[adrian@vishnu]

I just wanted to make note that there is not a direct corelation between DC and wastegate position except in steady state conditions (and even that can vary with the exhaust flow/pressure which pushes against the wastegate flap). DC can change much quicker than wastegate position, as the wastegate position control is a pneaumatic system with restrictions and mechancial momentum. It will have a much larger time constant than the electronics. Therefore it may take several hundred ms to reach a direct corelation. This is important to note as we are arguing about very short spikes of high and low DC. It is likely that just because the DC goes to 100%, does not mean the wastegate actually went fully closed or even near it. It is more likely that the brief spike simply worked to accelerate the wastegate to the desired position quicker without actually moving it any further than it would have moved with a less response control system. The breif spike simple fills the wastegate actuator to desired pressure quicker rather than actually changing the max/min pressure achieved.

Also one thing I have noticed with these cars is that there seems to be just as many people with unmodified cars having trouble with fuel pumps and wastegates as there are in modified cars. One has to ask the question whether the tune has any effect on these failures or the failures are simply poor quality manufactured parts that would have gone regardless of the way they are operated.

Adrian

[Bimmer335i07]

As stated previously, if you don't have anything to contribute or have any real questions, please stay off this thread.

[OpenFlash]

Next batch of partial throttle/boost response/accuracy testing is going to be even more interesting. However, in-dash boost display development and the need to change resistors in the jb3 as per Mike's suggestion took time away from the rest of the testing that i was planning to wrap this previous weekend. Still have to work out how to log jb3 wastegate dc without giving up other useful datalog channels. Should have it figured out and done this week. I wish there were more hours in the day.

Shiv

[Mike@N54Tuning.com]

Originally Posted by shiv@vishnu

I wish there were more hours in the day.

Shiv

You an me both As for the resistors just get a standard board. There is no need to be swapping resistors back and forth.

Mike

[supracg]

Originally Posted by adrian@vishnu

I just wanted to make note that there is not a direct corelation between DC and wastegate position except in steady state conditions (and even that can vary with the exhaust flow/pressure which pushes against the wastegate flap). DC can change much quicker than wastegate position, as the wastegate position control is a pneaumatic system with restrictions and mechancial momentum. It will have a much larger time constant than the electronics. Therefore it may take several hundred ms to reach a direct corelation. This is important to note as we are arguing about very short spikes of high and low DC. It is likely that just because the DC goes to 100%, does not mean the wastegate actually went fully closed or even near it. It is more likely that the brief spike simply worked to accelerate the wastegate to the desired position quicker without actually moving it any further than it would have moved with a less response control system. The breif spike simple fills the wastegate actuator to desired pressure quicker rather than actually changing the max/min pressure achieved.

Also one thing I have noticed with these cars is that there seems to be just as many people with unmodified cars having trouble with fuel pumps and wastegates as there are in modified cars. One has to ask the question whether the tune has any effect on these failures or the failures are simply poor quality manufactured parts that would have gone regardless of the way they are operated.

Adrian

Agreed, this wastegate talk is kind of OT, we are talking about boost control. If faulty engine parts are of concern then you cannot ignore the hpfp, and we all know both tunes increase boost and increase pressure on the hpfp. These parts are accepted as faulty with or without increased stress.
If a tuner disagrees with that statement (in regard to the wastegates) then I am curious to know what kind of compensations they have implemented for the notorious hpfp.

Also, (even though this isn't on topic) the reason I was a little confused by Mike's posts, is that DC does not directly correlate to the back and fourth movement of the wastegate (or snapping), this is vacuum and compressed air guys there is no instant "snap", air builds up and gradually (sometimes more gradual than others) moves the arm to the desired position and holds, briefly increasing DC to 100% may be used to increase the rate that air is used in order to move the arm faster. (Correct me if I am wrong)

[Jeff@TopGearSolutions]

Originally Posted by supracg

Agreed, this wastegate talk is kind of OT, we are talking about boost control. If faulty engine parts are of concern then you cannot ignore the hpfp, and we all know both tunes increase boost and increase pressure on the hpfp. These parts are accepted as faulty with or without increased stress.
If a tuner disagrees with that statement (in regard to the wastegates) then I am curious to know what kind of compensations they have implemented for the notorious hpfp.

Also, (even though this isn't on topic) the reason I was a little confused by Mike's posts, is that DC does not directly correlate to the back and fourth movement of the wastegate (or snapping), this is vacuum and compressed air guys there is no instant "snap", air builds up and gradually (sometimes more gradual than others) moves the arm to the desired position and holds, briefly increasing DC to 100% may be used to increase the rate that air is used in order to move the arm faster. (Correct me if I am wrong)

I think in lamens terms your trying to say..

