[BADS335]

Ok, so I have a ProCede and log as much as I can. I noticed a drop in power quite often in the 4k-5k range. When looking at logs throttle shows 100% but CAN DME throttle dips down into the 70s and 80s and sometimes even way lower. Traction control and stability control are off. No KR. What else causes the TB to close?

[VNeBLOB42]

Over boost?

[BADS335]

Not looking like overboost.

I need help understanding everything that would close the TB. No KR detected. No other issues detected. Its frustrating cause you feel the drop in power when it does this pretty dramatically.

[Jeff@TopGearSolutions]

Post a log?

[wingman88]

same problem here! perhaps the diverter valves are weak....?

[BADS335]

I don't know what would cause the TB to close to know what to log. I have a log showing the TB closing at WOT. What should I show in the charts? Obviously throttle and DBW throttle, RPM, DBW boost actual. What else would be relevant? I have all the typical criticals. But no WG data.

[BADS335]

See attached. This is a 3rd gear pull. There is a dip later in the pull that goes down to 73%. This isn't nearly as bad as some situations. But you can see it dropped below 80% then slowly came back then dipped again.

[MrRager]

shouldnt the throttle body always be wide open? or is that only on the N52 and N55?

[BADS335]

Originally Posted by MrRager

shouldnt the throttle body always be wide open? or is that only on the N52 and N55?

This is exactly what I am trying to figure out. And what would cause it to close.

[BADS335]

Logged yesterday and this time the throttle opening time was really slow after a shift into 3rd.

[JamesM3M5]

Originally Posted by MrRager

shouldnt the throttle body always be wide open? or is that only on the N52 and N55?

No, the N54 has a traditional throttle, not like Valvetronic or stratified charge running.

Throttle closures come from boost exceeding target, especially after quick shifts without a full throttle lift.. Any boost leaks or wastegate troubles?

[cstavaru]

Originally Posted by BADS335

This is exactly what I am trying to figure out. And what would cause it to close.

I can't see your boost target in the log picture. Put boost and boost target on the same graph (if possible). Throttle closure at WOT is almost always caused by actual boost exceeding the boost target.

Moreover, the throttle maximum opening is about 81.08, so it does not "dip" into the 80s or 70s, 70 is a minor throttle closure. It may be that the graph is misleading you.

[BADS335]

Originally Posted by cstavaru

I can't see your boost target in the log picture. Put boost and boost target on the same graph (if possible). Throttle closure at WOT is almost always caused by actual boost exceeding the boost target.

Moreover, the throttle maximum opening is about 81.08, so it does not "dip" into the 80s or 70s, 70 is a minor throttle closure. It may be that the graph is misleading you.

Yeah I logged the wrong boost target. I logged DME target which only shows factory setting. I will try logging this and see if the events line up.

Actually on the throttle it will read up tp 99% so when it goes below it is definately closing.

Thanks

[cstavaru]

Originally Posted by BADS335

Actually on the throttle it will read up tp 99% so when it goes below it is definately closing.

The 99% one is the pedal reading, not the throttle. That is, if Procede is not different in logging than any other tool like BT, Cobb or JB4.

[BADS335]

I do not know what the node is that is being measured, but they call it "throttle" and it appears to follow the pedal. And DBW throttle appears to be the throttle blade possition.

[Coupes33]

I currently have the same problem with my 335i. What was the cause of the throttle closures and how was it rectified? I have carried out data logging with the Cobb and found that when the Boost Means Abs value exceeds the Req Boost value the throttle begins to close and the car begins surging. It happened out of the blue. My tuner has had the car on the dyno for a couple of hours and cannot find anything. All readings are normal apart from the above readings and no fault codes are coming up. What has all of a sudden caused the over boosting is the issue. He believes it will be something stupid. It will send me nutty trying to find the cause.

[mike@x-ph.com]

Originally Posted by Coupes33

I currently have the same problem with my 335i. What was the cause of the throttle closures and how was it rectified? I have carried out data logging with the Cobb and found that when the Boost Means Abs value exceeds the Req Boost value the throttle begins to close and the car begins surging. It happened out of the blue. My tuner has had the car on the dyno for a couple of hours and cannot find anything. All readings are normal apart from the above readings and no fault codes are coming up. What has all of a sudden caused the over boosting is the issue. He believes it will be something stupid. It will send me nutty trying to find the cause.

Throttle closure happens either when overboosting or i you have traction control activated ( you need to press the DSC button for 10 seconds until you get the yellow triangle to fully deactivate traction control).
Post a long and i will take a look at it and try to help out

[Coupes33]

Originally Posted by mike@x-ph.com

Throttle closure happens either when overboosting or i you have traction control activated ( you need to press the DSC button for 10 seconds until you get the yellow triangle to fully deactivate traction control).
Post a long and i will take a look at it and try to help out

Can you explain how deactivating the traction control stops throttle closures. I normally always have the traction control activated which is the normal state I thought for all BMWs. I have attached a Dyno Graph which shows in black (297.7kW/400HP) the original Dyno results after the custom Cobb tune in 2014, the blue line (277kW) which is the same tune showing the throttle closures and the red line (261.4kW) which is the generic Stage 2+ Cobb tune showing the same throttle closures. This was done to prove it is not software related. The boost graphs for each are also shown. The Datalog is from the Cobb Accessport using the custom tune.

[Digitalism]

You need to upload the data into datazap.me

It will be much easier for us to help.

[Digitalism]

I believe when traction control is enabled and the car senses any loss of traction it cuts the power to the car to regain traction and this is done by throttle closure.

[mike@x-ph.com]

Originally Posted by Digitalism

I believe when traction control is enabled and the car senses any loss of traction it cuts the power to the car to regain traction and this is done by throttle closure.

Exactly.

[Coupes33]

Deactivated the DTC but it made no difference to the surging while accelerating.