Will the Digital speedometer have a fast refresh?

[Dzmitry]

Originally Posted by Blighty

Yes it would be safe to assume its from the JDM STI showcar, but I doubt there would be a difference.

Are there different final drives in the 86/BRZ across different regions? I thought that, apart from the change with the 16+ cars, they were all the same.

Again, I'm not an expert on this info, but I do know Europe had a much lower gear ratio offered, a 3.727. If you do the calculations based on this video we see, assuming the internal gear ratio's remained the same, the final diff would have to be 3.5! That's substantially lower than the 4.1/4.3 from the first gen. Certainly not impossible, as their reason for it in Europe was mpg improvements, but seems like a wild drop for U.S. spec.

Point is, we don't know. There could be plenty of reasons we see what we see in this video, so I'll just patiently wait for those specs to be released.

[Blighty]

Originally Posted by Kronk

0:59 .

This has some much better vision for spitballing. Early at where you have posted, and also at 2:29 it shows 4th at the rev limit doing 174kph.

First thing I've noticed is that it matches the OG 4.1 Final drive fairly close (actually more like 4.2).

BUT should we consider there being a difference between reported speed and real speed, as per automotive regulations dictating that all cars must report under the real speed.

If that is the case then a final drive could very well be the current and outgoing 4.3. But as its a testing car potentially they have a special version of the speed readout that is 100% accurate.

Of course its all under the assumption that they haven't changed the gear ratios themselves.

What I think is fairly clear though is that its going to be pretty much in the ballpark of the current car.

[Blighty]

Originally Posted by timurrrr

Here's CAN data.
On all the three graphs, green line is GPS speed.

As you say, that CAN data point does match the rear wheel speed.

If only I still had my car outside to do a burnout

[ermax]

Originally Posted by Kronk

0:59 .

Looks like the original 3rd gear with the 4.1 final. The speed is a little lagged it seems but very close.

[timurrrr]

Originally Posted by Kronk

0:59 .

Thanks for spotting that!
The video is 24 fps, and each km/h number stays on for 6 frames, so it looks very much like a 4 Hz refresh rate.
And that's the TRACK mode

Originally Posted by timurrrr

Between 0:41 and 0:43 (two seconds), the number changes 7 times. So ~3.5 Hz.

... so it didn't change much (if at all) from 1st gen.

Originally Posted by Blighty

This has some much better vision for spitballing. Early at where you have posted, and also at 2:29 it shows 4th at the rev limit doing 174kph.

First thing I've noticed is that it matches the OG 4.1 Final drive fairly close (actually more like 4.2).

BUT should we consider there being a difference between reported speed and real speed, as per automotive regulations dictating that all cars must report under the real speed.

[...]

Of course its all under the assumption that they haven't changed the gear ratios themselves.

I wouldn't overthink the regulations concern.
The current gen already very close to the real (GPS) speed, and I can't imagine why the new gen would be much worse.

We're also not talking about a Koenigsegg with bespoke transmission and final drive here.
I don't think they would spend too much time fine-tuning individual gear ratios, etc.
I'm pretty sure if they slap the '13 gears and final drive on the car with the same weight as '13 and 2.4L engine, it would be good enough in their opinion.
So if the 4th gear looks like it matches the '13 FD, then I'm just going to assume the gearing is the same as the '13-'16 gearing — until we have solid data about all the gears.

[Tcoat]

Originally Posted by Blighty

BUT should we consider there being a difference between reported speed and real speed, as per automotive regulations dictating that all cars must report under the real speed.

Where on earth did you come up with that? You have it backwards.

Australia - The speedo must not indicate a speed less than the vehicle’s true speed or a speed greater than the vehicle’s true speed by an amount more than 10 percent plus 4 km/h.

USA - must be equipped with a speedometer indicating vehicle speed in miles per hour and/or kilometers per hour. The speedometer must be accurate to within plus or minus 8 km/hr (5 mph) at a speed of 80 km/hr (50 mph).

Europe - no speedometer can read slower than the actual speed. Ever. On the high side, it's allowed to read up to 10% above the actual speed plus four or six kilometers per hour, depending on the type of vehicle.

Canada - In Canada, Transport Canada doesn't have any regulations on speedometer accuracy. LOL WE DON'T CARE!

[timurrrr]

Originally Posted by Tcoat

Where on earth did you come up with that? You have it backwards.

Probably just confused "less" and "more", no big deal.
It's a confusing topic to talk about two different speeds for the same object at the same time

[timurrrr]

Originally Posted by Tcoat

Europe - no speedometer can read slower than the actual speed. Ever.

Hmmm I wonder if we can find a way to prove that due to the 4 Hz refresh rate the speed is reported too low,
and file something like a class action lawsuit which would result in increasing the refresh rate

[Tcoat]

Originally Posted by timurrrr

Hmmm I wonder if we can find a way to prove that due to the 4 Hz refresh rate the speed is reported too low,
and file something like a class action lawsuit which would result in increasing the refresh rate

No no you can not. It is still accurate in the 10ths of a second. This is more than enough for near everybody except the most fanatical of gauge watchers.

[nextcar]

I shudder to think how some of the people in this thread could ever have coped with a good old cable driven speedometer, where the needle position was governed by how frequently an off center peg was hitting against the spring loaded needle...

How did we ever survive? Oh the humanities!

[timurrrr]

Originally Posted by Tcoat

No no you can not. It is still accurate in the 10ths of a second. This is more than enough for near everybody except the most fanatical of gauge watchers.

Who just said "Ever."?

[ermax]

Originally Posted by timurrrr

Hmmm I wonder if we can find a way to prove that due to the 4 Hz refresh rate the speed is reported too low,
and file something like a class action lawsuit which would result in increasing the refresh rate

Just maintain a consistent speed for a fraction of a second and BAM, you have your answer. :P

[Red-86]

I am amazed at angst over digital speedo refresh rate. Wow. It’s there to make sure you don’t get a speeding ticket. You really shouldn’t be staring at it for long (because that is taking your eyes off the road), and for the quick speed check they are designed for, a normal refresh rate where each number is quickly parsed with a brief glance is better and safer than a faster but unintelligible whirring refresh rate that is useless at anything but a constant speed.

[Tcoat]

Originally Posted by nextcar

I shudder to think how some of the people in this thread could ever have coped with a good old cable driven speedometer, where the needle position was governed by how frequently an off center peg was hitting against the spring loaded needle...

How did we ever survive? Oh the humanities!

And could constantly fluctuate in a 10 MPH arch!