86's behavior(tuning pov)

[yomny]

Just needed to vent before I drive my car into a building. I recall even when I was completely stock this car was sensitive to heat. I live in Miami so humidity and heat are you neighbors, you see them one minute then they're gone. I recall the car behaving like some oem turbo cars, happy when cold then not so much when hot, this surprised me coming from such low hp NA car.

Im now many moons from being stock and the behavior is still present. I feel very content with my tuner but this car has a damn personality. Please keep in mind most of my examples are a bit exaggerated to illustrate a picture or explain a behavior.
When it's hot my car usually struggles or lacks acceleration, I have to rev it up to get it moving, the acceleration isn't smooth at times. My morning drives to work which are still far from cool 80F, the car accelerate forward with easy, simply applying my foot to the gas pedal and still under positive pressure from the turbo(under o psi on boost gauge) the car is pushing me back in my seat moving along.

I'm sure most could say something's off with my tune based on my examples but I've had the chance to compare and is not tune related. I'm sure to a degree something could be tweaked but nothing a regular dyno tune or road tune would solve, unless hundreds of hours were to be spent tuning(still may not solve it ). I don't know if the motor is just sensitive if the stock ecu's logic is not so smooth. I don't really know how to explain or if what I say is making any sense.

If I go WOT from 2.5k it feels like I'm pulling trailer home to compared to going WOT after 3.5k or higher. I know the timing and everything is completely different and also under 3k I don't have any boost built. I would expect the feel at 5k to be the same, coming from 2.5k or 4k WOT. Similar weather conditions give me some time fine timing correction and then the next run would add timing, why does this damn thing fluctuate so much. The crappy part is that I feel all these little changes. I also understand gasoline varies from station to station, still.

Guess any experiences similar or completely different would be appreciated to see if anyone else feels the same way about their ride or if I just need to stop being so dramatic. Nothing really to solve, just hopped after spending so much cash the darn thing would be more appreciative. Yes i do know it's not a person and it can't thank me for changing the oil too often and trying to care for it as if it were my first born. Still just pissed.


Maybe this with the clutch acting up and not wanting to let 1st gear in is contributing to me hating this car, for now.

[s2d4]

Tune related.

[VitViper]

Pick up an ECUTek programming kit so you can datalog the vehicle. The investment in that cable on an F/I vehicle like yours is worth it, especially if you have to troubleshoot anything like this.

[yomny]

Originally Posted by VitViper

Pick up an ECUTek programming kit so you can datalog the vehicle. The investment in that cable on an F/I vehicle like yours is worth it, especially if you have to troubleshoot anything like this.

Oh yeah I'm a logging freak, i think I drive my tuner retarded with how annoying I could be just to trying to point out things in a tune I think are causing issues when I fact I don't really know squat.

Just now went for a drive, cool car, not after being driven for hours in traffic and still get fine timing correction up to 3 counts when loading the car.

At times when I try to power out of a tight turn I feel the car just bogs and am even though I hear and see the boost increasing, I ain't moving much.

[VitViper]

Well what is going on in the log during the situations where performance is poor vs when the behavior is excellent?

There's certainly a lot to look at, but start with overall timing (not just the corrections), AFR target & actual AFR (nice if you had a real wideband), VTC?

[yomny]

Originally Posted by VitViper

Well what is going on in the log during the situations where performance is poor vs when the behavior is excellent?

There's certainly a lot to look at, but start with overall timing (not just the corrections), AFR target & actual AFR (nice if you had a real wideband), VTC?

Appreciate your feedback. I do have a wideband. My AFR idle and cruise sits at an average of 14.2-14.6. Sometimes it goes up to 15 or it could drop to 13 but goes right back to 14's. I know my LTFT doesn't go beyond -+3.9 on a regular city drive(I checked this morning lol)

I'll try to take a log in the morning when things are usually nice and peppy as opposed to when I'm getting home after work which is when the car feels sluggish, after being driven in traffic for about 45mins.

Forgot to mention my WOT AFR usually goes from 11.8 to 11.3 as rpms increase to redline. Did a 5th gear pull to check recently and it was at 11.5, this is running 10.5psi.


The VTC part is where you got, me, is this cam timing? Side note, did a log from about 2.5k RPMs and the timing did stand out to me.. it start at 8.. climbs to about 15 or so by redline, going off my head so it could be +-2 degrees or so, I'll double check.


Is there a parameter that shows target AFR and actual, well I know the actual is the front 02 which isn't great but my Custom map O was calibrated to log the wideband AFR.

