Left foot braking, technical positioning question

[SammichLover]

MountainPass mentions here they now exclusively left foot brake. I've tried it a bit in the past and had some difficulties with it, and I'm trying it again now. Ironically not really the braking part and transition from accelerator to brake and back, that feel pretty natural quickly. I like it, can immediately sense a much smoother transition. There are still occasional 2-pedal warning beeps but if anything that's a positive in building awareness of WTF my feet are actually doing down there that I didn't notice before.

The issue is keeping in position in hard cornering and impinging on my operation of the vehicle controls. Note that I'm not ready for the step of installing a 5-point harness because, well, damn.

Part of it I suspect has to do with being used to having the left foot on the floorboard foot rest and effectively "standing up" on one leg on heavy braking and cornering. Having having the left foot out slightly to there means my thighs & hips sit wider as a base on the seat. Brining in the left foot to the left side of the brake pedal means that naturally gets narrower, to an extent.

I've done the moves of binding the lap belt buckle in place so it doesn't wiggle, and trigger the gravity lock on the B-pillar then move the seat forward & upward to tighten so it is locked in place. However I still feel floppy and worry I'm not as smooth and accurate as I could be on the wheel because I'm using it too much to keep myself in position.

Am I supposed to be using my core strength to try bring my legs closer to in line with my back, thus pressing on the three posts of my shoulder blades into the back of the seat, lower thighs into the front of the seat, and hip bone even firmer into the lap belt?

Is that what I should focus on at the gym, and to become instinctual and automatic during driving, to fix this? Or maybe I'm doing something off elsewhere is posture and positioning?

 

[Evoforce]

Why are you determined to drive this way?

 

[SammichLover]

Why are you determined to drive this way?

Because smooth is fast. Moving a single foot up and over and the up over and back down is time lost, and doing that quickly makes it hard to stop/slow at the right place to do a smooth transition. Regen braking helps some, but still you've got a gap where you're at a braking plateau w/only regen and could already be easing into friction braking. Same with transitioning from braking out to acceleration.

 

[Dana1]

Because smooth is fast. Moving a single foot up and over and the up over and back down is time lost, and doing that quickly makes it hard to stop/slow at the right place to do a smooth transition. Regen braking helps some, but still you've got a gap where you're at a braking plateau w/only regen and could already be easing into friction braking. Same with transitioning from braking out to acceleration.

This sounds like dreams of grandeur. A NASCAR driver might need split second reactions but I doubt your morning commute requires the same precision lol.

 

[Needsdecaf]

This sounds like dreams of grandeur. A NASCAR driver might need split second reactions but I doubt your morning commute requires the same precision lol.

He’s talking about autocross and track. Which he has done in the past.

Autocross especially can benefit from this. Much more than NASCAR, ironically.

 

[SammichLover]

I doubt your morning commute requires the same precision lol.

Some context to help you understand:

Don't have any video from the larger circuit track, yet, but am even trying to get out on Circuits of the Americas this year. I'll be doing no wheel-to-wheel racing though, not young enough and/or rich enough for that. Ironically it isn't as needed on the longer circuit tracks, even if it will help some with <edit> the transitions at the start of braking, in mid-turns, and exits.

 

[Needsdecaf]

People who have tracked the Model 3 more could comment, but to me, the Model 3 seat seems, ah, not so robustly made. Suspect that the seat and the seat hardware is likely moving around a bit. Also, the seat is pretty sparsely bolstered. So add those together and you’re really hanging on for dear life.

Have you tried one of those CG lockers that you attach to the seatbelt?

Another more radical idea...buy a race seat and swap it out at the track. Should fit in the trunk with the seats down, I bet. You will need to reset the airbag warning light each time of course.

 

[Magnets!]

So I'm curious about the 2 pedal warning beeps. Will the electronics allow you to apply the brakes while still on the throttle? Some cars will not.

It's definitely a worthy high performance driving technique and takes a while to build up the necessary finesse in the left foot so if you don't practice it on the street you'll never have it for the track.

 

[SammichLover]

Have you tried one of those CG lockers that you attach to the seatbelt?

Was about to pull the trigger on it. So far I've only simulated it with buckle flip and a bit of duct tape. I can get some pressure, but agree with the assessment of the Model 3 seat. It is better than it seems when you just sit in it but it isn't like, say, my friend's 993's seat which is like you're seating down into a bucket.

Another more radical idea...buy a race seat and swap it out at the track. Should fit in the trunk with the seats down, I bet. You will need to reset the airbag warning light each time of course.

That is pretty out there, but appreciate the spitballing.

I'm not familiar enough with SCCA rules yet but I'm guessing this would push me out of Street? That's a place I'd rather not go for AX. For now I'll stick a pin in that and call it "Plan B".

 

[SammichLover]

So I'm curious about the 2 pedal warning beeps. Will the electronics allow you to apply the brakes while still on the throttle? Some cars will not.

It's definitely a worthy high performance driving technique and takes a while to build up the necessary finesse in the left foot so if you don't practice it on the street you'll never have it for the track.

I don't know about RWD, but with AWD the Model 3 definitely cuts the power on the accelerator to some extent when both are pressed. However there is something there, because if you're at a stop and holding the brake if you press the accelerator and trigger the error you can feel the car surge up a bit and pressing against the brakes as long as you're holding the accelerator down. If you then release the brake you immediately move forward, but not with a burst. It seems to lag a bit before kicking up to the full power curve.

