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I see. Then let's join both ideas.
You get a switch (or lever) for setting how much regen (and alas braking) you get from accelerator pedal only.
On the brakepedal you only get an additional potentiometer for sensing its position - more depressed gives you even more regen on the rear wheels. Front/rear braking ratio is set more to the front. I see no big changes in brake subsistem required for that.
I just want to get as much energy back as possible. Don't want to heat the climate.
Wow! This sounds like it should remain as the long term (final) solution. Having a single gear would also allow greater passing response at normal highway speeds. I believe that the purchasers would be willing to forego any post purchase transmission replacement with this as the solution.
Maybe Tesla can be convinced to stick with this and perhaps add brake regen into the next revision.
As a driver who revels in the process of revving out a motor and doing a minutely choreographed flurry of arm and leg motion that end in a “slamming” of the accelerator, the loss of that visceral right hand stick motion of pushing, pulling and all around moving those spinning gears to their next position as quickly as possible leaves an empty place in the sports car experience... The idea of paddle shifting was always cool (my dad makes them for specialized racing) since the driver is still calling the shots. But the idea of automatics making the gear decisions for me has always been a bore. My SUV has the barely acceptable Tiptronic feature that I often use to get me out (and into) jams.
Now the Roaster will have a chrome plated vertical reminder of those good shifting times sitting in the middle of the car. Sort of like a photo of an old love permanently stuck to your windshield. Come on, the idea of a 15-inch SWITCH is lame. If I wanted a stick that was 100 times bigger than it needs to be then I would have Chuck Barris make me a car:
http://www.kustomink.com.au/TalesOfTheRatFink.html
And crank up the tunes:
http://www.amazon.com/Hot-Rod-Hootenanny-Gasser-Weirdos/dp/B000EMGJ1I
All of the P-R-N-D-L-S--E-T-C can be taken care of with a rotary knob on the center console.
http://electronicdesign.com/Files/29/8246/Figure_02.gif
I realize Tesla is (was) trying to keep that “classic sports car feel” but seriously a non-shifting shifter? What a waste of space in what is already a tiny car. It’s an electric car. Embrace that. Love that. Celebrate it. And loose the tail already, we have evolved.
Now the Roaster will have a chrome plated vertical reminder of those good shifting times sitting in the middle of the car. Sort of like a photo of an old love permanently stuck to your windshield. Come on, the idea of a 15-inch SWITCH is lame. If I wanted a stick that was 100 times bigger than it needs to be then I would have Chuck Barris make me a car:
http://www.kustomink.com.au/TalesOfTheRatFink.html
And crank up the tunes:
http://www.amazon.com/Hot-Rod-Hootenanny-Gasser-Weirdos/dp/B000EMGJ1I
All of the P-R-N-D-L-S--E-T-C can be taken care of with a rotary knob on the center console.
http://electronicdesign.com/Files/29/8246/Figure_02.gif
I realize Tesla is (was) trying to keep that “classic sports car feel” but seriously a non-shifting shifter? What a waste of space in what is already a tiny car. It’s an electric car. Embrace that. Love that. Celebrate it. And loose the tail already, we have evolved.
tonybelding
Active Member
He wasn't asking for actual braking from the accelerator pedal, was he? That wouldn't make sense.
No. Regen goes on the accelerator pedal, braking goes on the brake pedal. There is no reason to mix up these functions and every reason to keep them separate and distinct.
I see. Then let's join both ideas.
You get a switch (or lever) for setting how much regen (and alas braking) you get from accelerator pedal only.
On the brakepedal you only get an additional potentiometer for sensing its position - more depressed gives you even more regen on the rear wheels. Front/rear braking ratio is set more to the front. I see no big changes in brake subsistem required for that.
I just want to get as much energy back as possible. Don't want to heat the climate.
How much have you driven a vehicle that is designed like this?
I own one in the form of an 06 Lexus. Toyota has invested 100s of millions and many years of development and this vehicle still has the worst braking profile of any vehicle I have owned. It is acceptable for the type of vehicle but nowhere near acceptable for a sports car. The auto magazines would absolutely rip it to shreds over this.
