[jpsimon]

and just throwing this out there, that 1st - 3rd was going up a decently steep on-ramp.

[Ilma]

Originally Posted by Mike@N54Tuning.com

Your newest log brings up an interesting point for analysis. Check out how timing drops each gear,

So does that mean your car is ridiculously knocking in 4th gear? (spoiler alert: it doesn't, but curious for your analysis).

Mike

Timing drops between gears with JB3 also.


[IMG][/IMG]

[Soni]

[bren335i]

Originally Posted by Mike@N54Tuning.com

By 4th gear timing is almost to the floor, yet a 4th gear dyno pull like the ones posted in my thread show much higher values. IAT isn't logged here but with your intercooler we're probably looking at a ~30F rise over the run? Not enough to trigger more CPS offsetting per the V3 tuning.

So does that mean your car is ridiculously knocking in 4th gear? (spoiler alert: it doesn't, but curious for your analysis).

Mike

You really are "new" to this whole "tuning" thing, huh?

May want to run that one by Terry before you hit "send."

[Mike@N54Tuning.com]

Originally Posted by shiv@vishnu

Mike,
The DME trims timing based up IAT, gear and rate of acceleration. Not just knock activity. And contribution of knock activity can be isolated by retesting that same run on race gas.

Shiv

Shiv,

I believe you've tuned the V3 to reduce boost and increase CPS offsetting as a function of IAT. There is no sign of boost reduction or CPS increase during the run. These timing values look nothing like the timing values we've seen in the same or higher gear pulls on the dyno. The only mechanism left to adjust timing to this extreme degree is knock sensor feedback. In this case, it looks like its relying on it heavily. I'm not suggesting that is a bad thing, but I think the data is there to support it.

Mike

[Mike@N54Tuning.com]

Originally Posted by Ilma

Timing drops between gears with JB3 also.

I would certainly hope so! And your logs clearly show its not through IAT. The biggest contributor stock and tuned, CPS or not, is load sensing through knock sensor feedback. Otherwise we'd always see similarly low timing numbers during same gear pulls on the dyno.

Mike

[lawdude]

Originally Posted by Mike@N54Tuning.com

I wasn't even a sponsor a year ago, so I am not sure what nonsense I was up to then.

No need to search; you're posting it now.

[Ilma]

Originally Posted by Mike@N54Tuning.com

"I would certainly hope so! And your logs clearly show its not through IAT. The biggest contributor stock and tuned, CPS or not, is load sensing through knock sensor feedback. Otherwise we'd always see similarly low timing numbers during same gear pulls on the dyno."

+

"The only mechanism left to adjust timing to this extreme degree is knock sensor feedback"

Mike

I notice this pattern on my logs too.

In multiple 2nd to 4th gear pulls, the timing drops for each successive gear change.

But if I do a single gear pull starting in 3rd, the timing advance stays at the same level as 2nd gear did in the multiple gear pull.

Load is identical in 3rd gear either way, so you are concluding that knock is solely responsible for the timing drop?

If so, then why would timing advance be higher for 3rd on the single gear pull than it is on the multiple gear pull?

[MNR0]

Can Procede or JB3 intercept and nullify any knock events? Like moderate or remove any knock induced timing?

I wouldn't be so sure that is real knock - rather false knock or just predictive retard

[scalbert]

Originally Posted by Mike@N54Tuning.com

Shiv,

I believe you've tuned the V3 to reduce boost and increase CPS offsetting as a function of IAT. There is no sign of boost reduction or CPS increase during the run. These timing values look nothing like the timing values we've seen in the same or higher gear pulls on the dyno. The only mechanism left to adjust timing to this extreme degree is knock sensor feedback. In this case, it looks like its relying on it heavily. I'm not suggesting that is a bad thing, but I think the data is there to support it.

And how do you know there is no additional CPS correction? This is the Integer value, there is a Floating Point value that was not logged as well as not having IAT shown. So once again we are shooting in the dark.

And BTW, you left out another critical value that the DME has. As a hint, it is the most precise thing we can measure in nature; Time. I would expect the DME measures loaded time as well as all the other parameters. So that ignition advance will be reduced as the time under load increases. Granted, this is just a hypothesis but seems reasonable and definitely debunks the notion that the only thing left to measure is knock.