<edit> Initial impression is that it feels like T/C lag when you trigger the error. Not sure it will always be like that but pretty sure I'll want to avoid triggering the warning error.

I haven't tested behavior extensively yet. I've got an AX test/practice day next month, that's why I'm trying to get this all sorted out now so I'm ready to go live. Agree I need to be using this under more mostest environment ahead of time to get my brain there and ready for the stress of doing it at speed. Even a test day is limited in seat time to an extent.

<edit> Important, the first bit of travel on the brake pedal does not trigger the two-pedal warning. So you can have your foot on the pedal, as along as you don't go far enough to, I assume, trigger the friction brakes engaging.

 

[Stickers]

Auto crosser trick to get tight fit on stock 3 point belts...

Move seat back a little, strap in, pull belt tight, move seat up into position.

 

[SSonnentag]

I have always braked with either the left or right foot as the situation deemed best. For tight maneuvering, left foot braking is safest. For off-roading, left foot braking is definitely best. For normal street driving, I tend to stick with one foot driving, the right foot only.

 

[SammichLover]

Auto crosser trick to get tight fit on stock 3 point belts...

Move seat back a little, strap in, pull belt tight, move seat up into position.

Already did this, even a bit more than that. Sorry it wasn't clear from my initial post.

Moved the seat all the way back and down, flipped the belt buckle 360 where it'll still just buckle in. Also tried duct tape to get a bit more belt on belt pressure for less slip but that didn't seem to change anything. Then I yanked the shoulder strap to get it to lock in place at the right length (takes a few tries usually), kept it taunt while buckling in, and then tapped Restore for the seating profile. I've been doing this to an extent before but went even further here. Found I needed to adjust the steering wheel a bit. Pressed back enough the wheel had to come back, and I raised it a bit too which gave more room for the left knee to operate clearly under it not that gets a lot closer to center of the steering wheel.

Still I found I felt a lot more "tipsy" when I tried doing some mock high G turns (in an empty parking lot, not on the street). I tried forcefully readjusting my butt bones and left leg a bit to sit wider, and had some some success, however struggled to keep an even keel w/o leaning hard on the steering wheel for leverage.

Note: You probably shouldn't drive around a lot on streets like this. My understanding is that the air bag system makes assumptions about how much slack your seatbelt has and tries to time you flopping forward/sideways, with the airbag exploding out to meet you, for contact at a certain point in space. I could be wrong on this but my working assumption is this will make the restraint/crash system perform sub-optimal in keeping my innards in and unscrambled during an abrupt, unexpected alteration in my vector of travel.

 

[stickman]

Another more radical idea...buy a race seat and swap it out at the track. Should fit in the trunk with the seats down, I bet. You will need to reset the airbag warning light each time of course.

Perhaps not so radical. And depending on how far the track is you could swap it out at home. I probably would. I was looking into options (like the CG lock) and I talked with the guys at the local racecar shop and this is the solution he recommended, if one gets serious about tracking the car. You mount the race seat on a bottom bracket and side brackets, and its a matter of a few bolts and an electrical connector (or 2?) to swap. According to him having the lap belt tight helps a tiny bit but it doesn't allow you to relax like having proper side bolsters does.

 

[SammichLover]

Perhaps not so radical. And depending on how far the track is you could swap it out at home. I probably would. I was looking into options (like the CG lock) and I talked with the guys at the local racecar shop and this is the solution he recommended, if one gets serious about tracking the car. You mount the race seat on a bottom bracket and side brackets, and its a matter of a few bolts and an electrical connector (or 2?) to swap. According to him having the lap belt tight helps a tiny bit but it doesn't allow you to relax like having proper side bolsters does.

He looked at your car's seat assembly? I've not dealt with aftermarket seats before, so it is possible to have the quick mount to the vehicle's pre-existing track mounts? The tricky thing with the Model 3 compared to most ICE vehicles is a lack of access to the underside of the cabin floorpan. You've the battery pack in the way and dropping that out to access under the floorpan is a major operation.

 

[Dangerous Fish]

Does the 2 pedal warning and power cut happen in track mode as well as normal mode on the P3D?

 

[lolder]

Most all cars built recently cut power when brake is depressed. Most hybrids did also as did my 2010 Ford Fusion Hybrid.

 

[Magnets!]

Most all cars built recently cut power when brake is depressed. Most hybrids did also as did my 2010 Ford Fusion Hybrid.

I have no doubt that the cars you quote do indeed cut power, but performance cars typically do not.

 

[SammichLover]

Most all cars built recently cut power when brake is depressed. Most hybrids did also as did my 2010 Ford Fusion Hybrid.

Racing technique does still call on it at times, at least for RWD vehicles. Thus the question about Track Mode, which sadly I'm not in a position to test myself.

I'm not sure about AWD driving though, how much value there is in sending power to the wheels under braking, as with RWD it is about getting the nose down while doing more to induce oversteer. The P reportedly accomplishes this already in Track Mode. The D not really as much as just letting off to regen does help rotate and lighten and thus loosen the backend along with getting the front to bite and turn in.

 

[commasign]

Track Mode apparently has stronger regen. Wish they would allow this to be set with track mode off too. So, it would be High, Standard, and Low. Would make single pedal driving a little closer to two pedal driving.