I see. Then let's join both ideas.
You get a switch (or lever) for setting how much regen (and alas braking) you get from accelerator pedal only.
On the brakepedal you only get an additional potentiometer for sensing its position - more depressed gives you even more regen on the rear wheels. Front/rear braking ratio is set more to the front. I see no big changes in brake subsistem required for that.
I just want to get as much energy back as possible. Don't want to heat the climate.
Yes, that is the way I would want it to ideally work. I don't know for sure, but I think Tesla may have needed to leave the brake pedal alone so as not to open a whole other can of recertification worms. I think the ABS system is tricky and if you mess with it at all there could be complications.
This sort of compromise probably doesn't affect driving dynamics, but could hurt efficiency and friction brake pad life a bit. This is all just speculation now. I don't really know what they are doing nor what changes they might be planning for the future.
My wife's hybrid highlander has that as well, but I find that the brake pedal action is acceptable. My Lexus is ICE only, and has a conventional braking mechanism but has worse brake pedal feel than the highlander.
Pedal feel can vary from vehicle to vehicle. The condition of the brake rotors, pads, fluid, vacuum diaphragm, and adjustments on pedal travel can all play a part. Sometimes a minor turn of a screw on the pedal settings can make a big difference. I used to have a vehicle without power brakes (no vacuum booster) and the pedal feel was so much more linear and predictable. Anything you add (Vacuum boost, ABS, regen, whatever) has the potential to corrupt the pedal feel.
Yeah, I was never asking for friction brake action without pushing the brake pedal. It was all about how much eMotor regen gets activated when you let your foot off the accelerator pedal. I would want more on hills, and less when cruising on the highway. Overall, though I would probably want fairly strong regen always available, but some people would want none (so it coasts like an automatic when you let off of the accelerator pedal).
I have plenty of fond memories of orchestrating the "perfect shift" during enthusiastic driving, but personally I think it is time to "evolve" to the next level where you put more focus and concentration on other things.
The eMotor torque curve (line!) says that shifting is an old habit that we don't need to keep. You will get all the benefits of manual performance without the chore (or joy) of shifting depending on how you look at it.
Keeping both hands on the steering wheel at all times is probably a safer practice anyways.
Kardax
Member
Though it seems like Tesla is going to stick with a single-speed system for now, the door remains open to switch back to a two (or more) speed gearbox in the future if they can make it work. Otherwise, the tachometer could be considered vestigial, too...
-Ryan
-Ryan
SByer
'08 #383
I've been a stickie all my life. I think nothing ruins a great car more than sticking a slushbox in it. I think the lack of engine breaking in automatics is one of the lamest things ever, and leads to some bad driving habits, especially in the mountains. Automatics just suck - they're always in the wrong gear (the one you just needed a second ago instead of the one you're about to need).
Before my drive, I was worried a little about the lack of a clutch or real gears. Now? I'm totally stoked waiting for it. Why? Because sticks are there to compensate for the (now we know) really lame, narrow torque bands of the ICE. And the ICE gives you all sorts of queues that it's time to switch.
With the Roadster, that's simply not the case. You push the pedal, it just goes. Don't need to switch gears to get into the meat of the torque, don't get chugging or whining or turbo sucking. The queues to shift are gone, the need to shift is gone. It's just happy.
But, I do want the stronger regen from 1st gear in transmission 1.5. It was quite strong and perfect for the twisties.
Before my drive, I was worried a little about the lack of a clutch or real gears. Now? I'm totally stoked waiting for it. Why? Because sticks are there to compensate for the (now we know) really lame, narrow torque bands of the ICE. And the ICE gives you all sorts of queues that it's time to switch.
With the Roadster, that's simply not the case. You push the pedal, it just goes. Don't need to switch gears to get into the meat of the torque, don't get chugging or whining or turbo sucking. The queues to shift are gone, the need to shift is gone. It's just happy.
But, I do want the stronger regen from 1st gear in transmission 1.5. It was quite strong and perfect for the twisties.
Where did I suggest that? But regen IS braking, though without using the brakes.