[Ilma]

Originally Posted by shiv@vishnu

Mike,
The DME trims timing based up IAT, gear and rate of acceleration. Not just knock activity.

Shiv

Hmmmmm

Rate of acceleration would explain my earlier question as to why timing stays higher on a single gear pull.....the rate of acceleration is obviously slower when you start in a higher gear at low rpm.....like for a FATS run or dyno run.

[adrian@vishnu]

Hi All,

I just wanted to make the point that rate of acceleration makes a big difference to the tune. If you tune a speed density system (map sensor tuned) system for fuel mixtures at low rate of acceleration or zero rate of acceleration (loaded on a dyno), and then log the mixtures at faster rates of acceleration, it will run up to 0.5AFR leaner in low gears. This is normal, and a result of everything playing catchup with the engine. The thing with engines, is that the engine itself is effected by the throttle, but everything else is reponding to the engine, and there are different time delays involved for different things to respond which result in many things lagging different amount of time behind the actual engine conditions:

* Turbo shaft speed needs to accelerate with engine RPM. Especially with larger turbos, you generally find it can lag behind and as a result you get lower boost in lower gears. You can do things in terms of boost control algorithms to get the turbo up to boost, but this results in the wastegates being closed more at a specific boost and RPM at fast engine acceleration then at slow acceleration as it takes more energy to accelerate a turbo than keep it at the same speed. Wastegates effect exhaust back pressure which effects tune (and ignition timing).

* VANOS takes finite time to reach target position, and will lag behind the engine RPM. So it may have the optimal setting for 4000RPM when the engine has now reach 5000RPM. This also ignores the fact that BMW have probably tuned the VANOS to optimise turbo spool, and they may run different VANOS target positions for different rate of acceleration. You can bet on the fact that the target ignition timing is dependant on the VANOS position.

* There are thermal things also... EGTs will be higher after sustained load. This will help turbo spool better, but will also cause the ECU to change aspects of the tune to control EGTs.

The things is that ignition timing can respond much quicker than these other things. Therefore the ECU can alter the ignition timing to the actual current engine condition within a fraction of the time of one cylinder event, but these other things lagging are many cylinder events behind.

So my point is that Mike's assumption that different timing in different gears provides evidence that the ECU is "riding" the knock sensor is just that... an assumption. IMHO this is not the case (and I am also making an assumption), and it is just the ECU having a different set of inputs it is dealing with at higher acceleration rates, and as a result it runs different outputs... like different target ignition timing.

This "discussion" is one that no side will ever concede defeat. I think the users/buyers just have to decide which they are happier with. My take on it is that JB cannot offer certain features (I do not believe for a moment that they had it and decided it was not beneficial), so they have presented a reasoning for why these features are not required (and I do believe they have acted underhanded in thier reasoning by presenting false information that they hoped would not be found out). The reason they cannot offer these features is because they operate on cheaper hardware and as a result thier product is cheaper.

The Procede has used historically proven techniques, but it costs more to do this. Therefore the product is more expensive. The problem is that Vishnu have a more advanced and expensive product, so in order to leverage off the extra features, they need the market to be aware of the benefits. If the market sees that the JB and Procede do the same thing, but the JB is cheaper, what will the market buy. That is how this "discussion" started. Vishnu could have chosen to remove features and reduce cost, but they honestly believe that these features are beneficial to optimise the tune, so they are defending this position.

When all is said and done, there is nothing technically that the JB can do that the Procede cannot, but there are several things that the Procede can do that the JB cannot. Some things cannot be outright proven. Even if the evidence does seem to support it, the opposition can find some evidence to support their own argument. So the end user has to weigh up the difference in cost, and decide if the extra cost is worth the risk reduction of engine unreliabiilty/failure and other features for their requirements.

With respect to this "discussion".... CPS offsetting would not take anything away from a tune. The argument is whether it adds anything. So even if CPS does not add anything, does this make the JB a better tune... or just equal? And what if it does have a positive effect?

