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Accelerate and brake

Discussion in 'Roadster' started by Dragon, Jun 28, 2011.

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How you drive the Roadster?

  1. Go-Kart style: Left foot for the brake, right foot to accelerate!

    0 vote(s)
    0.0%
  2. Single foot style: I don't need a left foot. At least not for driving.

    43 vote(s)
    87.8%
  3. Mixed: It depends if I'm on a race track etc.

    6 vote(s)
    12.2%
  1. Dragon

    Dragon Lightning Green Fairytale

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    I just wonder how you drive your Roadster.
     
  2. strider

    strider Active Member

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    All of the cars I've had until the Roadster have been manual transmission so I'm in the habit of right-foot braking to leave the left foot free for the clutch. Although i'm not that old I don't think it would be a good idea to try and teach me a new trick. I keep my left foot on the dead pedal.
     
  3. Doug_G

    Doug_G Lead Moderator

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    For track driving the two-foot method might actually make sense. You have to move your foot really quick back to the accelerator to balance the throttle for cornering. This is the one situation where the regenerative braking gets in the way a little.
     
  4. vfx

    vfx Well-Known Member

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    I (unfortunately) have found the solution for the pesky regen problem.
     
  5. Doug_G

    Doug_G Lead Moderator

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    :biggrin::confused::mad::rolleyes::biggrin:
     
  6. Jaff

    Jaff Active Member

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    After your experience with this brand of tire, there's no Falken way I'd use 'em! :biggrin::wink:


     
  7. SByer

    SByer '08 #383

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    I like to say I'm an asymmetric hyper-miler. I'll do the regen-to-near-zero thing all the time, but when there's a chance to stomp it...!

    I've gotten close a couple of times of making it all the way to work without hitting the friction brakes. Someday...
     
  8. zack

    zack Member

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    My dad was a driver's training instructor who used both feet on an automatic but taught using one foot to avoid trouble. I've never had occasion to use both feet even in go-kart situations... in fact, I must have had some strange go-karts because I've never had occasion to brake except for accidents or post finish line stopping.

    In the Tesla 2.5, I brake as little as possible and generally use the accelerator as a way to escape trouble. Nobody can see me, as far as I can tell. Maybe its because I chose every black option. 8^D
     
  9. daniel

    daniel Active Member

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    I never use the left foot on the brake. I used to have a manual car, and used it on the clutch. In my Roadster, which I have driven for exactly one day, and probably 70 or 80 miles, I find that I seldom need to use the brake at all. The regen is so strong. I'm still getting used to it. My Zap Xebra is freewheeling when both pedals are up, so coasting to stop signs is easy. I've used the brake on the Roadster a few times, other than when coming to a complete stop, but it sure isn't necessary much.
     
  10. Dragon

    Dragon Lightning Green Fairytale

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    I've had only manual cars since the Roadster. Don't know what to do with the spare leg now. :biggrin:
    For now the few meters I drove the car I used it to brake. But for doing this all the time the left pedal maybe is too near to the right, it would get uncomfortable I think.

    It's strange. No clutch, no gear shifting anymore. If the car wasn't so fast, I think it would be annoying with nothing much to do all the time.
     
  11. S-2000 Roadster

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    Finally, a plausible explanation for why the footwell is so exceptionally narrow in the Tesla Roadster: it makes the brake pedal closer to reach from either foot.
     
  12. Thumper

    Thumper Member

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    Learn to be comfortable left foot braking. It is much safer. When you get old, you will not hit the accelerator with your foot when you are trying to brake like people did with Audis a few years ago. Also in traffic, you can keep your left foot over the brake while continuing to drive thus saving precious fractions of a second in an emergency. I have been doing it for years. Since you are a practiced stick shift driver, the process will be easy because your left foot is already sensitive to how hard it pushes on things.
     
  13. strider

    strider Active Member

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    I'm sure it's a legacy Lotus thing - they had to squeeze 3 pedals in there for the Elise and when Tesla deleted one they just left the spacing of the other two to save costs.

    Perhaps we need to develop "heel-and-toe'ing" for the 21st century? Where you both brake and hold the accelerator at neutral (no regen).
     
  14. S-2000 Roadster

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    I was just joking ... more about how narrow the cockpit is rather than where the pedals are.

