Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • We just completed a significant update, but we still have some fixes and adjustments to make, so please bear with us for the time being. Cheers!

P85D vs 730HP Ferrari F12

rtz

Member
Nov 26, 2013
142
4
United States
That Ferrari reeled it in, ran it down, and walked it like it was sitting still. Takes a lot of power to do that. Still bogged off the line like a 12 second Supra though.

The Tesla needs a secret weapon. Some sort of "nitrous/boost" like button that dumps full and direct power to the motors.

The Tesla did jump off the line nicely though.

Now if the Tesla weighed half as much? How much does the battery weigh? Not all that much. Start from there and build a car on that. Doesn't and shouldn't weigh as much as it does. It's built out of aluminum! Reminds me of the fiberglass Vette that only up until recently weighed far, far too much. If you strip the fiberglass off a Corvette; there is an aluminum Corvette underneath it!

corvette_c6_z06_rolling_chassis_with_body_frame.jpg


How much does a non fiberglass Corvette weigh? I bet if it was skinned in aluminum it would weigh less than the fiberglass model.

It will be nice when Tesla decides to build a new Roadster. Hopefully they will take it to the limit; or at least offer up 2 or 3 versions of it. The base, the middle power, and the extreme. And it better be the fastest car in the world. They can get some timing lights installed on their test track and make it so.

PortaTree: Drag Race Timing Equipment, Drag Racing Equipment, Drag Racer Timing, Drag Race Reaction Time, Portable Timing Tree, Weather Station
 

dsm363

Roadster + Sig Model S
May 17, 2009
18,278
151
Nevada
I believe the battery is about 1,600 lbs. Still impressive what the P85D can do for the money given it costs $200,000 less but the Ferrari certainly is quick.
 

scaesare

Well-Known Member
Mar 14, 2013
8,200
12,995
NoVA
The Tesla needs a secret weapon. Some sort of "nitrous/boost" like button that dumps full and direct power to the motors.

What I don't think many people realize is that AC induction motors start to induce "back EMF" as RPM's rose, and thus lose efficiency. It's not that Telsa is artificially limiting power at the top end, it's that there are challenges as the motor reaches those speeds...
 

EarlyAdopter

Active Member
Jun 24, 2012
2,818
2,047
Redmond, WA
How about a transmission of some sort to keep it out of the back EMF?

Yes. As I always like to say when I see these videos: "That Ferrari is lucky the Tesla doesn't have a second gear."

Now, if only someone could make a transmission that doesn't disintegrate under instantaneous peak torque. Tesla tried on the Roadster with several companies, Borg Warner included, but no one could pull it off. Materials science isn't quite there yet.

Likewise, if Tesla wanted to (and wasn't production constrained and actually could), they could make a 2 door, 2 seat version on the Model S platform. With the weight savings they could probably shave off a half second in the quarter mile and improve handling in the corners as well.

Thing is, they don't need to build that car as they sell every Model S, and soon Model X, they can make. A few years down the road maybe.
 

Todd Burch

Voltage makes me tingle.
Nov 3, 2009
7,801
28,498
Smithfield, VA
I don't think back-EMF is the limiting factor with the P85D. I think it's the power output of the battery. The 85kWh pack can put out some serious power, but not for more than a few seconds. At that point it has to back off to protect the battery.

I don't have any technical info to back that up, but that's my hunch.
 

kennybobby

Member
Sep 14, 2014
478
36
Heart o' Dixie
And the Tesla has no wheel spin off the line. To think that a 4 door sedan jumps a Ferrari till about half way down the track up to legal highway speeds makes the ICE racers a little sick to their stomach...

As an electric motor speed increases, the back-emf voltage (which is of opposite polarity) approaches the battery pack voltage level and opposes the current flow since there is less potential difference to force the current. Torque can be thought as proportional to current, so as the current gets reduced, so does the torque, which is the force that produces acceleration. 0-60, stoplight to stoplight, the electric motor wins on the street.
 

scaesare

Well-Known Member
Mar 14, 2013
8,200
12,995
NoVA
I don't think back-EMF is the limiting factor with the P85D. I think it's the power output of the battery. The 85kWh pack can put out some serious power, but not for more than a few seconds. At that point it has to back off to protect the battery.

I don't have any technical info to back that up, but that's my hunch.

Yet, you can be cruising at 70 for 30 minutes only pulling ~20KW, so the battery will be relatively cool having been averaging only 1/4C... and if you floor it at those speeds you don't get nearly the torque you get at low RPM despite the battery being in a state where it can deliver max power for several seconds.

The motor simply can't develop the same torque it can at elevated speeds as it can at 0 RPM. This is illustrated by the power curves published for AC induction motors...
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top