Mad_SB

iTrader: (8)

Sup Folks,

So, I've held off on posting this for a while now as i don't feel like i have enough useful information to offer but....... My Sportback has just over 1,200 miles on it so far. Current modifications are test pipe, 3 port, mild road tune (just boost tweaks for direct boost control mode) based on GST base map for 93, X fmic, UR upper and lower IC Pipes.

In sport manual mode just after a wot shift I feel a little hesitation before the car picks up again. It almost feels like what you would expect if it were pulling a couple degrees of timing then giving it back.. or closing the throttle plate a bit then opening it back up.. Hesitation occurs a little bit after the shift is complete.

Sorry to sound so sketchy on the details but I have yet to be able to capture anything in the logs.... no knock sum, no funky boost correction (it was doing this before I ever went to direct boost mode or the 3 port), no funky throttle plate angle changes... nothing that I can find at all... rev's don't jump (so it's not clutch slip). It just feels like a couple dead spots post shift.... I

I'm going to try and nail it down a little more (like what rpm it happens etc) but I wanted to see if anyone else has experienced something similar... especially if they figured out what it was and got it sorted out.

omegis

iTrader: (2)

Try checking your hoses yet for any leaks or disconnects?

Easy to expect it to be ECU, but I'd play with the throttle while watching the engine bay for any noticable issues. May not turn up anything but at least that's one less suspicion.

sstevojr

iTrader: (7)

I experience the same issue when WOT.
I believe Bryan mentioned it before, something about when you turn the boost up, it affects the shift timing. The lower boundary table is the shift timing, so perhaps you are ending up in a different load than originally tuned for. But yes I get the same issue, especially if I shift before 5k (i.e. I dont let it go full WOT, cutting it off for whatever reason).

Mad_SB

iTrader: (8)

I have a seeking suspicion it is the crappy factory bov leaking under boost.... if it were a boost leak it would have blown off a coupler by now since I replaced everything at the same time when I did the X ic swap.

Mad_SB

iTrader: (8)

Interesting, I have played around with the lower bound table in the wot area's to make it a uniform 3 or 4 degrees lower than the high octane timing maps, it felt like keeping the lower bound table the same as the high octane map made the shifts a little too slippy for my taste (as in it was working the clutched a little too hard).

I might try keeping the lower bound the same as the high octane in the load areas (120 load and up or so) and see how that does.

sstevojr

iTrader: (7)

Lower Boundary s/b similar to Low Octane, not High Octane. otherwise it defeats the purpose, IIRC

Mad_SB

iTrader: (8)

Agree with that, what I am running is very close (within 1 or 2 degrees) to the gst 2.5 base maps.

sstevojr

iTrader: (7)

Sounds like you said you were changing Lower Boundary to match High Octane, or something very similar. This would result in the Low Octane being "null" for lack of a better word. I don't believe it has any part in this issue, but it could cause a different issue sometime later, such as when there is knock, and the computer tries to switch timing maps, only to learn it cant use those values because they are "capped" by the Lower Boundary.
Thats what I was trying to get at, just wasn't very clear about it

Mad_SB

iTrader: (8)

Sorry for the confusion on my part. Just to clarify the lower bound table I currently use is very similar to the gst 2.5 table, which is more advanced in the high load area than the stock lower bound table.

You were perfectly clear , I've tuned plenty of evo's in my day (mostly VIII's and IX's) and never once neglected the low octane timing table. I did my research before getting back into a 4B11 car (after a long break) and read up on the lower bound table before I ever picked up the sportback so no worries there

sstevojr

iTrader: (7)

Np!

RazorLab

iTrader: (8)

Logging wideband?

Mad_SB

iTrader: (8)

yup, i was messing with the standalone logger yesterday, had a bad formula so it didn't log the pull that was wonky. Afr hovers in the low 11's under boost, drops to 10.0:1 during shift then comes back to the low 11's by the time the hesitation happens... you can see it on the dips on the maf plot...... will try to get some logs today and pot them up. It doesn't feel like a missfire... it's smoother than that.. almost feels like when you have the boost error correction a little too sensitive and it starts hunting for the desired boost in an overshoot undershoot correction loop... strange.

Do you have / use dataloglabs? I'll post my stand alone logger deff with the logs if so.

RazorLab

iTrader: (8)

It shouldn't get so rich on shifts since the load shouldn't be changing at all with SST.

Yes send me the logs

Mad_SB

iTrader: (8)

OK,

So i got some good logs today. I'm almost positive that 95% of what i have been experiencing is waste gate duty cycle error correction. I got some good logs today with a big swing in ambient temps (around 50 this am and 75 this afternoon.

log0002 is from this AM with cooler temps. log0005 if from this afternoon with warmer temps. the 002 log i felt the hesitation... the 005 log i did not feel it. I think with warmer temps I'm closer to the correct base duty cycle (using direct boost). I must still be in the efficiency range of the turbo because a mild change in boost pressure equates to a big change in seat of the pants feel and g/s flow rate.

The txt file is a data log labs universal datalog format the matches my standalone logger logs. Rom is basically Bryan's 2.5 93 base with a few changes for psi boost.

RazorLab

iTrader: (8)

No logs...