[stren]

Originally Posted by cstavaru

Unfortunately, the processing speed is not the issue with the piggybacks.

The big issue is that they need to alter things which are not easy to alter because there is no direct or even indirect way to properly alter them. Take the Air-Fuel ratio for example. The (N54) piggybacks truly suck at AFR targeting because there is no easy way to make the ECU change it's AFR target without throwing tuner codes or even other error codes. They use alot of hacks to alter the AFR. That's why you will never see 11.1-11.5 AFR on piggybacks at higher psi but only on flashes. And that is critical to engine safety and longevity.

And there is one other issue: the output signal quality. The piggybacks take the sensor signals (many are linear signals) and output altered signals. The altered signals are not truly linear like the inputs, they are made from digital signals via a digital-to-analog conversion process. Many times, instead of the infinite range of values that an input sensor can give to the ECU, the output signal generated by the piggyback can only have 256 to 1024 separate values in the same range (most of the microcontrollers have 8 to 10-bit DACs or PWMs). So you really lose on signal resolution.

Sure the AFR is a good point. I'm not convinced about the DAC issue though. Presumeably the DME uses a DAC itself to generate the analog signals, as long as the piggy DAC is better than the DME DAC you should be fine right? Does anyone know what the DME/procede/jb3 use?

[cstavaru]

Originally Posted by stren

Sure the AFR is a good point. I'm not convinced about the DAC issue though. Presumeably the DME uses a DAC itself to generate the analog signals, as long as the piggy DAC is better than the DME DAC you should be fine right? Does anyone know what the DME/procede/jb3 use?

You mean the DME uses an ADC to convert sensor signals to digital for further processing, which is right BUT I suppose the ADC of the DME has alot better resolution than 8-10 bits (my guess is at least 16). The JB3 chip is a Microchip PIC18F with 10-bit (1024 values) PWM resolution. The PWMs are used for DAC conversion.

[cstavaru]

Originally Posted by enrita

look at my AFR under channel CAN knock and the boost plus timing, looks pretty ok to me in respect to your comments .

Can't really see from that small 10-20 interval. Do you have some table of values ?

[BrianMN]

Originally Posted by cstavaru

Can't really see from that small 10-20 interval. Do you have some table of values ?

his point is that piggies ARE capable of hitting and DO hit the AFR targets desired.

[cstavaru]

Originally Posted by BrianMN

his point is that piggies ARE capable of hitting and DO hit the AFR targets desired.

I am not sure if the Boost values from that graph are correct, I am not familiar with that logging software but an AFR of 12.5-12 at 19-20psi is not safe. Even BMS admits the fact that the target AFR for that boost should be ~11 (I am not allowed to put links to those discussions here because that site is banned on these forums).

[Mike@N54Tuning.com]

Originally Posted by Clap135

You opinion of 2-3 degrees and 5-6 degrees is just that "your opinion"
Backed by nothing factual.

IMO you are wrong, if you need facts let me know.

We can all agree timing has to be right to maximize power minimize EGT and avoid detonation. That is the purpose of the OEM system. To put timing in the right spot each and every moment dynamically. It's a huge step forward compared to the older static map with set timing retard (KR count) systems many of you have tuned with before.

Whether you are sitting at 2 off maximum or 6 off maximum the DME is doing the same thing. Putting in small amounts of timing of say 1/4 a degree and listening to the knock sensors. Then adding more. Then adding more. Then if knock sensor noise picks up it drops timing down again. This continues perpetually unless you happen to make it to the maximum in which case it stops adding and just listens. But if you're 2 off maximum you can never get there. So the net effect and behaviour is the same whether you are riding the system 2 degrees, 6 degrees, or 26 degrees.

Mike

[enrita]

Originally Posted by cstavaru

Can't really see from that small 10-20 interval. Do you have some table of values ?

look at the value 10.8 next to CANknock on the left

[Mike@N54Tuning.com]

Originally Posted by cstavaru

Unfortunately, the processing speed is not the issue with the piggybacks.

The big issue is that they need to alter things which are not easy to alter because there is no direct or even indirect way to properly alter them. Take the Air-Fuel ratio for example. The (N54) piggybacks truly suck at AFR targeting because there is no easy way to make the ECU change it's AFR target without throwing tuner codes or even other error codes. They use alot of hacks to alter the AFR. That's why you will never see 11.1-11.5 AFR on piggybacks at higher psi but only on flashes. And that is critical to engine safety and longevity.

