laggy/hesitant throttle response when upshifting?

[IronSean]

Originally Posted by Smoke Destructer

What exactly is that pedal trick supposed to do though? Is it like the other "pedal dance" that puts the car into some sort of diagnostic mode?

I'm assuming by Pedal trick you meant to make the throttle more responsive and not the clutch adjustment, here's my best guess:

The throttle is supposed to naturally become more responsive as the ECU learns the full range of motion of the throttle pedal, but by default includes a dead zone to be safe after an ECU reset. The pedal trick fast tracks that by leaving the car on but not running(and therefore safer to repeatedly push the throttle) but giving it plenty of examples of the range of motion to adjust the actuation point/dead zone to the full range.

Again, this is purely a guess.

[Porsche]

Originally Posted by Smoke Destructer

What exactly is that pedal trick supposed to do though? Is it like the other "pedal dance" that puts the car into some sort of diagnostic mode?

Originally Posted by Smoke Destructer

Very informative post Porsche, but I was actually asking about this when I said "pedal trick."

Anyone know what that is all about?

I do not understand that post you referenced. Does it, too, put "the car into some sort of diagnostic mode" as you wrote?

And whether it does or not, do you recall what problem they were addressing there?

[Porsche]

Originally Posted by IronSean

I'm assuming by Pedal trick you meant to make the throttle more responsive and not the clutch adjustment, here's my best guess:

The throttle is supposed to naturally become more responsive as the ECU learns the full range of motion of the throttle pedal, but by default includes a dead zone to be safe after an ECU reset. The pedal trick fast tracks that by leaving the car on but not running(and therefore safer to repeatedly push the throttle) but giving it plenty of examples of the range of motion to adjust the actuation point/dead zone to the full range.

Again, this is purely a guess.

This is interesting. I'd like to learn more about this so-called "learning." I've read about this, but everything has been so vague that I don't know what to think.

Is this learning an on-going thing, constantly adapting to changing conditions? Or, is it a one-time thing following an ECU reset? Is it set in stone until the next ECU reset, which for most of us might never occur?

I'd be grateful to anyone who could explain this to us, preferably with reliable URLs and references. I'd like to learn more.

Thanks.

[Gords_zenith]

The new drive by wire throttle pedals have a dead spot at initial depressing when the ecu had been disconnected with limited mileage on it. The computer learns the range of motion as you drive the car. As others have stated. In order to eliminate this dead zone to speed up the process of the computer learning the pedal range you can try the trick I posted earlier. It seemed to work for as I was experiencing the same thing as op is now. Nothing special about it, just that ecu needs to relearn after being disconnected or brand new with limited mileage. If your talking about the clutch engagement than that's something different and there are things you can do for that as well. But I wouldn't recommend it as it's not changing the leverage motion of the clutch and simply shortening the amount of travel, that if done incorrectly could lead to improper clutch actuation and premature clutch replacement. Anyways I hope this helps.

[SirBrass]

Originally Posted by Porsche

This is interesting. I'd like to learn more about this so-called "learning." I've read about this, but everything has been so vague that I don't know what to think.

Is this learning an on-going thing, constantly adapting to changing conditions? Or, is it a one-time thing following an ECU reset? Is it set in stone until the next ECU reset, which for most of us might never occur?

I'd be grateful to anyone who could explain this to us, preferably with reliable URLs and references. I'd like to learn more.

Thanks.

Just try the throttle pedal trick & profit ;-). You're not hurting anything.

Sent from my SCH-I535 using Tapatalk

[Porsche]

Originally Posted by SirBrass

Just try the throttle pedal trick & profit ;-).

LOL! Fair enough, I'm game. But, can you EXPLAIN it to me please, Sir? Note the questions above.

You're not hurting anything.

Well, of course not; it never occurred to me that it might.

Now, tell us EXACTLY what will it do? What will it CHANGE? Why do you imagine that it will change anything on my BRZ? How and why will it do it?

If you were to go outside right this minute and perform this magic on YOUR CAR, will your car run better than it did the last time you drove it?

How?

Why?

Help us! Inquiring minds wish to know!

[SirBrass]

When the ecu has been reset or is new, it doesn't know the full input range of the throttle position sensor, but has a general idea. This means it needs to learn the full range as the throttle is used. That is, over time, it learns what that particular sensor's range is.