If WG DC goes from 0-100 back to 0 in an extreme short period of time... its likely the ACTUAL WG movment might only be 0-30-0 (using arbitrary numbers).... We can deduce from that scenario that even though 100% is on the duty cycle the actual motion MIGHT be significantly less due to the delays in this equipment?

BTW this WG DC stuff is boring I must say LOL

[OpenFlash]

More Data..;

First up, Procede v4 boost performance step testing
This tests the tunes ability to accurately and quickly target boost with respect to throttle position. The absolute ideal result is when the boost logs follow the throttle logs perfectly. In reality, this is impossible with a turbo engine because there is always some inherent turbo lag. So boost will always be slightly behind throttle demands. This lag should be minimized as much as possible.

The ability of turbo system's boost pressure to follow throttle input accurately and quickly (minimal lag) is what defines its "fun to drive" characteristic. It also makes a car easier to drive because accurate and predictable power response allows the driver to driver closer to the cars limits (both straight line AND cornering) without over-stepping them and having to apply correction which hurts performance.

Video:

Datalog (entire):


Datalog (zoom):


Next up: Step and Step Down testing with Procede v4 (with wastegate DC logs)

After that: Tests repeated with JB3 2.0 running standard resistors and suggested throttle gain setting.

Cheers,
shiv

[jpsimon]

these results will be very interesting. can't wait!

[Mike@N54Tuning.com]

Originally Posted by adrian@vishnu

I just wanted to make note that there is not a direct corelation between DC and wastegate position except in steady state conditions (and even that can vary with the exhaust flow/pressure which pushes against the wastegate flap). DC can change much quicker than wastegate position, as the wastegate position control is a pneaumatic system with restrictions and mechancial momentum. It will have a much larger time constant than the electronics. Therefore it may take several hundred ms to reach a direct corelation. This is important to note as we are arguing about very short spikes of high and low DC. It is likely that just because the DC goes to 100%, does not mean the wastegate actually went fully closed or even near it. It is more likely that the brief spike simply worked to accelerate the wastegate to the desired position quicker without actually moving it any further than it would have moved with a less response control system. The breif spike simple fills the wastegate actuator to desired pressure quicker rather than actually changing the max/min pressure achieved.

Also one thing I have noticed with these cars is that there seems to be just as many people with unmodified cars having trouble with fuel pumps and wastegates as there are in modified cars. One has to ask the question whether the tune has any effect on these failures or the failures are simply poor quality manufactured parts that would have gone regardless of the way they are operated.

Adrian

Sorry for the late reply, missed your post. I agree DC=100% does not mean the wastegate instantly goes to 100% but rather starts moving aggressively in that direction. You may go DC=0% before it gets there to snap it back. The DC changes are the result of PID boost feedback so it follows that if DC is moving from 100% and back there was more aggressive wastegate movement involved creating the boost feedback.

Mike

[supracg]

Shiv those logs look really good with respect to throttle response. Also lets end this wastegate talk..we are talking about boost response not faulty engine part compensations with regard to tuning. And if one (tuner) thinks weak wastegate history with the n54 is a valid argument/excuse for weak(er) boost control, may I ask what compensations they have implemented for the hpfp?

I just want to make sure Mike is legitimately worried about the faulty engine parts of the n54 and not making excuses for the upcoming logs.

Could be wrong though, maybe the JB3 logs will be even better. We'll see

[adrian@vishnu]

Originally Posted by Mike@N54Tuning.com

Sorry for the late reply, missed your post. I agree DC=100% does not mean the wastegate instantly goes to 100% but rather starts moving aggressively in that direction. You may go DC=0% before it gets there to snap it back. The DC changes are the result of PID boost feedback so it follows that if DC is moving from 100% and back there was more aggressive wastegate movement involved creating the boost feedback.

Mike

Mike I am not going to disagree that we move the wastegate more "aggressively". We make no apologies for that, and it is what we set out to do in the first place. In fact any tune that runs more boost will be doing the same to a lesser degree. Does it make any difference to wastegate life reliability... I think not, but everyone is entitled to an opinion since fact is not available. Are we at Vishnu willing to compromise boost response based on a "what if?"... no we are not. And I would suggest BMS would also feel the same way if they had the same capability of direct driving the solenoids.