[Sniz]

Originally Posted by adrian@vishnu

Hi All,

I just wanted to make the point that rate of acceleration makes a big difference to the tune. If you tune a speed density system (map sensor tuned) system for fuel mixtures at low rate of acceleration or zero rate of acceleration (loaded on a dyno), and then log the mixtures at faster rates of acceleration, it will run up to 0.5AFR leaner in low gears. This is normal, and a result of everything playing catchup with the engine. The thing with engines, is that the engine itself is effected by the throttle, but everything else is reponding to the engine, and there are different time delays involved for different things to respond which result in many things lagging different amount of time behind the actual engine conditions:

* Turbo shaft speed needs to accelerate with engine RPM. Especially with larger turbos, you generally find it can lag behind and as a result you get lower boost in lower gears. You can do things in terms of boost control algorithms to get the turbo up to boost, but this results in the wastegates being closed more at a specific boost and RPM at fast engine acceleration then at slow acceleration as it takes more energy to accelerate a turbo than keep it at the same speed. Wastegates effect exhaust back pressure which effects tune (and ignition timing).

* VANOS takes finite time to reach target position, and will lag behind the engine RPM. So it may have the optimal setting for 4000RPM when the engine has now reach 5000RPM. This also ignores the fact that BMW have probably tuned the VANOS to optimise turbo spool, and they may run different VANOS target positions for different rate of acceleration. You can bet on the fact that the target ignition timing is dependant on the VANOS position.

* There are thermal things also... EGTs will be higher after sustained load. This will help turbo spool better, but will also cause the ECU to change aspects of the tune to control EGTs.

The things is that ignition timing can respond much quicker than these other things. Therefore the ECU can alter the ignition timing to the actual current engine condition within a fraction of the time of one cylinder event, but these other things lagging are many cylinder events behind.

So my point is that Mike's assumption that different timing in different gears provides evidence that the ECU is "riding" the knock sensor is just that... an assumption. IMHO this is not the case (and I am also making an assumption), and it is just the ECU having a different set of inputs it is dealing with at higher acceleration rates, and as a result it runs different outputs... like different target ignition timing.

This "discussion" is one that no side will ever concede defeat. I think the users/buyers just have to decide which they are happier with. My take on it is that JB cannot offer certain features (I do not believe for a moment that they had it and decided it was not beneficial), so they have presented a reasoning for why these features are not required (and I do believe they have acted underhanded in thier reasoning by presenting false information that they hoped would not be found out). The reason they cannot offer these features is because they operate on cheaper hardware and as a result thier product is cheaper.

The Procede has used historically proven techniques, but it costs more to do this. Therefore the product is more expensive. The problem is that Vishnu have a more advanced and expensive product, so in order to leverage off the extra features, they need the market to be aware of the benefits. If the market sees that the JB and Procede do the same thing, but the JB is cheaper, what will the market buy. That is how this "discussion" started. Vishnu could have chosen to remove features and reduce cost, but they honestly believe that these features are beneficial to optimise the tune, so they are defending this position.

When all is said and done, there is nothing technically that the JB can do that the Procede cannot, but there are several things that the Procede can do that the JB cannot. Some things cannot be outright proven. Even if the evidence does seem to support it, the opposition can find some evidence to support their own argument. So the end user has to weigh up the difference in cost, and decide if the extra cost is worth the risk reduction of engine unreliabiilty/failure and other features for their requirements.

With respect to this "discussion".... CPS offsetting would not take anything away from a tune. The argument is whether it adds anything. So even if CPS does not add anything, does this make the JB a better tune... or just equal? And what if it does have a positive effect?

[jpsimon]

I always enjoy reading your posts Adrian! Thanks for your input

[TheTwinz]

Originally Posted by adrian@vishnu

The Procede has used historically proven techniques, but it costs more to do this. Therefore the product is more expensive. The problem is that Vishnu have a more advanced and expensive product, so in order to leverage off the extra features, they need the market to be aware of the benefits. If the market sees that the JB and Procede do the same thing, but the JB is cheaper, what will the market buy. That is how this "discussion" started. Vishnu could have chosen to remove features and reduce cost, but they honestly believe that these features are beneficial to optimise the tune, so they are defending this position.