    I hope you're joking, here, too. Heel and Toe is only useful for shifting, and the Tesla Roadster has no gearing. There would be no advantage to avoiding regen to favor the heat-exchanger brake except perhaps for the 4-wheel nature of the disc brakes. That said, I still thought that I might catch myself heel-and-toeing out of habit...
     
  15. strider

    strider Active Member

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    I was half-joking. I know very little about hustling cars around a racetrack but I have done it a fair bit on a motorcycle. I can tell you that too much engine (rear wheel) braking can upset the balance of the bike entering a corner. So perhaps w/ the rear wheels regen'ing it could cause the back end to wag or step out - may be beneficial to be able to hold the accelerator at neutral throttle? I believe you were alluding to this w/ the 4-wheel disk brake comment?
     
  16. WarpedOne

    WarpedOne Supreme Premier

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    There is TC which shuts off regen immediately when rear wheels start to loose grip.
    IIRC regen is disabled every time you brake and turn hard to improve stability.
     
  17. Doug_G

    Doug_G Lead Moderator

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    If you're racing you want the TC off!!! Otherwise the car's dynamics go to pot if you hit a bump - accelerating OR decelerating.

    There's no doubt that TC works wonders in slippery conditions, but given recent experience I'm starting to think its disadvantages outweigh its advantages on dry pavement. Its behaviour on hard bumps leaves a lot to be desired.

    I've seen no evidence that regen is disabled under those conditions, except perhaps if you're braking so hard that ABS is active. In any case you shouldn't be turning while you are braking; the force you're using to decelerate takes away from the available turning force. You brake first in a straight line, THEN turn in.

    The regen is actually a minor problem on the race track. The brake prior to turning moves the weight onto the front wheels. Then you want to hold the throttle neutral while you turn. You have to move off the brake and onto the throttle very quickly yet very gently. It's okay once you're used to it, but even a very experienced race car driver took a few laps to get the hang of it.
     
  18. S-2000 Roadster

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    I have very little experience, so I'll just ask: Would it be possible to use the Tesla regen braking only during the straight-line deceleration, then quickly increase to neutral throttle for the turn?

    In other words, I guess my question has two parts: 1) Is the regen enough to slow the Roadster sufficiently before a turn, or are the disc brakes absolutely necessary? (I guess the answer depends upon the turn and the amount of speed reduction needed). 2) Which is more difficult: The transition from friction brake pedal to accelerator, or the Tesla-specific regen-to-neutral-acceleration?

    I find that I almost have to stare at the Roadster 2.5 kW gauge to see when I'm precisely neutral. I don't know if there is any effective difference, but I often naturally stop with still a slight amount of kW power to the wheels rather than precisely 0. I certainly get the results that I need from the car's movement, but I'm not sure that I'm literally reaching the zero-energy position for the throttle unless I look down and adjust using the visual feedback.
     
  19. Doug_G

    Doug_G Lead Moderator

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    Absolutely, yes, you can and would slightly alter your speed from time to time using regen. But most of the time you're flying towards a tight curve at high speed, and you need to get on the friction brakes hard.

    Disc brakes are absolutely necessary in most cases, if you're trying to make a good time around the track.

    Transition from friction brake to accelerator is more difficult, of course, but you need to do it. In fact it may be best to get into a rhythm and use the friction brakes every time.

    Of course if you're on a racetrack you're not looking at the power meter; you're using all of your concentration driving the car. You have to keep your eyes well ahead on the course to plan your optimal path through the curves. You're watching out for traffic (if applicable). You're keeping an eye out for flags from the marshals, road surface conditions, possible hazards, etc., etc.
     
  20. S-2000 Roadster

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    Yes, and I remember the instructions that you're not supposed to stare at an obstacle because that makes you more likely to steer directly into it. Instead, focus on the clear path and you're more likely to make it through. Wouldn't want to be staring at the kW gauge because there's no telling what you'd crash into.

    In all seriousness, though, I think it's way more important to be able to feel whether your vehicle is accelerating, decelerating, or neutral. Particularly, you want to be able to feel whether your roadster is resting on all four wheels, balanced, rather than leaning to the front or rear. It seems like it doesn't really matter whether the battery is actually feeding power or if there is literally no current flowing - the key is the force on the wheels.
     

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