Disabling VSA via “Pedal Dance” vs. +R with button differences?

[keller]

Indeed. Pedal Dance = Agile Handling Assist off too. This is the way to go on track.

This is news to me: it says it only uses the front brakes!

I believe the agile handling assist improves lap times. Like trail braking makes you faster even though you are breaking, the ability to slightly change the braking force distribution with the steering wheel seems like a good idea when cornering and trail breaking.

Here's a pic from the fk8 service manual that might be of interest:

VSA Control in this table refers to the understeer and oversteer assist.

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[Geezer]

So it engages the front brakes not the rear? And for how long? A split second at initial turn in and only to induce rotation not to effectively kill a spin like vsa would do? I've driven the car plenty in plus R now with long hold in autocross setting and didn't really notice any artificial behavior.
Would be interested to know the influence of a rear sway bar as it comes to agile handling assist. If the computer is "assisting" to induce the rotation based on whatever algorithm does a rear bar and the improvement in the immediacy of said rotation effectively cancel agile handling assist?

 

[Geezer]

Tested this out at the track a couple weeks ago - Pedal dance will completely disable traction and stability control. +R mode with traction and stability control “off” will still engage the rear brakes to help rotate the car around corners, resulting in accelerated rear pad wear. Basically, same as the FK8.

The car won’t rotate as much with the pedal dance, but your brakes will last longer with less heat in the system and much less wear to the rears.

Did you check lap times? Any other observations between the two? If the handling assist is so well integrated where it is almost indiscernible and your average driver takes it for granted as normal behavior I could see maintenance mode actually feeling less natural.

 

[Geezer]

The pedal felt different, almost as if it didn't quite have ABS. It's not conclusive as there were other variables at play. I did my first run in +R mode and it was way too bumpy for this particular venue (the first time I've encountered that, but this was a different venue than the other 3 places I've competed in this car so far), so that may have attributed to that feeling (+R hasn't been too bumpy in the 11 events before this). By no means did it feel like something was wrong, dangerous or that it didn't have ABS; I would have locked up a couple times. I'm going to try it again at my next event this coming weekend. It's only a week from this past Saturday's event and at a different location, so an A-B comparison should still be fresh in my mind.

I was recording video through the LogR app, but for the life of me can't get the LogR data to sync with the video. If I could, I would have some data to look at (brake pressure for one) and see if it was just in my head, which I'm leaning towards at this time.

I got the overlay working and don't believe that the handling assist would show up as a manual brake input.

 

[keller]

So it engages the front brakes not the rear? And for how long? A split second at initial turn in and only to induce rotation not to effectively kill a spin like vsa would do? I've driven the car plenty in plus R now with long hold in autocross setting and didn't really notice any artificial behavior.
Would be interested to know the influence of a rear sway bar as it comes to agile handling assist. If the computer is "assisting" to induce the rotation based on whatever algorithm does a rear bar and the improvement in the immediacy of said rotation effectively cancel agile handling assist?

The fk8 service manual says it's a feedforward control on the steering wheel angular velocity. Since it's a feedforward, it will command the brakes and help rotate the car no matter what mods you made to the vehicle dynamics. I suspect the steering feel of the car wouldn't feel as direct as it is without the assist.

The other 2 assists (oversteer and understeer assists) also apply the brakes (outside and inside, respectively). But these assists are feedback control laws, they constantly monitor the vehicle yaw rate, lateral acceleration and steering wheel angle to decide what to do. These would be affected by a RSB or any other methods to increase rotation.

 

[Modular Cal]

I got the overlay working and don't believe that the handling assist would show up as a manual brake input.

I was referring to the braking feeling different after putting the TC/VSC in maintenance mode, not necessarily looking at how the VSC effects the brakes. I was curious if that mode did more than just disable TC/VSC and if any data would show differences in how I was braking. I think it's just the bumpy course that caused the awkward brake feel (it's a parking lot where the car haulers park at a dragstrip, so there are lots of valleys), but it doesn't hurt to be sure there isn't an problem.

How did you get the data to overlay? That may be a separate thread or at least a private message. I don't want to hijack this thread.

 

[Geezer]

Yeah I posted a thread with the overlay if you have questions dm me.
I just tried the pedal dance per posted instructions super simple will for sure do it at my next event. You guys just turn car off and turn back on to put it back in regular mode correct?

 

[Icehawk]

I think if you hit the TC button again it will turn everything back on. Would love an arduino commander so you could just hit a button and it would send the "dance" to the ECU. That and a knob to adjust damping...

I will say for street driving the various VSA controls are pretty transparent, I can still spin the tires or get it to slide (understeer) with it full on - my wife's '13 Si has the type of TC that cuts in like crazy and makes me push the button whenever I get in, with the CTR I don't bother.

 

[Pekingduck]

Put your foot on the brake and hold
Turn off traction control (hold for a second until it beeps for future reference)
Turn on traction control
Pull up on the e-brake
Take your foot off the brake
Turn off traction control
Turn on traction control
Put your foot on the brake and hold
Turn off traction control
Turn on traction control.

Haha your post help so much because I couldn’t find out how to turn off

 

[johnloov]

I agree; the brakes feel better with pedal dance. I need to do more testing but the brakes feel more responsive to me everytime I enabled pedal dance vs type r long press traction off.

Not sure what’s going on but there seems to be better bite or response with pedal dance, then the r traction of mode, and default mode seems to be the least responsive.
Seems like the brakes are already slightly engaged all the time.

Especially on canyon carving the default traction controls on the brake pads feel like they are always touching as I go to brake feels like the calipers are already on the brakes a touch and it’s like a even transition into harder braking.

With pedal dance, it feels like the brake calipers are fully retracted and so when I go to brake - it feels like a gap then it bites… which feels superior to me… this I’m sure of on my car. Running Castrol SRF fluid.

Anyone else feeling this same brake pedal sensation????

Pedal dance - better bite? And calipers fully retracted before braking vs. other modes???

I’m gonna find out soon at Laguna Seca.

The pedal felt different, almost as if it didn't quite have ABS. It's not conclusive as there were other variables at play. I did my first run in +R mode and it was way too bumpy for this particular venue (the first time I've encountered that, but this was a different venue than the other 3 places I've competed in this car so far), so that may have attributed to that feeling (+R hasn't been too bumpy in the 11 events before this). By no means did it feel like something was wrong, dangerous or that it didn't have ABS; I would have locked up a couple times. I'm going to try it again at my next event this coming weekend. It's only a week from this past Saturday's event and at a different location, so an A-B comparison should still be fresh in my mind.

I was recording video through the LogR app, but for the life of me can't get the LogR data to sync with the video. If I could, I would have some data to look at (brake pressure for one) and see if it was just in my head, which I'm leaning towards at this time.

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