Limited full acceleration

[shahryaran]

When I need to accelerate hard, I never press the pedal instantly. I always push the pedal with lesser rate. So it would take about half second or quarter a second to fully press the pedal.
I noticed that the car accelerate with very good torque from the beginning of the depress all the way to middle and almost to the end. But when the pedal reaches to the very end of its travel, the car did not have the same acceleration. But then when I left go off the pedal slightly from fully pressed down, the acceleration went back up again.
Has anyone had a similar experience?

2020 M3LRAB 42k
50% soc
Rainy

 

[GtiMart]

I don't quite understand your explanation but here are a couple of comments that might help.
If the wheels slip because they lose grip, the car will reduce power (traction control) and might reduce quite drastically if the steering wheel is turned (stability control). Although the car will try to add more power back to find the limit of traction, letting go of the accelerator and pressing it back will probably do it quicker. That might be what you have experienced.
You can look at obstacle-aware acceleration and turn it off to see if it helps.

 

[shahryaran]

There is no wheel slip.

 

[LoudMusic]

I wonder if it's just perception. Once the car is already moving your body becomes less aware of changes. But if you lift off the peddle the car will change to deceleration, so when you get back onto it there is new acceleration momentum. Your body will sense it differently.

 

[shahryaran]

The car decelerate when I push the pedal further down

 

[gearchruncher]

The car decelerate when I push the pedal further down

No it doesn't. Humans are just awful data recorders.

Get a datalogger for the car which shows throttle position vs motor current. You won't see what you think you are feeling. The car would literally be undrivable with what you decribe, going from negative torque at full throttle to full positive torque with just a bit less pedal position.

No throttle pedal in the world is linear- people like "sporty" pedals which have a lot of response in the middle of the travel. So it's very normal to detect more response in the middle and the top of the pedal to feel somewhat dead, but this is very, very different than a negative curve on the pedal.

Why are you pressing the pedal slowly anyway? This does not help the car in any way or reduce wear.

 

[LoudMusic]

The car decelerate when I push the pedal further down

Have you had someone else drive your vehicle to verify your experience? Have you driven another Model 3 and had a different experience?

 

[shahryaran]

No.

 

[Lindenwood]

There is no wheel slip.

You won’t notice screeching or fishtailing. The car will sense wheel slip in fractions of a wheel rotation and cut power for brief moments.

That said, I believe @gearchruncher’s assessment is likely. Indeed, like most cars, the pedal causes the car to produce maybe 75-80% of max wheel torque at only 50% throttle. So, the difference in acceleration between, say, 75% and 100% throttle might only be 5-10%, which is very hard to feel and may be perceived as not working correctly. Especially coupled with any normal wheel spin corrections at full throttle, you are likely logging normal operations as erroneous.

 

[804son]

These cars are a far removed from the old days of manual connection to a throttle plate. We have specific pedal mapping and throttle mapping software. It's not linear. If you want to accelerate hard, snap it down as fast as possible, let the traction control do it's thing. So long as you have a surface with good traction

 

[shahryaran]

These cars are a far removed from the old days of manual connection to a throttle plate. We have specific pedal mapping and throttle mapping software. It's not linear. If you want to accelerate hard, snap it down as fast as possible, let the traction control do it's thing. So long as you have a surface with good traction

I get better 0-60 not slamming the pedal. Measured by several equipments

 

[gearchruncher]

I get better 0-60 not slamming the pedal. Measured by several equipments

Post up your data please!

 

[shahryaran]

Post up your data please!

this is with pedal slamming

 

[804son]

So long as you have a surface that is not slippery, the M3 LRAWD w/ Boost or the M3P for that matter is not traction limited.

 

[shahryaran]

These cars are a far removed from the old days of manual connection to a throttle plate. We have specific pedal mapping and throttle mapping software. It's not linear. If you want to accelerate hard, snap it down as fast as possible, let the traction control do it's thing. So long as you have a surface with good traction

The burden of proof is on you.
You should provide proof of your claim.

 

[804son]

The burden of proof is on you.
You should provide proof of your claim.

Try the Search Button and NO the burden of proof is not on me

 

[MountainPass]

Strange thread for sure.

The reason that gas engines don't seem to have more power from ~75%-100% throttle is due to the throttle plate hardly being a restriction at that point. There is a cool feature in iRacing that allows you to select either a linear map (more akin to the EV experience or our 350Z racecar) or a butterfly-style map that reacts like a typical gas engine (lots of torque with minimal throttle % but not much difference near WOT). If you've driven a Miata on the track you know exactly what I mean!

My only guess with the limited information from OP is that there was some tire spin or a... misunderstanding of what is happening. It seems extremely unlikely that the car slows down when you go from 95% to 100% on the "go pedal."

 

[gearchruncher]

The reason that gas engines don't seem to have more power from ~75%-100% throttle is due to the throttle plate hardly being a restriction at that point.

I think you mean older cars with mechanical throttles.
All the DBW cars I have ever looked at the tuning tables for have the pedal mapped to a torque request, and the throttle plate angle is a result of achieving that torque, which could easily be linearized.
That said, they do stil tend to be mapped so the pedal has a lot of response in the middle and less at the top. This gets even worse in "sport" mode for cars where this often just makes the car feel "sporty" by mapping 90% of torque to 60% of pedal travel.

 

[MountainPass]

I think you mean older cars with mechanical throttles.
All the DBW cars I have ever looked at the tuning tables for have the pedal mapped to a torque request, and the throttle plate angle is a result of achieving that torque, which could easily be linearized.
That said, they do stil tend to be mapped so the pedal has a lot of response in the middle and less at the top. This gets even worse in "sport" mode for cars where this often just makes the car feel "sporty" by mapping 90% of torque to 60% of pedal travel.

Haha yes, good old-fashioned throttle cables! On our 350Z we have the DBW mapped to be linear ie. 50% throttle = 50% torque which is nice for the driver to handle 800hp.

 

[gearchruncher]

this is with pedal slamming

How is one graph of one case useful data when we were told it was faster with slow application proven by multiple measurement devices?
We'd need to see back to back tests, at same SoC and temperature and road surface, done enough times to prove a correlation.