This would not be the first time that Vishnu has been accused of creating some unreliability issue in algorithms we use only to have it copied by the competition... lagfix was accused of "overspooling turbos". Bogfix had similar accusations. Both of which have been similarly used by the competition. This is just another round of the same thing.

Every now and then I have a look at the "other" forum and get amused by the claims of how everyone here is biased but everyone there is objective. If you want to be objective... tell it how it is. Rather than looking for little things you can use to bring down a good system, just say that it looks good, and seems to be something you may be looking at doing down the track. I think it would be better for both of us in the long run.

Can you atleast admit (wastegates aside) that the V4 boost response is impressive? It would save arguing over the validity of logged data when it arrives shortly.

Adrian

[Mike@N54Tuning.com]

Originally Posted by adrian@vishnu

Mike I am not going to disagree that we move the wastegate more "aggressively". We make no apologies for that, and it is what we set out to do in the first place. In fact any tune that runs more boost will be doing the same to a lesser degree. Does it make any difference to wastegate life reliability... I think not, but everyone is entitled to an opinion since fact is not available. Are we at Vishnu willing to compromise boost response based on a "what if?"... no we are not. And I would suggest BMS would also feel the same way if they had the same capability of direct driving the solenoids.

This would not be the first time that Vishnu has been accused of creating some unreliability issue in algorithms we use only to have it copied by the competition... lagfix was accused of "overspooling turbos". Bogfix had similar accusations. Both of which have been similarly used by the competition. This is just another round of the same thing.

Every now and then I have a look at the "other" forum and get amused by the claims of how everyone here is biased but everyone there is objective. If you want to be objective... tell it how it is. Rather than looking for little things you can use to bring down a good system, just say that it looks good, and seems to be something you may be looking at doing down the track. I think it would be better for both of us in the long run.

Can you atleast admit (wastegates aside) that the V4 boost response is impressive? It would save arguing over the validity of logged data when it arrives shortly.

Adrian

How the tunes affect the wastegates and how that differs from stock is worthy of discussion don't you think? Like I said before there is no accusation there and no reason to be defense about it. We may find the stock and V4 tune move the wastegates slower and more precisely than the JB3 does. It's simply a discussion item.

On V4 boost control aside from a dyno that looked strange it looks to work well and you guys have done a good job with it IMO. I know from my logs and beta testing the JB3 boost control also works extremely well. The performance of each depends greatly on the PID tuning and how well they are dialled in. The JB3 has the benefit of being a more "tried and true" approach on this platform so we're very familiar with the safeties in place and how it operates. The V4 is a new approach and thus less is known about it. It may turn out to be superior, worse, or the same in terms of accuracy and/or reliability when implemented among thousands of cars. Time will tell and vendor marketing threads like this one are simply here to pass the time until then.

Mike

[Mike@N54Tuning.com]

Originally Posted by supracg

Shiv those logs look really good with respect to throttle response. Also lets end this wastegate talk..we are talking about boost response not faulty engine part compensations with regard to tuning. And if one (tuner) thinks weak wastegate history with the n54 is a valid argument/excuse for weak(er) boost control, may I ask what compensations they have implemented for the hpfp?

I just want to make sure Mike is legitimately worried about the faulty engine parts of the n54 and not making excuses for the upcoming logs.

Could be wrong though, maybe the JB3 logs will be even better. We'll see

I've run through similar JB3 step tests and boost control is perfect. I'll take a video one of these days. Even Shiv posted a step test JB3 log on the first page and it was fine using his misconfigured modified board. If the JB3 settings are off you'll get some overshoot but can easily adjust them. I haven't tried the V4 but it may be possible to misadjust it as well if they give you access to PID parameters.

Fuel pressure is altered somewhat gingerly as a result of epidemic of fuel pump failures. I don't believe the tuning changes have led to shorter fuel pump life but I wouldn't expect them to lengthen life either. How tuning impacts wastegate rattle is something worthy of looking in to IMHO.

Mike

[jpsimon]

I couldn't even tell you what wastegate rattle is 40k strong, well... soon I'll be back at 0 though

[adrian@vishnu]

Originally Posted by Mike@N54Tuning.com

How the tunes affect the wastegates and how that differs from stock is worthy of discussion don't you think? Like I said before there is no accusation there and no reason to be defense about it. We may find the stock and V4 tune move the wastegates slower and more precisely than the JB3 does. It's simply a discussion item.

