Wastegate dumping boost

Gray Brick · July 24, 2016, 12:36:42 AM

What would be the cause of the wastegate to go to zero?
The attached picture shows the boost is great and then it starts to drop off at around 80MPH

Any suggestions on where to start?

AnotherGreenFusion · July 24, 2016, 12:55:19 AM

can you post the actual log?

were you tracking dsd boost?

Gray Brick · July 24, 2016, 01:21:19 AM

Yes... see logfile.

SHOdded · July 24, 2016, 06:39:35 AM

Two things I noticed: a) the FRP is constantly oscillating (not by a whole lot (500 psi maybe) under WOT and b) lambse is identical between banks 1 & 2 at part throttle at 23mph starting at row 6444.

Gray Brick · July 24, 2016, 11:36:26 AM

Do you think the ECU opened the wastgate or should I be looking for a boost leak?

SHOdded · July 24, 2016, 11:47:46 AM

I think the ECu did if anything. Something possibly the issue with a sensor. Waiting for AJ to chime in.

FoMoCoSHO · July 24, 2016, 12:16:21 PM

GB, Look at throttle angle actual and dsd...

It looks like the ECU shut the throttle on you unless you inadvertently let off.

Any chance you forgot to turn off TC?

If not, we can't tell where the request came from because you're not logging torque source.

AJP turbo · July 24, 2016, 01:04:08 PM

That is one of the strangest logs I have seen.....There is an element of time involved....Like timers for the torque limits maybe...Ask torrie how the LAMBSE is coming down in a linear fashion as the pull goes on.....It's coming down independent of RPM , gear and load, I've never seen that and would have no idea how to do it.....Just guessing here but I'm thinking he is doing that in an attempt to correct the fueling for meth addition...Since I've not seen good logs with meth in terms of fueling

The car is over fueling because it doesn't know where the meth is coming from so stft's plummet and you reach the max amount allowed to be pulled

So you are commanding a leaner mix early in the pull and that may slightly help with trims which are about .85ish then as the pull goes on you command a richer mix so the car dumps more fuel plus your meth then the trims go to .75ish.

Something gets unhappy eventually and boost is dumped

It's really weird

You can get away with commanding .90 Lambda because in reality you will be richer than that because of the meth you are dumping and it will stay rich because you are dumping more meth than the ECU can compensate for to maintain lambda by removing fuel via STFT

Gray Brick · July 24, 2016, 04:50:01 PM

TC was definitely on.

What other PID's should I add to my logfile to help figure this out?

AJP turbo · July 24, 2016, 04:53:38 PM

Torque source like fomo said...fuel source, if available as a pid but ive never really looked at that much

FoMoCoSHO · July 24, 2016, 05:00:16 PM

Quote from: Gray Brick on July 24, 2016, 04:50:01 PM
TC was definitely on.

What other PID's should I add to my logfile to help figure this out?

You're at 40 so you are maxed out on pids.

If I were you I'd make another log file and get rid of the dupes you have for US units and just change the others to what you want.

Torrie can read both so set them to your preference.

Add torque source.

The more pids the lower the refresh rate.