GR Yaris Issues when driving on slippery surface

Went yesterday to enjoy our blizzard and 10-20cm of new snow.
Noticed the common sympton of when driving on very slippery surface - feel like car tends to become occasionally front drive biased.
Did not get any errors or such, but it was easily noticeable. Drove sport mode (as always).

Maybe ECU is saving the rear clutch pack occasionally and pushing more power to front or what might be the case?

Generally I find the GR all wheel drive most wonderful, but this little quirk is irritating. Luckily it happens very seldom.
 
Michael Knight said:
Went yesterday to enjoy our blizzard and 10-20cm of new snow.
Noticed the common sympton of when driving on very slippery surface - feel like car tends to become occasionally front drive biased.
Did not get any errors or such, but it was easily noticeable. Drove sport mode (as always).

Maybe ECU is saving the rear clutch pack occasionally and pushing more power to front or what might be the case?

Generally I find the GR all wheel drive most wonderful, but this little quirk is irritating. Luckily it happens very seldom.
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Drive to Jyväskylä and tell Jari-Matti he should recalibrate the said ECU.
 
Probably not a fair comparison but it's very cold here by UK standards and track 50/50 mode seems to be the best for the ice / snow here and keeps it sensible - e.g. can do most of the usual shenanigans and not lose the car.

A bit of slide at the back but no traction problems at all. Fab car.
 
Noticed a bit more understeer in tight turns this morning, but then it was -8°C
 
Michael Knight said:
we also have HSUKD called lift off, seems to work well too
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Apparently, some have complained about the HSUKD engaging itself when all they wanted was to slow down, catching them off-guard. :ROFLMAO:

Full of character this car! And, at times, seems to have a mind of its own.

I know its platform derives from joining a different front and rear one and that the rear is set up to run 1% faster than the front. However, there are moments when I could be convinced that the rear is a totally separate car, driving in a different direction at a different speed. 😊
 
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Spirited said:
Apparently, some have complained about the HSUKD engaging itself when all they wanted was to slow down, catching them off-guard. :ROFLMAO:

Full off character this car! And, at times, seems to have a mind of its own.

I know its platform derives from joining a different front and rear one and that the rear is set up to run 1% faster than the front. However, there are moments when I could be convinced that the rear is a totally separate car, driving in a different direction at a different speed. 😊
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it has its quirks surely. Most of the time its really solid and stable, but it can bite..
 
Here in the UK it’s pretty cold at the moment, temp around -1*C today, no snow but the roads are dirty, damp and quite slippery. Today I had two small ‘events’ both at low speed and as I was accelerating away from roundabouts. Not really pushing, slow in but moderate throttle as I finished the corner. It felt like the car rotated around me and more than I was expecting, just a touch of unexpected oversteer and then it took off up the road. I was in normal mode so a slight surprise, I’ll try and explore further if I can find somewhere safe to experiment.

Circuit pack, standard geometry and new Michelin CC2 tyres if anyone curious. The tyres do feel really good in these conditions I have to say.
 
grydoc said:
Here in the UK it’s pretty cold at the moment, temp around -1*C today, no snow but the roads are dirty, damp and quite slippery. Today I had two small ‘events’ both at low speed and as I was accelerating away from roundabouts. Not really pushing, slow in but moderate throttle as I finished the corner. It felt like the car rotated around me and more than I was expecting, just a touch of unexpected oversteer and then it took off up the road. I was in normal mode so a slight surprise, I’ll try and explore further if I can find somewhere safe to experiment.

Circuit pack, standard geometry and new Michelin CC2 tyres if anyone curious. The tyres do feel really good in these conditions I have to say.
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You touch upon the next big challenge for real world driving, and that's when grip varies.
And it's usually into, on and out of crossings it can be extra slippery. For me this has been a big subject, wanting to enjoy a car winter time, but without crashing obviously.

We've already touched on lift-off and how that can make the car unstable. Something similar can happen on the throttle. I've you are familiar with the 'Mustang leaves car meet crash' phenomenon, this is basically powersliding that is uncontrolled. The slide is initiated not on balance but on overpowering traction. This can happen by stomping the pedal, or as here, by sudden reduction in grip. If the car was already yawing in a turn, this yaw will be reinforced, even on the GRY and despite awd - laws of physics. It is easy to loose control if the wheel speeds are much higher then road speeds as letting off throttle will both introduce weight transfer while, a specially when really slippery, the wheel spin doesn't necessarily stop when you think it will. Even if you know it is slippery, making a controlled slide can be hard as the turbo lag and boost coming in can make it hard to fine-tune the wheel slippage.

The solution to all this? Well other then trying to find the grip limits on braking or handbrake or on balance in controlled forms, the solution is again spelled left foot braking. With it you can immediately and simultaneously even when still on throttle, control wheel speed and stabilise the car.

As left foot braking requires a sensitivity in the left foot that usually isn't there on the clutch kick reflexes, this means a lot of practice. Practice in a safe place and with safe guidance if necessary, and if you get a hang of it, keep it up in dialy driving. I know I lose the 'touch' if I don't regularly practice it. In the GRY it is a joy that can be had on every drive. And I forgot who but remember someone of the GRY development team stating that left foot braking is key to mastering the GRY.
 
That or keep esp or at the very least, Expert mode ON as it, if not completely save ones *ss, at least helps in the right direction.
 
Would be fun to hear the story with the "expert" mode - was it implemented afterwards when they noticed the snappiness of the car?
Nice story to tell
 
'Expert' seems to me very similar to ESP sport mode, MDM mode etc etc with other manufacturers. You can loose any car and have it 'snap', with the GRY it just happens at higher speeds due to high traction and grip levels...
 
Left foot braking in my car cuts engine power as it does in most modern cars. It does perhaps allow a little more than your average econo box but it does cut the engine.
 
Yaris146 said:
Left foot braking in my car cuts engine power as it does in most modern cars. It does perhaps allow a little more than your average econo box but it does cut the engine.
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It does indeed when going straight on doing it very obviously. But out and about, all systems off, drifting every single roundabout and bend in the snowy winterland, it hasn't interfered, ever. Neither has it interfered on very twisty backroad runs.
LFB works (for me at least).
 
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I would expect it always happens but I’m not sure what the timescale is. 2 sec maybe 3? Hasn’t happened to me often but It has where I’ve dragged it because I don’t want the front to pop up.
 
Dragging isn't exactly the context we're talking about here, there yes it would probably cut off the engine.
 
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