My Dyno Chart

[Kasé Zomé]

3 quick pulls, hardly a break in between pulls. CA 91 pump. Not sure why the car kept making power with each successive run though... Thoughts on that?

[VCMpower]

Kept making more power due to adaptations. If you could have watched live data i am sure you would have seen fuel pressure on the rise after each run.

[Kasé Zomé]

^ got it. thanks for the insight. i wonder if it would gone up a bit if the dyno operator was aware of how our ECUs operate?

[VCMpower]

Originally Posted by Kas Zom

^ got it. thanks for the insight. i wonder if it would gone up a bit if the dyno operator was aware of how our ECUs operate?

Very welcome.

[IMG]

Originally Posted by VCMpower

Kept making more power due to adaptations. If you could have watched live data i am sure you would have seen fuel pressure on the rise after each run.

This seems very unlikely. The increase in power is more likely due to oil, coolant, and drive train getting up to more efficient operating temperatures. We've logged this on the dyno by doing multiple runs, let the car sit, and then do multiple runs again. If it were adaptations, then after letting it sit at rest, the car would dyno right where it left off...but that's not happening. Instead, if you let it sit long enough, the cycle starts all over again. Again if it were adaptations, this wouldn't happen.

Adaptations and fuel pressure don't seem to be related; not sure how they could be either because of the way injectors work. The ECU controls fuel pressure. It has two settings: 3-bar, and 5-bar. You can data log this with a BT tool if you want to learn more about it.

[Chriskm3]

Originally Posted by img

This seems very unlikely. The increase in power is more likely due to oil, coolant, and drive train getting up to more efficient operating temperatures. We've logged this on the dyno by doing multiple runs, let the car sit, and then do multiple runs again. If it were adaptations, then after letting it sit at rest, the car would dyno right where it left off...but that's not happening. Instead, if you let it sit long enough, the cycle starts all over again. Again if it were adaptations, this wouldn't happen.

Adaptations and fuel pressure don't seem to be related; not sure how they could be either because of the way injectors work. The ECU controls fuel pressure. It has two settings: 3-bar, and 5-bar. You can data log this with a BT tool if you want to learn more about it.

I wound not mind picking up few extra pointers here and there. Knowledge is power !!

[IMG]

Originally Posted by Chriskm3

I wound not mind picking up few extra pointers here and there. Knowledge is power !!

[VCMpower]

Originally Posted by img

This seems very unlikely. The increase in power is more likely due to oil, coolant, and drive train getting up to more efficient operating temperatures. We've logged this on the dyno by doing multiple runs, let the car sit, and then do multiple runs again. If it were adaptations, then after letting it sit at rest, the car would dyno right where it left off...but that's not happening. Instead, if you let it sit long enough, the cycle starts all over again. Again if it were adaptations, this wouldn't happen.

Adaptations and fuel pressure don't seem to be related; not sure how they could be either because of the way injectors work. The ECU controls fuel pressure. It has two settings: 3-bar, and 5-bar. You can data log this with a BT tool if you want to learn more about it.

I have data logged it. Unless my eyes deceived me and my data logger is crap I see what I see. If you drive your car around town barely hitting full throttle and minimal load that's what it adapts to. Dyno makes the motor work harder than most will ever do on the street. So you show me some credible evidence that the ECU does not increase fuel( obviously there are many adaptations , timing , cam timing ect.)as it adapts and I will concede. Until then it is just your opinion.

[M3takesNYC]

There is a difference between adaptions and adjusting timing on the fly. If you were driving with no WOT runs in awhile and you stick it on the dyno, it makes total sense that each WOT run may push the timing further as when in WOT mode it will try for the targets. You may not hit them at first because its too agressive but will settle out and find a timing that you can achieve which is higher than when you started. That is not an adaptation but rather the knock system sensitivity is always working to make changes second by second.

Adapations like long-term fuel trims would not be effected on WOT runs as those are established and do not change from slow driving to WOT. A/F doesn't really have adapations unless there is a problem of some sort.

If you simply do pulls and log timing you probably will see you closer to hitting max timing with each pull which explains this. Eventually you either hit the max target or you max out timing given your octane even if not able to hit max target of 32 degrees and then you would stop making power and eventually if heat was an issue start to lose power again because timing would be pulled.