And there is one other issue: the output signal quality. The piggybacks take the sensor signals (many are linear signals) and output altered signals. The altered signals are not truly linear like the inputs, they are made from digital signals via a digital-to-analog conversion process. Many times, instead of the infinite range of values that an input sensor can give to the ECU, the output signal generated by the piggyback can only have 256 to 1024 separate values in the same range (most of the microcontrollers have 8 to 10-bit DACs or PWMs). So you really lose on signal resolution.

That is all changing. The G4 and PRO boards can now target as rich as 10.0:1 air/fuel ratios at wide open throttle if you (or autotuning) wants.

Mike

[OpenFlash]

Originally Posted by Mike@N54Tuning.com

We can all agree timing has to be right to maximize power minimize EGT and avoid detonation. That is the purpose of the OEM system. To put timing in the right spot each and every moment dynamically. It's a huge step forward compared to the older static map with set timing retard (KR count) systems many of you have tuned with before.

Whether you are sitting at 2 off maximum or 6 off maximum the DME is doing the same thing. Putting in small amounts of timing of say 1/4 a degree and listening to the knock sensors. Then adding more. Then adding more. Then if knock sensor noise picks up it drops timing down again. This continues perpetually unless you happen to make it to the maximum in which case it stops adding and just listens. But if you're 2 off maximum you can never get there. So the net effect and behaviour is the same whether you are riding the system 2 degrees, 6 degrees, or 26 degrees.

Mike

Stop. Either your understanding is limited or you are purposely trying to confuse the masses. Either way, please stop.

[OpenFlash]

Originally Posted by cstavaru

Unfortunately, the processing speed is not the issue with the piggybacks.

The big issue is that they need to alter things which are not easy to alter because there is no direct or even indirect way to properly alter them. Take the Air-Fuel ratio for example. The (N54) piggybacks truly suck at AFR targeting because there is no easy way to make the ECU change it's AFR target without throwing tuner codes or even other error codes. They use alot of hacks to alter the AFR. That's why you will never see 11.1-11.5 AFR on piggybacks at higher psi but only on flashes. And that is critical to engine safety and longevity.

And there is one other issue: the output signal quality. The piggybacks take the sensor signals (many are linear signals) and output altered signals. The altered signals are not truly linear like the inputs, they are made from digital signals via a digital-to-analog conversion process. Many times, instead of the infinite range of values that an input sensor can give to the ECU, the output signal generated by the piggyback can only have 256 to 1024 separate values in the same range (most of the microcontrollers have 8 to 10-bit DACs or PWMs). So you really lose on signal resolution.

The maximum resolution-limited error of the Procede's analog channels is far less than the sensor to sensor variance between cars.

Also, digital signals (like CPS and boost DC) rely on digital voltage thresholds, not analog voltage values. So just as long as the DME sees a triggering edge that is greater than its threshold requirement, it is perfectly happy. So let's not let ill-informed argument get in the way of fact or reason.

Shiv

[BrianMN]

Originally Posted by shiv@vishnu

The maximum resolution-limited error of the Procede's analog channels is far less than the sensor to sensor variance between cars.

Also, digital signals (like CPS and boost DC) rely on digital voltage thresholds, not analog voltage values. So just as long as the DME sees a triggering edge that is greater than its threshold requirement, it is perfectly happy. So let's not let ill-informed argument get in the way of fact or reason.

Shiv

Don't you feel that you're giving up a LOT of useful, proprietary information in this thread? Shoot, if I didn't know better, I'd think vasivalllo was actually Terry trying to get tinfo for making the G4 work right.

[adrian@vishnu]

Hi Guys,

Let me just say that I know a thing or two about the Procede, and a thing or two about engine management in general. I have designed several ECUs using different platforms, and many other tuning devices that were not full ECUs.

Vasillov, it looks to me like you are trying to learn about things which is to be commended, but if you want to learn, you really should refrain from posting your ill-informed opinions until you have the knowledge on which to base them. You are certainly entitled to your opinions, but you come across as ignorant, as almost all the information you are posting as assumptions about piggy-backs is untrue... certainly in the case of the Procede.

For a start, the Procede processor runs at 25MHz. At 6000RPM, the engine turns at 100Hz. There is 60 teeth on the crank position encoder (58 actually as 2 are missing as a reference point). There are a rising and falling edge for each tooth, so lets say 120 edges per revolution. This makes an input frequency of 12kHz. This means that there is OVER 2000 instructions available to the processor per edge of the crank sensor!!. The Procede processor has a high effective vectored interrupt structure. This effectively means that it can respond to an edge in less than 5 instruction cycles. The CPS system is the highest priority interrupt (all other interrupts are nested), and I can assure you that the response of the Procede is far quicker than the jitter in the signal from the sensor.

