The "Pedal Dance" testing

[SubiePig]

Originally Posted by renfield90

How aggressively did you trail brake? IMO it's the wrong way to drive the car...mostly because that induces ice mode. It's worse if you've got a big front bar.

I had more ice mode issues than most - pedal dance or no - until I started braking in a straight line. If I trail brake now, it's maybe 10% of the brakes or I just lift and use the tires to scrub speed.

Trail braking is the wrong way to drive the car.... Please tell me how using the maximum grip of the car by braking later through the entry of a corner while helping rotate the rear and bleeding off pressure as you increase steering angle towards the apex using the most of the cars front grip is in fact wrong.

[juliog]

Originally Posted by SubiePig

Going off the banking at TWS into turn one, about 130 down to about 60, I braked as deep as I was the session before trailing into the corner and ICE mode kicked in

So from 130 down to 60, at what speed did you actually start turning / trail-braking?

I don't do the pedal dance and just run with TC completely off, yet I see my dashboard flash when I trail-brake at high speeds and can feel the car trying to set me straight. My most recent instructor quickly pointed out that while some trail-braking in specific some corners is OK, I should do more of my initial braking in a straight line. I'm also apparently guilty of turning in too late and not sharply enough

[SubiePig]

Originally Posted by juliog

So from 130 down to 60, at what speed did you actually start turning / trail-braking?

I don't do the pedal dance and just run with TC completely off, yet I see my dashboard flash when I trail-brake at high speeds and can feel the car trying to set me straight. My most recent instructor quickly pointed out that while some trail-braking in specific some corners is OK, I should do more of my initial braking in a straight line. I'm also apparently guilty of turning in too late and not sharply enough

lite braking off the banking, brake hard and roll off into the corner.
[ame]http://youtu.be/Dkp4BhfvdHw[/ame]

[stugray]

SO am I understanding this correctly: Some of you have done the pedal dance and the car will STILL intervene when it starts to get tail happy?

[renfield90]

Originally Posted by SubiePig

Trail braking is the wrong way to drive the car.... Please tell me how using the maximum grip of the car by braking later through the entry of a corner while helping rotate the rear and bleeding off pressure as you increase steering angle towards the apex using the most of the cars front grip is in fact wrong.

Simple. If the car goes into ice mode when you trail brake and you go off into the wall...well that's not the fast way around the track, is it?

Drive what the car gives you. If the car doesn't let you get away with trail braking, change your driving style. Your other options are to modify/disable ABS or get a new car.

[CSG Mike]

Originally Posted by SubiePig

I will never do the pedal dance again, it almost resulted in a very bad weekend for me. I thought I would give it one more try in one of my time trial sessions this weekend. Going off the banking at TWS into turn one, about 130 down to about 60, I braked as deep as I was the session before trailing into the corner and ICE mode kicked in almost putting me off track. Later that session it happened again at a less high speed section of the track. Didn't do it again the next 5 sessions and never had a problem. I see the traction light flash on warm up lap sometimes, it might during the session I never look, but I never notice anything that would effect lap times.

Ice mode is driver induced error. Check back on your datalogs, and take note of your throttle and brake input in the section where you encountered ice mode.

Not using the pedal dance, IMO, is the same as leaving a driver aid on. While it's not stability control, it is a form of traction control, in the form of electronic brake distribution. The computer is forcing the car to maximize braking potential, rather than you, the driver, learning how to threshold brake.

[CSG Mike]

Originally Posted by SubiePig

Trail braking is the wrong way to drive the car.... Please tell me how using the maximum grip of the car by braking later through the entry of a corner while helping rotate the rear and bleeding off pressure as you increase steering angle towards the apex using the most of the cars front grip is in fact wrong.

I trail brake most corners; I use it to get more rotation on entry, so I can point the car the way I want it to be facing, and roll onto the throttle as I apex. The corners where I don't trail brake are corner specific, and I usually have a specific reason for not trail braking at those corners.

[Dezoris]

I would like some clarity here on this. To me threshold braking is that absolute edge before you enable a lockup event or in this case ABS activation.

I don't understand how ice mode could get activated with a functioning ABS system active.

The entire point of ABS is being able to brake past threshold on ABS and steer through the braking.

I got this mode only once during autox I broke way too hard and pushed straight into cones with loss of steering. How is this possible with ABS?

[dradernh]

Originally Posted by Dezoris

I don't understand how ice mode could get activated with a functioning ABS system active.

The entire point of ABS is being able to brake past threshold on ABS and steer through the braking.