[VCMpower]

Understood. I am talking a bit in generalities here as the OP had a simple question that did not require him pursuing a master tech position. Good explanation though. I was on the Dyno last week after a re-tune and watched fuel pressure go, in order, from 82psi 1st run, 88psi 2nd, 105psi 3rd. I was just trying to shed some light for the OP.

Originally Posted by M3takesNYC

There is a difference between adaptions and adjusting timing on the fly. If you were driving with no WOT runs in awhile and you stick it on the dyno, it makes total sense that each WOT run may push the timing further as when in WOT mode it will try for the targets. You may not hit them at first because its too agressive but will settle out and find a timing that you can achieve which is higher than when you started. That is not an adaptation but rather the knock system sensitivity is always working to make changes second by second.

Adapations like long-term fuel trims would not be effected on WOT runs as those are established and do not change from slow driving to WOT. A/F doesn't really have adapations unless there is a problem of some sort.

If you simply do pulls and log timing you probably will see you closer to hitting max timing with each pull which explains this. Eventually you either hit the max target or you max out timing given your octane even if not able to hit max target of 32 degrees and then you would stop making power and eventually if heat was an issue start to lose power again because timing would be pulled.

[IMG]

Originally Posted by VCMpower

I have data logged it. Unless my eyes deceived me and my data logger is crap I see what I see. If you drive your car around town barely hitting full throttle and minimal load that's what it adapts to. Dyno makes the motor work harder than most will ever do on the street. So you show me some credible evidence that the ECU does not increase fuel( obviously there are many adaptations , timing , cam timing ect.)as it adapts and I will concede. Until then it is just your opinion.

I think we're all here to learn from each other as best we can. I can tell you that some people have tested this on the dyno and the results were exactly what I gave you. That should be proof enough. I can also tell you that there are a few dozen entries in the Dyno Database that have full data logs and if you can't find them I can probably help you if/when I get time. Just take a look first on your own, and then let me know if you need me to point out some specific entries.

I'm also going to suggest if you can hook your car up the BMW diag tools (not BT tool) to see what adaptations are stored and not stored. I know there's a list of 10 adaptations that are stored, but I don't remember all of them off the top of my head. Heck, I don't remember hardly any of them off the top of my head. But I don't think there's anything in there for cam timing adaptations (that wouldn't even make sense). I think you'll find things mostly like AFR trims that are intended to compensate for the
degradations in the o2 sensors and CAT converters.

I only know of one guy who data logged fuel pressure, and all I can say is that I don't think it has anything to do with adaptations and the data showed a 3-bar setting and 5-bar settings. I don't think that data was ever published, but I know it exists. So I can't point you to a public place to show you this data. But I can ask the guy who logged it if he might consider posting it.

But I'm very interested to see what data logs you have. So please post them so we can all learn and I'll see if I can do whatever I can to help you learn from our data as well.

[pbonsalb]

The AFR all look very close at peak power. Does this ECU really use fuel pressure rather than injector pulse in order to hit the programmed AFR target? The variations are within 2%, and you can get that just about anytime you do several runs on a dyno. I am not sure whether I would draw any conclusions from the results, and that it may be just coincidental that power increased each run. You would have to log to see what actually changed.

[bradleyland]

Fuel pressure is once removed from the actual performance determinant. An increase in fuel pressure would only provide resolution to a condition where the AFR were too lean.

In other words, the relevant metric that determines output performance is AFR, rather than fuel pressure. If your AFR consistently shows too lean, you start looking for fuel pressure issues, rather than the other way around.

... unless you did a diesel conversion on your M3, then you always want MOAR FUEL!

[kavvmxuh]

There is a difference between adaptions and adjusting timing on the fly.

[Dave07997S]

Originally Posted by img

This seems very unlikely. The increase in power is more likely due to oil, coolant, and drive train getting up to more efficient operating temperatures. We've logged this on the dyno by doing multiple runs, let the car sit, and then do multiple runs again. If it were adaptations, then after letting it sit at rest, the car would dyno right where it left off...but that's not happening. Instead, if you let it sit long enough, the cycle starts all over again. Again if it were adaptations, this wouldn't happen.

Adaptations and fuel pressure don't seem to be related; not sure how they could be either because of the way injectors work. The ECU controls fuel pressure. It has two settings: 3-bar, and 5-bar. You can data log this with a BT tool if you want to learn more about it.

This..