Okay, I don't have my laptop with me, so I'll look at the logs tonight and see if those PIDs are there


Sent from my iPhone using Tapatalk

What is the boost/load rpm ?

Not sure what you are asking.

Btw, retread your first post - I can tell you from memory that desired and actual throttle position are nearly identical.


Sent from my iPhone using Tapatalk

Curious of the load when its happening?...and desired tip is turbo inlet pressure

Gotcha - will look tonight.


Sent from my iPhone using Tapatalk

Desired tip is basically desired boost....so if that is flat and tip is rising then its attempting to maintain boost but it doesnt have to be that abrubt...the wastegates should operate smoothly.....that seems like a hole in the tune..wastegate duty should be smooth and sweeping and cruise and while steady on the gas pedal

Also want to log desired intake cam timing and actual intake cam timing and see if the cam is rolling...shouldnt be but if you are at an rom where its transitioning that that can affect load which would show as pulsing...the cam should roll smoothly

AJP turbo,

I see you have downpipes like I do, and I am presuming you don't have the same issues with the partial throttle mild surging.  If that is the case, can I ask you, are you running a custom sct tune and who did the tuning or a canned tune, since I would like to try the tune you are using and see if it makes a difference. Thanks.

I havent noticed this issue but id like to see the exact operating conditions and see if i can replicate

I am running my own tune now....in the past i had an unleashed tune and didnt notice it either

The closest tune you could get to me now would be to contact matt at gearhead automotive performance....my tune is becoming vastly different lately though

Quote from: xkrexplorer on April 20, 2016, 01:52:41 PM
AJP turbo,

I see you have downpipes like I do, and I am presuming you don't have the same issues with the partial throttle mild surging.  If that is the case, can I ask you, are you running a custom sct tune and who did the tuning or a canned tune, since I would like to try the tune you are using and see if it makes a difference. Thanks.

xkrexplorerer if you would be kind enough to setup a signature,thanks.  Z

Quote from: xkrexplorer on April 20, 2016, 01:52:41 PM
AJP turbo,

I see you have downpipes like I do, and I am presuming you don't have the same issues with the partial throttle mild surging.  If that is the case, can I ask you, are you running a custom sct tune and who did the tuning or a canned tune, since I would like to try the tune you are using and see if it makes a difference. Thanks.

I suspect the issue is very common, but not throughout. Perhaps strategy driven? Especially since everyone I have found complaining about it said that it was worse with a tune, presumably since the boost jumps are exacerbated.

I bet many probably have it and don't know it, since the conditions have to be so specific. If you drive entirely in the city, or have a heavy foot that forces a downshift at every hill, you my never notice it.

I agree with John Miller, its there.  If you drive the thing like you stole it, you won't notice.  If you are on a rough and non smooth rode or an older highway, you may think its just motion from the highway. For me, on the drive home from work, I have a very gradual incline on the highway.  Maybe rises 300 feet over three miles.  Cruising at 65 mph on this incline, my explorer will buck ever so slightly as long as gas pedal is depressed 1/4 or less.  Give it gas and accelerate or downshift and its gone. You can feel it in the wheel and slightly in seat.  Passengers may not notice it.  Radio off, and I can hear the bypass valve dumping if I concentrate.  So I vented my front bypass valve to air and went for a ride.  Sure enough, dumps boost, cycling every second or so as long as I am under those conditions. Worse when temp is colder for me.  Does not occur in open loop (wot or when engine warming to operating temp).  I can also replicate it pretty much on demand on shorter country rode hills if I give 1/4 or less pedal and don't let the car downshift.  I am guessing in the city, no issue really or if you have a heavy foot, you won't notice.

Agree 100% - except I never noticed it being worse in colder weather. The rough roads thing is the reason my dealer couldn't replicate -- all the highways around them are rough as hell.

I thought the steering wheel feel was my imagination - glad to see I'm not crazy

Sent from my iPhone using Tapatalk

TIP Boost is orange, Tip Boost desired is bold green.

Load is the thinner lined green. 

Check this out.  It is a small piece of a different run under similar conditions.  It shows boost (orange) and boost desired (green) in 6th gear, then a downshift to 5th (blue).  Look how much it smooths out with the downshift.



Again, this is a different run than the rest of the data logs I posted both before and after this post, so don't try to match it up against the other logs.  This run was specifically to log the 6th to 5th results.

AJP, I did find "Intake Cam Position Desired."  Not sure if this is what you were looking for.