The analogue signals move FAR slower than the crank sensor. The time constant of the systems that they sense are in the Hz.... not kHz. The Procede passes them through WAY quicker than they need. The Procede uses 10 bit ADC, and 10 bit DAC. This is sufficient to represent all sensors to very high resolution... the boost sensor to 0.03psi. I have worked many years ago on ECUs using 8 bit reolution that had no problems with resolution.

Please also refrain from comparing embedded microcontrollers to x86. The fact is that the much slower embedded micro can do a much better job of engine management that any x86. The reason for this is that the embedded micros have specific peripherals that are designed for doing engine management. The result is that the peripherals do most of the work, and just generate an interrupt when CPU intervention is required. For example with the CPS signal, when an edge occurs, the micro peripheral hardware stores all relevant information about the edge (direction and time it happened) without any CPU intervention, and then generates an interrupt. The CPU can come back several ms later (if desired) and it will still have the exact information it requires. Same goes for CAN. The peripheral is setup to filter the messages that are of interest and add to a queue and flag an interrupt. The CPU can process it when it feels like it. It then adds outgoing messages to another queue, and the peripheral than maintains the queue with no CPU intervention. You would be surprised that the CPU itself does very little... it is the peripherals that do all the work, and they are all independant parallel running processors that have only one job in life and they do it very well.... much better than any x86 based processor that would have to poll all inputs.

Finally, as Shiv has stated.... with previous piggybacks (pre CAN logging) we used to have to "guess" what the DME did. When I say guess, I mean we observed what the DME did and then programmed the behaviour into the software. The JB3 still does this... this is how they determine the DME boost target which is so important on this platform. Since CAN we nolonger have to guess. We just get the DME to tell us what it is doing. It is no secret that Procede made a leap forward in tuning when we integrated the CAN logging. All of our algorithms for predicting DME responses were removed. Now we just read the response direct from the DME. We know what boost it is targetting based upon all its internal algorithms including DTC. We can base internal Procede algorthms on this to know when DTC is in operation (and many other things). The CAN logging removed many of the shortcomings of a piggy-back.

Finally a comment on Flash tuning. Flash tuning has its own benefits. In the case that the flash programmers have enough knowledge, it would be the best solution. Unfortunately this is not the case on this platform. In my observation, the flash tuners can only retune the tables BMW programmed. The problem is that the algorthms themselves are hardcoded, and they are not always optimised for the requirements of higher boost levels (witness the boost oscillations most flashes experience at higher boost levels). Until the flash tunes can rewrite the algorithms and write new ones (like meth support etc), I think the piggybacks will have the edge. They can do 99% as gooder job as a flash with the tuning, but can add their own algorithms and respond very quickly in terms of adding features. Piggy-backs have the edge on new markets that take the flash tunes years to crack. Often by the time they have good results, the market has moved on... witness the new DME in the N55 engine which will now need to be cracked like the old. With a quality piggyback, we can do a great job of the tune, and we can get all features to market much quicker... often years quicker. Who would have predicted that the most advanced tune for the N54 would still be the Procede... almost 4 years on!!

Cheers,

Adrian

[MarkD]

Originally Posted by BrianMN

Don't you feel that you're giving up a LOT of useful, proprietary information in this thread? Shoot, if I didn't know better, I'd think vasivalllo was actually Terry trying to get tinfo for making the G4 work right.

I haven't seen any secrets given out in this thread yet.

[Ilma]

Originally Posted by Mike@N54Tuning.com

Whether you are sitting at 2 off maximum or 6 off maximum the DME is doing the same thing. Putting in small amounts of timing of say 1/4 a degree and listening to the knock sensors. Then adding more. Then adding more. Then if knock sensor noise picks up it drops timing down again. This continues perpetually unless you happen to make it to the maximum in which case it stops adding and just listens. But if you're 2 off maximum you can never get there. So the net effect and behaviour is the same whether you are riding the system 2 degrees, 6 degrees, or 26 degrees.

Mike

Go back and explain this in the context of the logs I posted earlier.

With knock at the top of 3rd gear, my timing dropped 3 degrees and the subsequent timing entering into 4th gear was around 4.5 degrees.

By introducing 1 degree of offset, and avoiding the knock event in 3rd....my subsequent timing entering into 4th gear was 7.5 degrees.