[VitViper]

Originally Posted by yomny

Appreciate your feedback. I do have a wideband. My AFR idle and cruise sits at an average of 14.2-14.6. Sometimes it goes up to 15 or it could drop to 13 but goes right back to 14's. I know my LTFT doesn't go beyond -+3.9 on a regular city drive(I checked this morning lol)

I'll try to take a log in the morning when things are usually nice and peppy as opposed to when I'm getting home after work which is when the car feels sluggish, after being driven in traffic for about 45mins.

Forgot to mention my WOT AFR usually goes from 11.8 to 11.3 as rpms increase to redline. Did a 5th gear pull to check recently and it was at 11.5, this is running 10.5psi.


The VTC part is where you got, me, is this cam timing? Side note, did a log from about 2.5k RPMs and the timing did stand out to me.. it start at 8.. climbs to about 15 or so by redline, going off my head so it could be +-2 degrees or so, I'll double check.


Is there a parameter that shows target AFR and actual, well I know the actual is the front 02 which isn't great but my Custom map O was calibrated to log the wideband AFR.

Closed loop isn't of concern -- the problem you have is under load. VTC is cam timing. You need to log the situations where the issue crops up, and if it's intermittent, compare to what it looks like when everything is OK.

Actual AFR (wideband), cam timing, ignition timing (actual), load, manifold pressure just to name a few to start with.

[yomny]

Originally Posted by VitViper

Closed loop isn't of concern -- the problem you have is under load. VTC is cam timing. You need to log the situations where the issue crops up, and if it's intermittent, compare to what it looks like when everything is OK.

Actual AFR (wideband), cam timing, ignition timing (actual), load, manifold pressure just to name a few to start with.

So city driving isn't' closed loop? I know it isn't so simple, but im feeling the hesitation, bogging during mild acceleration not really when im going WOT.. but then again this is all going over my head. Anyway you'd be able to see one of my logs? Driving up a little expressway ramp, slight incline, I give it gas at low rpm's and bog.. of course, this isn't all the time, normally given this same scenario the car just pulls forward as boost is building, very progressively.


Thanks a lot for your help, this may not solve anything until my tuner checks stuff out but definitely helps see things from a different perspective.


Does close loop switch to open when under X load? I thought it was usually going WOT.

[Kodename47]

Equivalence ratio commanded is the commanded AFR.

[VitViper]

When your AFR drops out of stoic targets, you're typically no longer in closed loop, it depends on how hte map is setup sometimes.

Your bogging is happening during mild acceleration events, which I'm assuming is happening either before boost builds, or during light amounts of boost -- hard to say without seeing the data as I'm just going off your description.

Yes I can view logs.

[yomny]

Originally Posted by VitViper

When your AFR drops out of stoic targets, you're typically no longer in closed loop, it depends on how hte map is setup sometimes.

Your bogging is happening during mild acceleration events, which I'm assuming is happening either before boost builds, or during light amounts of boost -- hard to say without seeing the data as I'm just going off your description.

Yes I can view logs.

You're absolutely right, the bogging happens just under boost and while building it(less than 5psi or so) Just yesterday I felt the weirdest thing, went wot and felt the hesitation(already at full boost) till about 5.5k or so, then a surge of power, sort of like vtec. That had never happened or at least not that I had noticed at least.

[VitViper]

Originally Posted by yomny

You're absolutely right, the bogging happens just under boost and while building it(less than 5psi or so) Just yesterday I felt the weirdest thing, went wot and felt the hesitation(already at full boost) till about 5.5k or so, then a surge of power, sort of like vtec. That had never happened or at least not that I had noticed at least.

Data of this behavior should help in troubleshooting and directing you towards a solution.

[Kodename47]

Hesitation like that would usually be either yoyoing timing (lots of correction happening) or AFRs going lean. I wonder whether the lower end could be due to load limits or similar.

[yomny]

Originally Posted by Kodename47

Hesitation like that would usually be either yoyoing timing (lots of correction happening) or AFRs going lean. I wonder whether the lower end could be due to load limits or similar.

I noticed the yoyo timing.. I have a log I did today and I get correction up to -3 and then addition, not back to back but fairly close in the event. I'll see if I could post some logs or something to show what im trying to explain as my tuning vocabulary is very limited. I didn't understand the part about load limits.


What puzzles me is that is not constant or always, just at times. That's why I initially thought it was a temperature thing.


Your help is very appreciated.