Tightmopedman9

Tuners Rejoice! Free Tuning For M4.4!

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No... The maximum boost a turbo can make is absolutely dependant of the actuator prelad.

A 100% duty cycle at a actuator preload of 9 psi will absolutely make more boost then a 100% duty cycle at a preload of 4psi.

I have tested this.

100% true!

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It's a simple matter really.

With a higher preload a higher pressure conducted through the TCV from the compressorhousing to the actuator is needed to open the wastegate.

So at a certain dutycycle the wastegate will be opened less with a higher preload, hence the pressure in the compressorhousing (boost) will rise until an equilibrium at a higher pressure is reached.

A 100% DC in tunerpro means that no pressure form the compressorhousing will reach the actuator.The wastegate will still be opend though at a certain moment because of the pressure in the turbinehousing.

The higher the preload of the actuator the higher this pressure will be and with that the higher the boost will be.

That's why my max boost at 100% DC was 1.4 bar with an actuator preload of 4.5 psi and 1.75 bar with a preload of higher then 7 psi already at 75% DC

Edited by Piet

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Guys, I've been discussing with Avinitlarge and for more than once we've seen here people saying that only when bits are 128 or over we have real knocking (even though we see real ignition retard per cylinder).

If that's actually true, what makes the ECU to retard ignition so many times when bits are way lower than 128?

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The 131 value means supposedly real knock was found and the following knock retard values is the active/adaptive (whatever) knock retard function of the ECU I believe (and not real knock).

I believe what happens often and it is not shown on your log image (at least I can't confirm on the first knock retard values) is knock retard without having any 128 or greater bit value or even any KR count. That would indicate no knock detection but yet knock retard which is what we are trying to understand.

knock.jpg

Like this for instance...

Edited by S70-R

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Yes, I was wondering about that too.

On what grounds exactely does the ECU decide to pull ingnition?

There often is knockretard while not only there's no greater then a 128 value but my Gizzmo knockdetector doesn't detect knock at all either.

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Yes, I was wondering about that too.

On what grounds exactely does the ECU decide to pull ingnition?

There often is knockretard while not only there's no greater then a 128 value but my Gizzmo knockdetector doesn't detect knock at all either.

That's great info!

Maybe the code guru guys (who have been away from this thread for a long time unfortunately) could investigate this further and get an answer.

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Mercuric seems to have vanished, Don't know what happened to him. Hopefully won the lottery and is sunning it up on a nice beach somewhere.

Knock has caused a dead end for me. I want to move forwards but can't, I know I do have a couple of points where I do get knock but 90% of what I am getting is not showing as knock (less than 128)

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I would try turning off adaptive knock by going under the knock tap setting motor temperature threshold for adaptive knock to the highest possible value.

I bet almost all of the knock you are seeing is adaptive, because it takes quite a long time for adaptive to stop influencing ignition retard after the ECU sees even a tiny bit of knock.

The engine will still detect knock if its detected, just no adaptive knock. IMO when tuning the ignition map its probably a good idea to turn off adaptive, tune your map to your liking then turn it back on, so if later down the road if your car has an issue and you arent logging for a couple of days / weeks the ECU can still keep the motor safe by having adaptive knock, instead of always having to dynamically detect the same knock, which might save your motor.

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This is another strange one, look at the line Ive highlighted
knock22614-2.jpg


I would try turning off adaptive knock by going under the knock tap setting motor temperature threshold for adaptive knock to the highest possible value.

I bet almost all of the knock you are seeing is adaptive, because it takes quite a long time for adaptive to stop influencing ignition retard after the ECU sees even a tiny bit of knock.

The engine will still detect knock if its detected, just no adaptive knock. IMO when tuning the ignition map its probably a good idea to turn off adaptive, tune your map to your liking then turn it back on, so if later down the road if your car has an issue and you arent logging for a couple of days / weeks the ECU can still keep the motor safe by having adaptive knock, instead of always having to dynamically detect the same knock, which might save your motor.

So set "Motor temperature threshold for adaptive knock control" to 175 and things will look a lot better

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After seeing Avinitlarges picture of the inners of his barometric pressure sensor I decided to open mine.

I have no errors from that sensor yet, but I prefer to work preventive. Besides that I do have a very rare fuel trim jump. I noticed it with lambda regulation off.

After that it occured very rarely. Difficult to trace the source of this phenomena. Excluded all possible sources including injectors. So I gave this a try.

2014062301.jpg

Similar solder rot.

The case has been opened partly by a Dremel and partly by this:

2014062302.jpg

After removing the old solder, it was clear that the pins need to be cleansed before resoldering.

Glued the sensor together with 2 component PU glue and some black pigment for the color.

I am convinced this sensor would have given complications very soon.

Not necessarily errors but definitely boost jumps and more fuel trim jumps.

Edited by razorx

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I agree. Thank you for your investigation about this sensor. Saved me money and time.

Besides you showed what's inside. So you made it easier to open it to others.

Edited by razorx

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So set "Motor temperature threshold for adaptive knock control" to 175 and things will look a lot better

Correct. You might notice a lot of your knock goes away.

From what I understand if the ECU sees knock it adds adaptive knock so whenever its around that part of the map it automatically pulls timing even if there isnt any knock. Can get really annoying when trying to tune the ignition map.

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@Simply Volvo:

Correct, the ECU keeps the adaptive knock values for a long time. A am not sure how long yet.It is effective as a protection mechanism, but far to aggressive.

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