[rob_evo_pnw]

Hello,

I will try to describe as best I can, it happens randomly, and I cant never mimic it when I try. I just happened to be logging when this happened at this time.

It happened twice yesterday, one time right before I was going to log as well..

Anyways, I come to a full stop, and then I would press on the gas slightly to go, the car would go like a few feet, and then it would feel like the throttle just closed or was cut and nothing would happen (foot still pressing on the pedal same amount), only momentum is moving the car, and then a rubber band affect would kick in and the car would lurch forward and go (as long as I didnt let off the gas) about a second later.

No cel, no random lights on my dash nothing. Only happens when I come to a stop and then when I press on the gas to go, not flooring it, just regular go. Car drives fine before and after, does not do this when actually driving around, cruising, or WOT

I set a mark on the log shortly after this occurred, tuner said he didnt see anything odd, but the occurrence did happen. I highlighted where I think is where I Was at a stop sign up to the point where I hit mark, Should start around line 115, end at 615

Unsure what parameters to even look at to begin with :-/

+2+2 for capacity, stock trans, FBO E85 2014, if that matters

TIA

Edit updated with a recent one that happened earlier in the evening, I believe it happened around line 2350, I hit mark a little after it occurred.
I was at a stop light completely stopped.
It went green and I pressed on the gas
About 1/4 of the way into the intersection, it felt like the car either stalled or throttle just got cut, my foot stayed pressed on the gas, and then shortly after it went back to normal and the car just took off like the rubber band effect I had mentioned

 

[alexdavis]

Hello,

I will try to describe as best I can, it happens randomly, and I cant never mimic it when I try. I just happened to be logging when this happened at this time.

It happened twice yesterday, one time right before I was going to log as well..

Anyways, I come to a full stop, and then I would press on the gas slightly to go, the car would go like a few feet, and then it would feel like the throttle just closed or was cut and nothing would happen (foot still pressing on the pedal same amount), only momentum is moving the car, and then a rubber band affect would kick in and the car would lurch forward and go (as long as I didnt let off the gas) about a second later.

No cel, no random lights on my dash nothing. Only happens when I come to a stop and then when I press on the gas to go, not flooring it, just regular go. Car drives fine before and after, does not do this when actually driving around, cruising, or WOT

I set a mark on the log shortly after this occurred, tuner said he didnt see anything odd, but the occurrence did happen. I highlighted where I think is where I Was at a stop sign up to the point where I hit mark, Should start around line 115, end at 615

Unsure what parameters to even look at to begin with :-/

+2+2 for capacity, stock trans, FBO E85 2014, if that matters

TIA

I have limited knowledge about this...but will ask you to try doing this in manual where you ARE SURE you are first starting in 1st gear. Does it still happen?
What I'm getting at is even in manual, but moreover in auto, there is a known phenomenon (better or worse probably according to a torque look-up table) where the car is "thinking" about what gear it needs to be in...gets it...and the rubber band effect or "hip hopping" occurs.

Just an idea to try.

Alexd

 

[rob_evo_pnw]

I have limited knowledge about this...but will ask you to try doing this in manual where you ARE SURE you are first starting in 1st gear. Does it still happen?
What I'm getting at is even in manual, but moreover in auto, there is a known phenomenon (better or worse probably according to a torque look-up table) where the car is "thinking" about what gear it needs to be in...gets it...and the rubber band effect or "hip hopping" occurs.

Just an idea to try.

Alexd

1000% I am in first, and in the log it says first
I am in auto as well.

Yeah it feels like, it is thinking, but stays in first at the time of the day prior to the rubber band effect lol

 

[rob_evo_pnw]

Can that be 'worked around'? It never happened before the TCM tune.

 

[rob_evo_pnw]

Posted another log of it happening about an hour ago

 

[L.L.]

I've avoided Auto mode for this very reason with the current GTR on EcuTek because of my experience with the Cobb TCM maps on the previous car. The transmission does very strange things and was even worse with the Cobb TCM programs than with the stock map. It felt like the TCM could never make up its mind and would upshift-downshift-upshift just by giving it some throttle. It's just less frustrating to use the paddles.

 

[rob_evo_pnw]

I've avoided Auto mode for this very reason with the current GTR on EcuTek because of my experience with the Cobb TCM maps on the previous car. The transmission does very strange things and was even worse with the Cobb TCM programs than with the stock map. It felt like the TCM could never make up its mind and would upshift-downshift-upshift just by giving it some throttle. It's just less frustrating to use the paddles.

So this is kind of normal then?

I do like that I can 'run yellow lights' with the TCM tune, before it would take a decade to downshift in auto

I was in R mode when this happened, but it happens in normal mode too

 

[L.L.]

So this is kind of normal then?

I do like that I can 'run yellow lights' with the TCM tune, before it would take a decade to downshift in auto

I was in R mode when this happened, but it happens in normal mode too

Based on the feedback posted from others and including my own experience, I would say unfortunately yes the quirks are pretty common regardless of mode of the switches.

 

[alexdavis]

Based on the feedback posted from others and including my own experience, I would say unfortunately yes the quirks are pretty common regardless of mode of the switches.

Based on the feedback posted from others and including my own experience, I would say unfortunately yes the quirks are pretty common regardless of mode of the switches.

...And it is worse when the engine/trans are cold.

Alexd

 

[rob_evo_pnw]

Yeah this didnt happen when the car was stock or prior to TCM, after the tcm tune, the day after essentially it did it at a stop sign again

More concerned is if I pull out to take a left with oncoming cars and the thing gives me the 1 second delay before it kicks in, because it is random

 

[L.L.]

Valid point. It took just one test drive with the TCM tune map loaded to realize it could become a safety issue at some point.

 

[bigc]

...And it is worse when the engine/trans are cold.

Alexd

+1, I notice this sometimes when the car is still warming up. To avoid this, I try creeping through stops so the trans stays in second instead of 'thinking about' shifting down to first. Everything is fine once the car is up to temp.

 

[rob_evo_pnw]

Car is definitely warmed up, 160+ easily, I think in the log it shows Trans temp

Tuner got back, he said to reset clutch learn, and set capacity to zero and touchpoints to zero, and mess with the Touchpoint B to where the car barely moves forward, he thinks the clutch is dragging.

 

[rob_evo_pnw]

Little update, tuner had me do negative -4 on the Touchpoint B, it hasnt happened since, but it is random..

 

[rob_evo_pnw]

It still happens unfortunately even at -4