When all is said and done, there is nothing technically that the JB can do that the Procede cannot, but there are several things that the Procede can do that the JB cannot. Some things cannot be outright proven. Even if the evidence does seem to support it, the opposition can find some evidence to support their own argument. So the end user has to weigh up the difference in cost, and decide if the extra cost is worth the risk reduction of engine unreliabiilty/failure and other features for their requirements.

With respect to this "discussion".... CPS offsetting would not take anything away from a tune. The argument is whether it adds anything. So even if CPS does not add anything, does this make the JB a better tune... or just equal? And what if it does have a positive effect?

I agree with this post 100%! Adrian should be the spokesperson for Vishnus company. Adrian clearly states the fact and respects that he too isn't sure whether or not CPS adds anything. He doesn't belittle anyone, nor try to scare people into thinking that the JB3 is going to blow up your engine.

And you are right, there are tons of things the Procede can do that JB can't, and a lot of the things it can do might not necessarily apply to the N54. We all have to remember that the Procede is a universal application meaning it works on a ton of different cars. That is why it is more advanced and has more features, and safety measures for all varieties of cars. I'm still debating whether or not this whole timing debacle is really as bad as Shiv would like the public to think it is.

[OpenFlash]

Originally Posted by TheTwinz

I agree with this post 100%! Adrian should be the spokesperson for Vishnus company. Adrian clearly states the fact and respects that he too isn't sure whether or not CPS adds anything. He doesn't belittle anyone, nor try to scare people into thinking that the JB3 is going to blow up your engine.

And you are right, there are tons of things the Procede can do that JB can't, and a lot of the things it can do might not necessarily apply to the N54. We all have to remember that the Procede is a universal application meaning it works on a ton of different cars. That is why it is more advanced and has more features, and safety measures for all varieties of cars. I'm still debating whether or not this whole timing debacle is really as bad as Shiv would like the public to think it is.

Did u read the same post I did?

Shiv

[brianhn1]

Need some clarifications:

Originally Posted by adrian@vishnu

Hi All,

I just wanted to make the point that rate of acceleration makes a big difference to the tune. If you tune a speed density system (map sensor tuned) system for fuel mixtures at low rate of acceleration or zero rate of acceleration (loaded on a dyno), and then log the mixtures at faster rates of acceleration, it will run up to 0.5AFR leaner in low gears. This is normal, and a result of everything playing catchup with the engine.

Are you referring to user defined torque requested?

The thing with engines, is that the engine itself is effected by the throttle, but everything else is reponding to the engine, and there are different time delays involved for different things to respond which result in many things lagging different amount of time behind the actual engine conditions:

* Turbo shaft speed needs to accelerate with engine RPM. Especially with larger turbos, you generally find it can lag behind and as a result you get lower boost in lower gears. You can do things in terms of boost control algorithms to get the turbo up to boost, but this results in the wastegates being closed more at a specific boost and RPM at fast engine acceleration then at slow acceleration as it takes more energy to accelerate a turbo than keep it at the same speed. Wastegates effect exhaust back pressure which effects tune (and ignition timing).

You mean turbo shaft speed has to increase with engine RPM? Engine torque demand will directly correlate with turbo shaft rotational acceleration during the spool phase.

BMW chose to use small turbos because of their low moment of inertia. Turbo lag is not a huge issue in the N54 application.

* VANOS takes finite time to reach target position, and will lag behind the engine RPM. So it may have the optimal setting for 4000RPM when the engine has now reach 5000RPM. This also ignores the fact that BMW have probably tuned the VANOS to optimise turbo spool, and they may run different VANOS target positions for different rate of acceleration. You can bet on the fact that the target ignition timing is dependant on the VANOS position.

VANOS is used to advance the intake and exhaust camshaft timings depending on the engine speed and torque demanded. It does not take a finite time, as distance to advance depends on starting and final cam timing.

How do you know that ignition timing is dependent on double VANOS positioning?