Basic control loop.

Sent from my SCH-I535 using Tapatalk

[Porsche]

Originally Posted by SirBrass

When the ecu has been reset or is new...

Not applicable to my "old" 2013 BRZ, or to your car either, in other words.

Basic control loop.

VERY basic.

So, alas, my wonderful BRZ will not be even better still.

Okay then...

But you owe me, now, for getting my hopes up.

[SirBrass]

Just try it. And it is applicable to my brz, b/c I was getting road tuned on Monday.

Reset your ecu & try the pedal trick.

You're giving up too quickly.

Sent from my SCH-I535 using Tapatalk

[IronSean]

Originally Posted by Porsche

Not applicable to my "old" 2013 BRZ, or to your car either, in other words.

VERY basic.

So, alas, my wonderful BRZ will not be even better still.

Okay then...

But you owe me, now, for getting my hopes up.

What is will do is help make sure the ECU knows the full range of the Throttle pedal. This is because it's a drive by wire(electronic) pedal, and there's clearly some variance in the signals they send.

If you have a dead zone at the start of your throttle pedal, where pressing doesn't produce any throttle, I'd try it. If your pedal has adjusted to the point where it responds to all input within the inch of travel, then it's likely already adjusted itself on its own.

[Porsche]

Originally Posted by SirBrass

Just try it. And it is applicable to my brz, b/c I was getting road tuned on Monday.

Reset your ecu & try the pedal trick.

Do you get the feeling we're talking in circles? LOL!

Why should I reset my ECU? What will I gain? How? And why?

My car works perfectly. I never said it didn't.

You're giving up too quickly.

Giving up on what? My car works perfectly.

Resetting my ECU would mean limping around for some undetermined time before my car re-learned (what it already knows) and returns back to exactly where it is right now.

Get back. Get back, I say!

Don't touch my car, I tell you!

LOL!

[Formula Vee]

Lots of great information here.

I adjusted the clutch pedal a few days ago, and while it has helped tremendously with shifts, it's not the culprit.

I really don't feel it's a throttle dead zone either; the car just get bogged down if I am hard/fast with the throttle. Seems like it's running on three cylinders for a split second and then it jerks to life. And the sluggishness doesn't seem to match the torque curve/dip either.

If I take it easy on the throttle, and work up to full throttle just a tad slower, the sluggishness doesn't seem to show up quite as often. I'm not sure why that is.

I will probably try that pedal trick anyway, as I am all about speeding up the "learning process" of my new car.

[bcj]

Originally Posted by Porsche

LOL! Fair enough, I'm game. But, can you EXPLAIN it to me please, Sir? Note the questions above.

The throttle plate in the airstream (intake manifold) is an analog device. It has physical open and closed stop positions.
It's attached to a rheostat (another analog device - Throttle Position Sensor - TPS) that transmits an analog voltage value depending on where the throttle plate is at any given time.
You can think of it as the Volume Knob (mine goes to 11). They're the same type of device.
The TPS voltage is subject to manufacturing quality variability. Each individual TPS will produce slightly different values.

The ECU is a strictly digital device that needs to combine readings from the TPS along with a bunch of other analog signals to tell how the whole system is performing.
Typically, from a cold boot (no electrons) the ECU is programmed to expect a safe range of values from the various other sensors.
If it sees something outside those values it throws codes and the binky out of the pram.

In the case of the TPS when in range, the ECU has to narrow down the actual analog voltages produced when open and closed.
Usually initial ECU values allow for higher and lower values that cannot actually be produced - the dead spots - that it learns to ignore if those values are never recieved.


Thus endeth the Digital/Analog for this evening.

[Formula Vee]

Now that I have about 200 miles on the odometer, I think I've narrowed it down to poor performance at low revs. It just crawls when I try to move below ~2500 rpms, and then it jumps when I finally get there. I don't notice this in 1st, but it shows up in just about every other gear. Acceleration just sounds different and there's no pull.

Is that just the nature of the beast? Is that what everyone else gets when they try to get on the gas below ~2500? Is it a break-in thing?

People on here talk about shifting between 2-3000 rpm for "normal driving", and I don't know how they get by. I feel like I need to keep it above 3000 at all times lest I get super frustrated with the sluggish response.