On V4 boost control aside from a dyno that looked strange it looks to work well and you guys have done a good job with it IMO. I know from my logs and beta testing the JB3 boost control also works extremely well. The performance of each depends greatly on the PID tuning and how well they are dialled in. The JB3 has the benefit of being a more "tried and true" approach on this platform so we're very familiar with the safeties in place and how it operates. The V4 is a new approach and thus less is known about it. It may turn out to be superior, worse, or the same in terms of accuracy and/or reliability when implemented among thousands of cars. Time will tell and vendor marketing threads like this one are simply here to pass the time until then.

Mike

It makes for interesting enough discussion I guess, but that is all it can be as there is no way to do any metrics on failures. I am quite certain that the Procede has the most control authority on the wastegate out of any tune currently available, and this will be shown in logs. As to whether it effects wastegate reliability... nobody can say at this stage. What can be measured though is how it effects boost response. I believe that wastegate authority will translate to superior boost response, but I will wait for the logs to see if this is the case.

Our new method is certainly not as proven. It is still in beta in perhaps a few hundred cars at the moment. However I am certain it is heading the right direction from a driver satisfaction perspective. Of course different people have different desires in throttle response, but I do not believe it can get any quicker than what we have it without mechanical changes. We put alot of effort into the PID optimisation, and I know we have alot more control of the PID than (almost) all other tunes since the DME has no part to play in our PID tuning. Some will argue that the DME can do a better job, but they should really stop making assumptions and test both including logging and see if they still think the DME can do a better job. Some will argue we lose safety, but seeing we actively monitor the DME target and DME DC at all times, we have not lost any safety. If the DME shuts down boost, the V4 will do the same. We have even implement methods to control DME throttle closures to allow it to operate most of the time for normal operations (traction control, excessive boost spikes etc.) but completely prevent throttle closure when we want to (small boost spikes).

Anyway, this part of the discussion we have had before. Personally I am not interested in debating how the wastegate durability will be affected. It is nothing more than a deabte that cannot be proven, and I more interested in performance aspects of discussion. That is not to say I do not care... just that I have formed my opinion, and it will not change without more hard data.

Do you know if I would be welcome to join N54tech? I know Shiv is not, so I have not tried. I would be happy to debate aspects of the tunes with Terry directly and would do so in a controlled and honest manner as long as my posts are not editted by others and I am not shutdown for having a difference of opinion assuming I am not providing false info or data (and then you can ban me, but be prepared to defend your position on what is false and why).

Adrian

[Belarus]

Originally Posted by adrian@vishnu

.....
Do you know if I would be welcome to join N54tech? I know Shiv is not, so I have not tried. I would be happy to debate aspects of the tunes with Terry directly and would do so in a controlled and honest manner as long as my posts are not editted by others and I am not shutdown for having a difference of opinion assuming I am not providing false info or data (and then you can ban me, but be prepared to defend your position on what is false and why).

Adrian

You most likely will be welcome on [Admin Notified] forum. Terry and other tuners are part of it.

[yandy]

Originally Posted by adrian@vishnu

Do you know if I would be welcome to join N54tech? I know Shiv is not, so I have not tried. I would be happy to debate aspects of the tunes with Terry directly and would do so in a controlled and honest manner as long as my posts are not editted by others and I am not shutdown for having a difference of opinion assuming I am not providing false info or data (and then you can ban me, but be prepared to defend your position on what is false and why).

Adrian

I for one I'm hoping you are. By far the most civil and useful conversations I've seen on here are between you and Mike. Having these discussions with the tuner himself would only help everyone. That's just my .02 cents though and I can't speak for everyone.

[huyner328]

I like Adrian much more than Shiv. I would venture to say that his presence on N54Tech would be welcomed. Can you guys, at some point, discuss the bogfix and how it's implemented between each tune? Maybe even shed some light on the components of what makes a bogfix work. TY!

[edo]

Originally Posted by huyner328

I like Adrian much more than Shiv.

ahhhhh....

[jpsimon]

Originally Posted by huyner328

I like Adrian much more than Shiv. I would venture to say that his presence on N54Tech would be welcomed. Can you guys, at some point, discuss the bogfix and how it's implemented between each tune? Maybe even shed some light on the components of what makes a bogfix work. TY!

There is no active "bog-fix" with V4, if you shift fast enough (.3-.35s) it just holds boost, basically no need for an additional feature to force it to do this.

[huyner328]

Maybe I'm a slow shifter but with my JB3, I still feel a slight bog and I shift fairly fast. I don't have an SSK however.

[OpenFlash]

Originally Posted by huyner328

I like Adrian much more than Shiv

Dammit... My mom says the same thing.