* There are thermal things also... EGTs will be higher after sustained load. This will help turbo spool better, but will also cause the ECU to change aspects of the tune to control EGTs.

ECU will change certain parameters to control EGTs depending on condition states such as cold start, normal engine oil/water temperature levels, cruise with depressed catalyst converter temps. To increase, either lean the mixture or retard timing. However, the engine retarding timing reactively under high torque demand situations does not mean it is because of low EGTs.

The things is that ignition timing can respond much quicker than these other things. Therefore the ECU can alter the ignition timing to the actual current engine condition within a fraction of the time of one cylinder event, but these other things lagging are many cylinder events behind.

Ignition timing is reactive towards input parameters and the engine operating state.

So my point is that Mike's assumption that different timing in different gears provides evidence that the ECU is "riding" the knock sensor is just that... an assumption. IMHO this is not the case (and I am also making an assumption), and it is just the ECU having a different set of inputs it is dealing with at higher acceleration rates, and as a result it runs different outputs... like different target ignition timing.

The ECU seems to have lots of inputs it relies upon to determine ignition timing.
If the ECU has so many inputs, then how it is able to refer to hundreds or possibly thousands or even tens of thousands of "tables"? ECU is clearly no supercomputer...but acts like one.

[brianhn1]

Originally Posted by scalbert

Personally, I would like to get a better understanding and get to the bottom of this. The logs I have captured have suggested CPS offsetting is not learned out. In addition, the programming in me as well as knowledge on Siemens programmable controllers would suggest the same as well.

I'm interested in hearing what you have to say as to how ignition timing control is done by the MSD80/81 based on what you have seen with Siemens PLCs.

PS. What happened to doing some runs at the dragstriiiip in Gainesville? (I'm nearby). Hope you're still around and better give me a headsup.

[Sparky66]

Originally Posted by TheTwinz

And you are right, there are tons of things the Procede can do that JB can't, and a lot of the things it can do might not necessarily apply to the N54.

Since many have been led to believe that the ECU in the N54 uses some sort of super hybrid technology and that it deviates away from basic engine 101 tuning ideals, is farcical.

Originally Posted by TheTwinz

We all have to remember that the Procede is a universal application meaning it works on a ton of different cars.

I'm sure I've heard Terry drum that into most people on his forums........good marketing ploy no doubt as his was built to run exclusively on the N54....... so it must be better

Originally Posted by TheTwinz

That is why it is more advanced and has more features, and safety measures for all varieties of cars. I'm still debating whether or not this whole timing debacle is really as bad as Shiv would like the public to think it is.

Trust me.......the N54 is like any other direct injection engine that's been tuned in the past and as to the piggyback systems intercepting signals and then modifying the RPM, TPS, Boost, IAT, O2 voltage and Road Speed
they are all basically doing the same thing..be it the Procede or JB3.

Where the Procede does things like most other piggyback tunes is with the required hardware to allow for Timing Offset triggers by adjustment of the Crank Position Sensor..........which up to this point in time has proven not to be learned out as some have suggested.

Where the Procede has the upper hand is with the implementation of Canbus and its datalogging capability to manipulate parameters to optimise the tuning potential.

[adrian@vishnu]

Originally Posted by TheTwinz

I agree with this post 100%! Adrian should be the spokesperson for Vishnus company. Adrian clearly states the fact and respects that he too isn't sure whether or not CPS adds anything. He doesn't belittle anyone, nor try to scare people into thinking that the JB3 is going to blow up your engine.

And you are right, there are tons of things the Procede can do that JB can't, and a lot of the things it can do might not necessarily apply to the N54. We all have to remember that the Procede is a universal application meaning it works on a ton of different cars. That is why it is more advanced and has more features, and safety measures for all varieties of cars. I'm still debating whether or not this whole timing debacle is really as bad as Shiv would like the public to think it is.

You may have read me a little wrong. I have my opinions on whether CPS does something, and they are well aligned with most of the data I have seen presented on this forum and what I have seen myself from my own logging. However I realise that the ECU reacts to so many variables that provide different results that many perceive as inconsistency, and it is therefore possible to obtain data that may "look" to provide evidence to the contrary. Therefore I am not going to enter this "discussion" which would become an endless circle of analysis of logs and rebuttals of out-lying datalog cases. But I can say that I am quite sure of my own opinion. I just put my opinion aside to present data that is not as debatable.