So do the math.....by reducing 1 degree earlier in the power curve, I ended up 3 degrees higher at the end.

How is that the same?

[cn555ic]

Many spies and comrades collectively looking for info and secrets for their leader! Too many Bond movies for me! lol

[Mike@N54Tuning.com]

Originally Posted by cn555ic

Many spies and comrades collectively looking for info and secrets for their leader! Too many Bond movies for me! lol

Please don't take this the wrong way but you and a few others with your mindset and bias really have no idea what you're talking about in this respect. There is absolutely nothing in this or any other discussion thread that would be useful to someone designing a piggyback system or trying to copy another piggyback system. If someone was interested in copying they would need only the box itself to measure the inputs and outputs. That information would only be useful if the system they were designing was similar enough that those inputs and outputs could be reimplemented. BMS and Vishnu have never had common hardware platforms. Vishnu's internal algorithms are not relevant to BMS and vice versa. Both are useless to CPE, GIAC, etc.

Mike

[shifterboy45]

i think this whole thread is in danger for being de-railed by personal preferences.

without siding for one or the other -- the idea of signal interception and manipulation is totally inferior to the a hardware based logic system is kind of old. in earlier days of the technology, it was limited a few simplistic processing tasks -- but i think we are a long way from that point today.

granted i believe that the hardware based control logic is the purist way to tune, but does that take away from the advances to a signal interceptor which is fed by a bus system I/O's and translates these into usable (and adjustable) variables for proper operation? as long as proper tuning etiquitte is foremost in the equation, there is little to dispute.

this is not a biased opinion, it just like disputing if my current laptop has the computing power of a my CTX laptop in 1995 -- things have changed -- alot

[phazedkid]

Originally Posted by Mike@N54Tuning.com

Please don't take this the wrong way ... Both are useless to CPE, GIAC, etc.
Mike

cool.

now, please answer this question from Ilma. I'm here to learn from the technical debate and have enjoyed it so far. thanks.

Originally Posted by Ilma

Go back and explain this in the context of the logs I posted earlier.

With knock at the top of 3rd gear, my timing dropped 3 degrees and the subsequent timing entering into 4th gear was around 4.5 degrees.

By introducing 1 degree of offset, and avoiding the knock event in 3rd....my subsequent timing entering into 4th gear was 7.5 degrees.

So do the math.....by reducing 1 degree earlier in the power curve, I ended up 3 degrees higher at the end.

How is that the same?

[Clap135]

Originally Posted by Mike@N54Tuning.com

We can all agree timing has to be right to maximize power minimize EGT and avoid detonation. That is the purpose of the OEM system. To put timing in the right spot each and every moment dynamically. It's a huge step forward compared to the older static map with set timing retard (KR count) systems many of you have tuned with before.

Whether you are sitting at 2 off maximum or 6 off maximum the DME is doing the same thing. Putting in small amounts of timing of say 1/4 a degree and listening to the knock sensors. Then adding more. Then adding more. Then if knock sensor noise picks up it drops timing down again. This continues perpetually unless you happen to make it to the maximum in which case it stops adding and just listens. But if you're 2 off maximum you can never get there. So the net effect and behaviour is the same whether you are riding the system 2 degrees, 6 degrees, or 26 degrees.

Mike

knock is not knock, there are different 'levels' of knock. Knocking because timing is off by 1-2 degrees and knocking because timing is off by 5 degrees is alot different. If i were terry I would put a halt to your posts because you are making it look even worse

[Sniz]

Originally Posted by Clap135

knock is not knock, there are different 'levels' of knock. Knocking because timing is off by 1-2 degrees and knocking because timing is off by 5 degrees is alot different. If i were terry I would put a halt to your posts because you are making it look even worse

Clap


Terry probably wrote that post

[OpenFlash]

Originally Posted by Clap135

Are you dense?
knock is not knock, there are different 'levels' of knock. Knocking because timing is off by 1-2 degrees and knocking because timing is off by 5 degrees is alot different. If i were terry I would put a halt to your posts because you are making it look even worse

The scary part is that it's Terry, not Mike, posting this nonsense. At this point, I'm guessing Mike just holds his breathe and crosses his fingers when Terry gives him something to post.

[Clap135]

Originally Posted by Sniz

Clap


Terry probably wrote that post

No that was all mike, Terry isnt that stupid.

And if that post was actually posted by Terry, then may god help all the jb3 users out there cause that was biggest case of BULLSHIT I have ever heard.