I got this mode only once during autox I broke way too hard and pushed straight into cones with loss of steering. How is this possible with ABS?

OEM ABS software was not written for what track rats and autocross guys are doing. Ice mode has been around for twenty years and will probably be around for some time to come.

The old solution used to be (and still is) to swap out the OEM ABS for another, better system - which itself is an OEM system, either from the same or another manufacturer. Racers with money go Bosch Motorsport.

How those would integrate into the twins' systems, I have no idea, but based upon this text from the GT86-specific MoTeC M1 stand-alone ECU datasheet, I suspect it's a bit of a job:

ABS / VSC

• While this product uses some sensor information provided by
these systems (for example Wheel Speeds) no further interaction
occurs.

• Any operation of these systems that does not require engine ECU
interaction (for example VSC Disable Switch) will function normally.

I don't know how VSC is controlled but I'd guess that ABS is controlled via a stand-alone ABS controller/ECU.

[renfield90]

Originally Posted by Dezoris

I would like some clarity here on this. To me threshold braking is that absolute edge before you enable a lockup event or in this case ABS activation.

I don't understand how ice mode could get activated with a functioning ABS system active.

The entire point of ABS is being able to brake past threshold on ABS and steer through the braking.

I got this mode only once during autox I broke way too hard and pushed straight into cones with loss of steering. How is this possible with ABS?

Best explanation I could find in five minutes: http://forums.corvetteforum.com/1576900761-post10.html

There is a much better one I found, written by an actual engineer who worked on ABS systems, explaining some of the background math that goes into tuning an ABS system. The short story is you can tune an ABS system's parameters to reduce or - especially for motorsport ABS systems - completely eliminate the ice mode feature. I can't find that particular post right now though.

The bottom line is that the ABS parameters on the FRS are junk and you are better off learning to threshold brake correctly.

[renfield90]

Originally Posted by dradernh

OEM ABS software was not written for what track rats and autocross guys are doing. Ice mode has been around for twenty years and will probably be around for some time to come.

The old solution used to be (and still is) to swap out the OEM ABS for another, better system - which itself is an OEM system, either from the same or another manufacturer. Racers with money go Bosch Motorsport.

How those would integrate into the twins' systems, I have no idea, but based upon this text from the GT86-specific MoTeC M1 stand-alone ECU datasheet, I suspect it's a bit of a job:

ABS / VSC

• While this product uses some sensor information provided by
these systems (for example Wheel Speeds) no further interaction
occurs.

• Any operation of these systems that does not require engine ECU
interaction (for example VSC Disable Switch) will function normally.

I don't know how VSC is controlled but I'd guess that ABS is controlled via a stand-alone ABS controller/ECU.

Beat me to the punch. Basically there's ABS for racers and ABS for secretaries. We have the latter.

[Dezoris]

Originally Posted by renfield90

Best explanation I could find in five minutes: http://forums.corvetteforum.com/1576900761-post10.html

There is a much better one I found, written by an actual engineer who worked on ABS systems, explaining some of the background math that goes into tuning an ABS system. The short story is you can tune an ABS system's parameters to reduce or - especially for motorsport ABS systems - completely eliminate the ice mode feature. I can't find that particular post right now though.

The bottom line is that the ABS parameters on the FRS are junk and you are better off learning to threshold brake correctly.

Garbage, electronics, aids, assists make me limp. Thanks for the info on that, I guess I assumed it was more simple than this. As usual its not.

[Porsche]

Originally Posted by renfield90

The bottom line is that the ABS parameters on the FRS are junk and you are better off learning to threshold brake correctly.

So, would you recommend pulling the ABS fuse, then?

Note: I DISLIKE ABS, and would like to pull the fuse, but I worry about unintended consequences. The loss of EBD concerns me with a possible brake imbalance.

I'd be interested in your thoughts about this, Renfield.

I've spent most of my life driving cars without today's nannies, and the "loss" of them is not a concern to me.

ABS robs me of the life-saving ability to arrest any further change in direction. I WANT to be able to lock 'em up when I need to.

[fooddude]

Question about ice-mode:

Ok..so I read it happens in pedal-dance-mode during super fast pedal to braking and also deep in abs.

But..does ice-mode happen only particularly in pedal-dance-mode?

Or, does/can it happen also in regular non-pedal-dance-mode? Both, or either, vsc/trc on and off?

...in other words..is possible ice-mode a permanent fixture of the car, and can/possibly happen, regardless of what mode/setting or what you deactivate on the car?