Once again: Regen IS braking = actively removing kinetic energy from the car. I just suggested that maximum available regen is only applied when you are also pushing the brake pedal hard. Why? Because the deceleration you get would be huge - almost same as maximum acceleration from 0 to 60. Going 60mph and apply max regen - puf in 4 seconds you are standing still (actually it would take a little more than 4 seconds because of traction issues). You only want to do that when there is an emergency.
But I can understand there would problems in synchronizing both systems (classic brakes and motor braking) not get into troubles. Lets say you have very worn brake pads so maximum braking force is severely reduced. When you brake hard, you want more braking in the front wheels. With worn brakepads and regen you get more braking force in the back - stability issues abound.
tonybelding
Active Member
It seems to me that regen and conventional braking are two different functions. They are different dynamically and there are different times when you would want to engage them. Regen is a function of the motor and belongs on the motor-control pedal. Braking belongs on the brake pedal.
Regen may be like braking, but in my mind it is more equivalent to down shifting with strong engine braking while putting gas back into the tank. With a good regen setup and any amount of road condition awareness, the brake pedal can pretty much become something used for emergencies and to hold the vehicle in place when stopped.
This my sound far fetched but I believe I could practically count the times on my fingers that I have actually used the excellent Brembo brakes on my Vectrix maxi-scooter for anything other then holding myself in place when stopped on a grade. I thought that it would take a while to get used to twisting the throttle backward to stop, but it was totally intuitive from my first ride on and I totally love not needing to grab the brake handles all the time.
This my sound far fetched but I believe I could practically count the times on my fingers that I have actually used the excellent Brembo brakes on my Vectrix maxi-scooter for anything other then holding myself in place when stopped on a grade. I thought that it would take a while to get used to twisting the throttle backward to stop, but it was totally intuitive from my first ride on and I totally love not needing to grab the brake handles all the time.
TEG said:
And on my wife's highlander hybrid is has PRNDB
At first I thought the B would be like E on the Ranger to offer enhanced regen (simulated engine braking), but after reading some info on the net I found that it is in fact REAL engine braking on the Toyota hybrids. It tells the transmission and ICE controller to put a lot of vacuum on the ICE and switch the CVT to gear it for stronger engine braking.
The idea there was that you could be going down a long hill, and the battery pack could get all full from regen, so you need some other way to slow down besides the friction brakes. Personally I would have rather just have B mode be enhanced regen and have some sort of "energy bleedoff resistor/heatsink" to slow you down, but Toyota decided to give the driver a way to force more real ICE engine braking if needed.
(By the way, the Toyota dealer didn't really know how B mode worked, and just said "never use it")
With a pure BEV you are unlikely to "run out of regen" unless you charged to full at the top of a big hill. With hybrids you can more easily get into a situation where the ICE/generator filled the pack, and you don't have any more battery capacity to capture the regen energy (so some regen systems will refuse to activate).
WarpedOne, I don't think the regen is quite the inverse of acceleration. I don't think 0-60 in 4s automatically means you could regen from 60 to 0 in 4s. Among other things (as was mentioned) braking shifts weight onto the front wheels. Under heavily acceleration the Roadster will have much more traction on the rear wheels, but under heavy braking the bias will shift towards the front wheels. Also, I heard the regen tends to be disabled below a certain speed (although I am not sure the exact reason).
This has been debated upside down and sideways before, but I tend to disagree. I think a blend of regen and friction braking belongs on the brake pedal and a blend of acceleration (positive torque) and deceleration (negative torque) belongs on the accelerator pedal.tonybelding said:
In some ways it boils down to drivers used to auto trans vs manual trans.
The manual trans sports car guys (like me) want simulated engine braking (regen) while in gear just by lifting off of the accelerator pedal.
The auto trans people want to let the car "coast" when you let off of the go pedal. If Tesla offers modes for the auto trans people then they won't be getting the (efficiency) benefits of regen if all they ever do is accelerate, coast, or use the friction brakes. I suspect that Tesla has kept the regen away from the friction brake pedal, so they really need to do all they can to allow as much "off throttle" regen as customers can stomach. If it means a switch (or vestigial shift lever) to let you select then so be it.
(That is my opinion at least)
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