The other day, some guy (he looked kind of scruffy, so he might have been an auto mechanic or a homeless guy, for all I know) told me about some gal giving him a ride in a fancy car (I forget the brand/model) that has all-wheel steering! He said she could take a sharp corner at 60 mph. Maybe he was exaggerating, but the point was that supposedly all-wheel steering gives much better handling in turns. When I consider the possible consequences, I've decided not to take my Roadster to the track to try to find out what it could do. I love driving electric, and I enjoy flooring it up to the speed limit, and I like the way it takes curvy roads. But I'm not a race-car driver.
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frequencydip
Sig 100 - #52
Regen causes heat in the motor, so either heat the brakes or heat the motor, its beter to heat the brakes as thats what they are designed to dissipate heat more than the motor is.
Traditional brakes convert roughly 100% of your kinetic (movment) energy to heat.
Regen brakes convert about 80-95% of your kinetic energy into chemical stored energy in the battery. The rest is dissipated into heat. Which is easily dissipated by the motor and battery cooling system.
Regen produces much less heat.
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frequencydip
Sig 100 - #52
Best case scenario regen converts 80%, and the remaining 20-40% is a signifiant amount of heat. I have overheated the roadsters motor on multiple occasions and regen is a signifiant contributor to that. So if there was a way to turn it off at the track I would.
I've also had a power limit because of a hot motor. It is the weak point for performance driving in the Roadster.
The Model S motor is, of course, liquid cooled.
Motor in the S is water cooled, while brakes are air cooled. I think it would really need to be something that is tested and determinded on the track. When racing, it was amazing how many things were changed to adjust for the characteristics of a specific track. Everything from tires, wheel camber, cam timing etc... I wouldn't be surprised if it was race/track/driver specific thing.
Wow, you guys are way of topic and I'm not even sure what to do with this thread.
Anyhow, to answer the question about how to control the Roadster's regen on the track, the answer is to drive two footed. You modulate your right foot to cancel out regen while you brake with your left foot. It's been done.
Anyhow, to answer the question about how to control the Roadster's regen on the track, the answer is to drive two footed. You modulate your right foot to cancel out regen while you brake with your left foot. It's been done.
BriansTesla
Old school meets new tech
From my experience hypermiling, I would like the Model S to coast without regen but to maximize regen when the brakes are applied. This should give the best efficiency. I'm sure the cruise control should do this well on the S.
You misunderstand. No regen on the brake pedal. The regen is on the accelerator pedal. Full lift off = maximum regeneration.
Instead of building the regen into the break pedal, they built it into letting off the gas pedal. It's still the same regen, just in a different place.
I haven't driven a roadster, but from what I've read it doesn't take very long to get used to the regen being activated when letting off the gas, and most people end up preferring it on the gas pedal rather than the break pedal for a number of reasons.
Yep: You only step on the brake pedal when you have to slow down quicker than the maximum regen will give you, or below the creep speed. I've seen as much as 30 kW of regen, though the gauge goes to 40.
I hear you. What I think will happen is that you'll have to educate your foot to find the no-regen spot similar to how it's done on the Prius. Also it appears that regen is much more efficient on the Tesla. Well, we'll see.
AndyM
Member
I have driven a Roadster, and loved it. I test drove a Leaf and missed it. I was very pleased when my Tesla salesperson told me (after driving it) that the Model S behaves like a Roadster in this way.
BriansTesla
Old school meets new tech
I think the S should be able to put a lot more than 30KW regen when in a medium stop. This is very easy to program in, saves brake wear and puts the maximum into the batteries. My best consumption (about 210 kw/mi) is by coasting whenever possible, braking as little as possible and letting the regen do as much of the braking as possible. Regen is free energy and I believe the best efficiency comes when the brake pads never touch the rotors.
That's what I do in the Roadster. You let off of the accelerator and regen kicks in as was mentioned above. You don't recapture all the energy with regen. I think the Roadster has max efficiency going around a constant 25 mph.
SByer
'08 #383
Tesla made the right choice - regen on the go pedal - for a couple of reasons:
- it sure makes driving in traffic a heckuvalot better.
- you can very quickly learn the distance required for near-100% regen stops.
The Honda Fit EV (*) has a cute trick - proper regen on the go pedal only means switching from 'D' to 'B' on the 'gear' selector. Several people I did the ride along with clearly preferred 'B' once they switched, in an a-ha moment thing.
Oh, and your analog brain is far better at doing a low latency blended program than anything currently in cars like the Leaf, because you have the immediate feedback even when things like pad wear are near the limits.
(*) Yes, I will keep plugging the Fit EV. It's the best thing to come out of Honda's FCV program (because they had to develop all the EV systems anyway, since an FCV is a gimped EV), probably ever, unless they do a full-EV NSX.
- it sure makes driving in traffic a heckuvalot better.
- you can very quickly learn the distance required for near-100% regen stops.
The Honda Fit EV (*) has a cute trick - proper regen on the go pedal only means switching from 'D' to 'B' on the 'gear' selector. Several people I did the ride along with clearly preferred 'B' once they switched, in an a-ha moment thing.
Oh, and your analog brain is far better at doing a low latency blended program than anything currently in cars like the Leaf, because you have the immediate feedback even when things like pad wear are near the limits.
(*) Yes, I will keep plugging the Fit EV. It's the best thing to come out of Honda's FCV program (because they had to develop all the EV systems anyway, since an FCV is a gimped EV), probably ever, unless they do a full-EV NSX.
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