P3D+ Acceleration

[kbecks13]

So I just noticed that my car's acceleration seems MUCH more pronounced when i go from 3-5MPH to 60MPH compared to going from 0-60. Does anyone elses P3D do this?

It honestly feels sluggish getting started from 0 and i'm not really sure why...

PS - The road is was on wasn't wet/dirty, so i dont think it was traction limited but that's my best guess at the moment.

 

[S4WRXTTCS]

So I just noticed that my car's acceleration seems MUCH more pronounced when i go from 3-5MPH to 60MPH compared to going from 0-60. Does anyone elses P3D do this?

It honestly feels sluggish getting started from 0 and i'm not really sure why...

Mine does the same thing at least in comparison to how my 70D felt. My 70D felt strong right off the line.

I'll probably take it to the track (or some empty place somewhere) to verify that it really does 0-60 in 3.5sec.

 

[bhzmark]

put a go pro on your tires and play it in slow motion and see if you aren't getting a little tire slip.

 

[kbecks13]

put a go pro on your tires and play it in slow motion and see if you aren't getting a little tire slip.

Good idea, i think it could be traction limited but i'm fairly surprised because the Pilot Sport 4S is pretttty darn sticky and the road wasn't in bad shape.

 

[TANGO SUKKA]

look at the width of the tires that come with 450hp cars, and then look at what tesla put on the p3d+. imo it's a huge limiting factor in the car. i'm looking to upgrade to 20x10's and probably run 265s on them.

 

[Shizzrock]

definitely not tire slip, it's just the way it launches. Maybe they're holding something back for later, but this car has no problem getting traction.

 

[kbecks13]

What's interesting is i swore the demo car was a bit faster and am wondering if others have noticed something similar. Or maybe i'm just getting used to it

 

[Gavyne]

You are anticipating the gforce. Sometimes when you are the one driving, and you stomp down hard to try to launch, your body and mind already knew what was going to happen. Try having someone else launch the car with you as a passenger, you'll feel it more because you are not the one stomping on the accelerator pedal.

 

[spectrum]

I have the same feeling with my X100D. It's the traction control kicking in and making sure you have enough grip. It artificially ramps up power. At 3-5 mph, you already have much more available grip so it is indeed quicker.

 

[Daniel in SD]

I have the same feeling with my X100D. It's the traction control kicking in and making sure you have enough grip. It artificially ramps up power. At 3-5 mph, you already have much more available grip so it is indeed quicker.

Grip is independent of speed. You can easily see this by braking times. It takes almost exactly the same amount of time to stop from 30-0 as it does from 60-30.
You can also tell the P3D is not traction limited by looking at braking times. It can stop from 60mph quite a bit faster than it can accelerate to 60mph.

 

[BrandonLive]

Grip is independent of speed. You can easily see this by braking times. It takes almost exactly the same amount of time to stop from 30-0 as it does from 60-30.
You can also tell the P3D is not traction limited by looking at braking times. It can stop from 60mph quite a bit faster than it can accelerate to 60mph.

Well, one exception which is sitting still vs moving. But also I suspect the physics of the differential contributes to a difference in grip when moving versus not.

 

[kbecks13]

I'm starting to wonder if it's brake hold and how it releases the car. I don't think i've ever had a good launch if brake hold was engaged when i punched it, anyone else?

 

[Daniel in SD]

Well, one exception which is sitting still vs moving. But also I suspect the physics of the differential contributes to a difference in grip when moving versus not.

Are you thinking of static vs. dynamic friction? Static friction is greater than dynamic friction which is why antilock brakes stop a car faster than skidding. Tires that are rolling experience static friction.

 

[D3xDt3Reaction]

I'm starting to wonder if it's brake hold and how it releases the car. I don't think i've ever had a good launch if brake hold was engaged when i punched it, anyone else?

I have wondered about brake hold’s impact on launches too. Need someone with a Dragy to stomp on it with and without brake hold to see what happens.

 

[Tummy]

I find our S accelerates faster when I turn on slip start. Maybe you can try that in your 3.

 

[BrandonLive]

Are you thinking of static vs. dynamic friction? Static friction is greater than dynamic friction which is why antilock brakes stop a car faster than skidding. Tires that are rolling experience static friction.

Sort of. Rolling resistance is based on static friction, and yes, static friction is (usually) greater than dynamic friction. ABS does a little more than that but that’s another topic.

From what I understand, there are a few factors at play with what the OP is describing. One factor is a shift in effective weight distribution once the car begins accelerating (which alters the normal forces and generally increases them on the rear wheels). Another is that the force resulting from a given engine power is inversely proportional to speed. At 0 velocity, the wheel has zero power and all the engine power acts on it as torque. Once you’re moving (and as speed increases), more of the power delivered by the engine is translated to wheel power instead of force on the wheel.

 

[BrandonLive]

I find our S accelerates faster when I turn on slip start. Maybe you can try that in your 3.

Right. Presumably this disabled or reduces the car’s traction control interventions (which cut power when slips are detected).

 

[Daniel in SD]

I don't see how people can think that the P3D+ is traction limited when the P100D runs the same tires and accelerates way faster. Also if you look at the acceleration plots of the P100D it accelerates fastest (highest G force) at lower speeds.
Weight transfer to the rear increases traction on the rear wheels and reduces it on the front so in an AWD car it seems like that would be pretty much a wash.

 

[mongo]

If the effect is real, it may be part of a "don't drive your car through the garage wall" software routine. A sudden flooring of the accelerator at a stand still may be a case the wrong pedal being pressed vs a launch.

 

[SigNC]

P3D doesn't launch nearly as hard from stop as a P85. It's super quick but it doesn't have that make you sick initial hit.