Also, although the Procede is based upon a generic solution, it is now customised to the N54 application. It happens to do some things that cannot be done with the JB system architecture, but we think these additional features are very valuable. Just because the competition cannot do these things and claims they are not necessary does not mean that the Procede has a bunch of features that do not add value to the N54 platform. The N54 is not as different to other engines as some would believe. The boost control mechanism is unusual, but most other things are pretty textbook stuff.

Originally Posted by brianhn1

Need some clarifications:



Are you referring to user defined torque requested?



You mean turbo shaft speed has to increase with engine RPM? Engine torque demand will directly correlate with turbo shaft rotational acceleration during the spool phase.

BMW chose to use small turbos because of their low moment of inertia. Turbo lag is not a huge issue in the N54 application.



VANOS is used to advance the intake and exhaust camshaft timings depending on the engine speed and torque demanded. It does not take a finite time, as distance to advance depends on starting and final cam timing.

How do you know that ignition timing is dependent on double VANOS positioning?



ECU will change certain parameters to control EGTs depending on condition states such as cold start, normal engine oil/water temperature levels, cruise with depressed catalyst converter temps. To increase, either lean the mixture or retard timing. However, the engine retarding timing reactively under high torque demand situations does not mean it is because of low EGTs.



Ignition timing is reactive towards input parameters and the engine operating state.


The ECU seems to have lots of inputs it relies upon to determine ignition timing.
If the ECU has so many inputs, then how it is able to refer to hundreds or possibly thousands or even tens of thousands of "tables"? ECU is clearly no supercomputer...but acts like one.

I think we are getting caught up with semantics here. I don't think it will help anyone here to get into a level of technical detail that goes beyond most readers understanding. So just a brief clarification of your points

BMW chose small turbos no doubt, but there is still lag. In low gears the turbos are playing catchup with the engine... to a lesser degree than some other setups, but the turbine shaft speed, wastegate position and exhaust back pressure will be different at 5000RPM say in 6th gear to in 1st. Generally in a lower gear at the same boost and RPM, the wastegate will be closed more, the exhaust back pressure will be higher.

By saying Vanos does not take a finite time to move are you saying it takes infinite time??

I have done alot of tuning before, and although I do not have the BMW code or algorithms, I have worked with alot of modern engines. Modern ECUs will take many sensor inputs and come up with a calculation of the mass of air per cylinder firing. This will then be used to set fuel and ignition targets. One of the parameters used to calculate the air mass per firing will be the VANOS position (effects Volumetric Efficiency which is at the core of speed density engine management systems)... so a different VANOS position gives different air mass, which results in different ignition timing. I cannot say anything for certain about this ECU without checking the code which I do not have, but it is highly likely.

ECU is no supercomputer. Many inputs are used to determine the air mass per firing, and then this is the primary load source for many of the maps. The ECU probably has 10s of maps (not hundreds), and many of the maps do the same things for different conditions, most maps are not in use all the time.

[Prince ///M]

Dear Adrian,
looking at the data Jp presented, in 3rd gear pull (so with mainly the same load and the same acceleration rate) the car has respectively almost 10deg of ignition advance if it is performed 'stand alone', and near to 0 (maybe 2 deg) if it is realized in sequence with first and second gear acceleration.

Your description about parameters that influence timing is correct, but IMHO none of the presented dependencies can explain such a big difference.

We are not talking about different timing in different gears... but different timing in THE SAME GEAR (and in the presented case IAT are not a possible expalination because also without IC the temperature increase is negligible in first and second gear pull).

Probably, the only parameter that can lead to some variation in timing is calculated EGT, that are maybe higher due to the longer test and higher mean rpm during pull... but such a difference is still a mistery to me (100% more respect to procede maximum used correction).

[Bubbles]

Originally Posted by scalbert

I am currently in Gainesville, FL...

Jealous, stay away from those 18 year old freshman....they're trouble