your common sense theory, the cheapest model, the Taycan RWD would be the most likely to break, as it's running closest to the component limits from the factory out of all the cars. Does not really make much sense, does it?

Sorry, I had misunderstood that. I thought the upside on a 4S was far greater. Maybe it is different on J1.2.

I disagree with your point though: the car is dimensioned for 1050 Nm plus whatever safety factor Porsche engineers apply. Warranty failures come from parts not meeting the spec yet escaping QC. Otherwise you live in a zero escape utopia. The probability of such failures increases with torque.

Another element: if all there is on tap is a 10% torque increase which i can have on tap with push-to-pass for a long enough time, why spend 2500 EUR and risk warranty ? That is a personal risk reward assessment. I can feel torque but i cannot feel power so i care less about it for a road car.

 

[prj]

Another element: if all there is on tap is a 10% torque increase

There is a PEAK torque increase of 5-10% at low speeds.
However, the Taycan 4S at e.g. 85kph has 50% more torque and 50% more horsepower than stock in normal mode.

which i can have on tap with push-to-pass for a long enough time

Push to pass does not exist on J1.1. Furthermore the push to pass power increase is much less than the total possible on e.g. the Taycan 4S PB+.

why spend 2500 EUR

To have 50% more power. And go from 9.1s 100-200 in launch control to 6.6s in any mode.

and risk warranty ?

There is no warranty risk with a replacement controller.

I can feel torque but i cannot feel power so i care less about it for a road car.

Looking at only peak torque is well... peak ignorance, sorry.
No one is making you buy anything - if you don't need more power and are happy as-is, that's great. The majority of people in the world feel the same way.
But please do not make false statements. You can absolutely feel a 50% bump in the torque curve on a 4S, the performance isn't even close.
And on the Turbo S the 100Nm extra peak is very noticeable as well. Plus the reduced throttle delay during large load changes...

Interesting… so basically RWD ECU tune is just about making available the 480 PS already available in LC

Correct. Of course the gain on the car without the PB+ is somewhat larger as it's more detuned from the factory.

and, from a torque perspective there is no increase possible.

With my special patch, it is possible to have 360Nm instead of 340Nm in normal mode. But yeah, the peak torque increase is miniscule.

So the +15%/20% horse power increase on top of the 480 PS promised by folks like redshift is complete BS?

Yes, it is.
Just the same as promising 1050Nm on the Taycan Turbo or 850Nm on the Taycan 4S is complete BS.
The inverters have hard limits, and no matter what you do with the ASG you can not exceed those. And nobody is flashing the inverters (which I also wouldn't advise you to, as that's the best way to start blowing stuff up).

You can see in this thread the maximum possible performance diagrams for every model. If anyone says you can get more with an ASG tune, they either don't know any better or are lying to you to solicit more sales, it's as simple as that.

These fake number shenanigans going on for years is in large the reason I have posted all this information out here. I strongly dislike it.

 

[prj]

As promised, today I put the car on my dyno again:

Then I put it in Dyno mode and ran it, which according to some companies is "impossible":

And I tested the max speed limit. I got 269 km/h indicated on the dash with 21" wheels and the OEM fitment tyres (with modified ASG of course!):

At that point the car had 16000 RPM on the rear motor and was bouncing off the limiter, and 15500 RPM on the front motor:

The link between the front and rear on the dyno was engaged. I didn't want to do any funny stuff like letting the front wheels spin faster than the rears.

I didn't do any power runs because with 56% SoC that's pretty pointless (you can see already in the screenshot the limitation was 523 kW from the battery, so probaby around 460 kW output power). But if someone wants to see the most boring dyno graph in the world with a diagonal torque line and flat power line, then I can do that when I charge the car to 100%.

The ASG is much more precise though than the dyno can measure, because when you do the coastdown measurement then the regen shenanigans really mess stuff up and you end up with inflated power figures.

Btw, considering the ASG was showing like 260.5km/h and the stock vmax in the ASG is 260km/h on the Turbo S, then it's possible that this car will also run this speed with stock ASG. The e-tron GT for example is 231 km/h in the ASG.

 

[BjörnfromHamburg]

Nice CT you have there...very little km, you don't drive it much ?

 

[prj]

Nice CT you have there...very little km, you don't drive it much ?

Thanks. I bought in January with the goal to develop the tuning for the J1 platform.
This is just what I do...

 

[ATCO]

Really appreciate the SoC-based power caps you posted (800 → 790 → 761 → 730 PS). Could you share the rest of the table—ideally every 5 % or 10 % down to the “turtle” zone—so we can see the full profile?


I’m also curious about how temperature is built into the limiter. In my experience on a stock car the power is limited more severely at lower battery temperatures, probably at higher but haven't tested that.

That makes me think the control is a 2D map or maybe a pair of 1-D lookups with the lower of the two caps winning.

Any chance you can confirm how the map is structured—or better, share typical power ceilings at, say, 15 °C / 25 °C / 35 °C for a few SoC points?

Obviously it is not relevant to the tune, I'm more interested in how the BMS works and what are the limits since with higher power we'll hit those ceilings sooner.

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