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The Quarter Mile
- Thread starter tonybelding
- Start date
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- Performance Roadster
If you set up a sport model strictly for drag racing, you might get it into the 11's, but barely.
You would need a better cooled PEM and bigger water cooled motor to go faster that that.
Another option is to loose battery weight while keeping the same discharge rate. There are other battery options, but are very expensive.
You would need a better cooled PEM and bigger water cooled motor to go faster that that.
Another option is to loose battery weight while keeping the same discharge rate. There are other battery options, but are very expensive.
The Roadster Sport shines in 0-80, but then starts to fall off in vigor.
If someone were determined to improve 1/4 mile time I would think the area to improve would be high RPM output of the motor.
And as QWK basically said there are cooling concerns and perhaps max battery power output limits that would need to be addressed.
Another option would be to reduce weight.
If you were willing to sacrifice range for performance, a 200lb battery pack, with 10kWh and an ultracap front end could probably work wonders in the 1/4 mile.
I think the gearing is already well suited to 1/4 mile runs. Also we don't seem to have much of a traction issue.
If someone were determined to improve 1/4 mile time I would think the area to improve would be high RPM output of the motor.
And as QWK basically said there are cooling concerns and perhaps max battery power output limits that would need to be addressed.
Another option would be to reduce weight.
If you were willing to sacrifice range for performance, a 200lb battery pack, with 10kWh and an ultracap front end could probably work wonders in the 1/4 mile.
I think the gearing is already well suited to 1/4 mile runs. Also we don't seem to have much of a traction issue.
Anyone calculated how much energy the Roadster takes to do a 1/4 mile? I would imagine it is rather consistent.
For a 1/4 mile is would be a bit over 1kWh.
Anyways, if one were to do an ultra-capacitor front end for a quarter mile optimized racer they would probably want enough ultra-caps to hold enough charge for the full 1/4 mile. Then the regen and aux lithium pack could recharge the ultra-caps as you slow back down and creep you way back around to the starting line again.
For a 1/4 mile is would be a bit over 1kWh.
Anyways, if one were to do an ultra-capacitor front end for a quarter mile optimized racer they would probably want enough ultra-caps to hold enough charge for the full 1/4 mile. Then the regen and aux lithium pack could recharge the ultra-caps as you slow back down and creep you way back around to the starting line again.
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You've got your math backwards; divide the energy by the distance not the other way around. 53kWh/244 miles = ~217 Wh/mile. However, your assumption that drag racing is only twice as expensive as ideal range is also way off. In another thread Tom Saxton reported that the 1/4 mile runs at the Wayland Invitational used about 5 ideal miles, or about 1.1 kwH.
My 2010 Roadster is anemic off the line. One-wheel drive and skinny tires -- still can't even spin the tire(s). It launches so weak that all my passengers think I'm lying when I tell them that it's a 13-second car. TC button seems to makes no difference on dry pavement when launching. I think the car's software is limiting the power off-the-line in order to prevent things from breaking. Lame. I've heard a few people say that AC motors don't have the full torque at 0 RPM like the DC motors do, but I'm not a hardware guy so I don't know if that's true or not. This car seriously needs 2 gears (or 2 motors) if it's ever going to be competitive in the 1/4 mile. As it sits, it only feels fast from 10mph - 70mph. To get from 0mph to 10mph takes an eternity. It's not just my car either, I've driven several Teslas and they all feel that way.
p.s. I'm aware that a few Teslas have snuck into the 12s on a few occasions, but in a typical street race scenario when you're caught off guard with a 50% battery charge and not in performance mode you're really looking at high 13s.
p.s. I'm aware that a few Teslas have snuck into the 12s on a few occasions, but in a typical street race scenario when you're caught off guard with a 50% battery charge and not in performance mode you're really looking at high 13s.
I have an electric blue 2010 Tesla Roadster - one of the first 100 of the 2.0 cars.
I don't know how to make it spin the tires off the line on dry pavement.
It definitely seems most spectacular from 15-60 after the first fraction of a second.
On 7/24/2010 at the Wayland Invitational I did 4 quarter mile runs, total driving distance was 4.5 miles.
My SOC started at 80% and ended up at about 73% when I was done ( about 17 ideal range mode miles )
The car was driven to the track a few hours earlier in standard mode, and sat there a couple hours not plugged in until I turned it on, put it into performance mode and went to the staging lanes. ( The battery started "cold" and at the end of the 4 runs had only warmed one bubble on the temp gauge )
Traction control was off.
I weigh 185 pounds and I had a trunk full of crap I could/should have removed ( pretty sure my mobile charger was in there ).
I was "one footing" it, I had my foot on the brake and jumped off onto the go pedal when the light changed.
My opponent was two footing it, left foot on the brake, right foot on the go pedal, jump off the brake when the light changed.
My times from the track timer ( other lane was a 2008 Tesla roadster, I'm not sure of his SOC ):
13.004 @ 103.14 mph ( vs 13.384 @ 103.35 mph - Forgot to turn off TC? )
13.003 @ 103.06 mph ( vs 12.978 @ 103.40 mph )
12.968 @ 103.27 mph ( vs 13.007 @ 103.40 mph )
12.987 @ 101.13 mph ( vs 13.028 @ 104.32 mph )
It seems weird to have a quicker time at lower mph.
I hope to experiment more with the variables:
1) SOC
2) battery temp
3) tire pressure
p.s.: If I get the feeling that I might want it, I can and do switch in to performance mode on the street in a fraction of a second.
I don't know how to make it spin the tires off the line on dry pavement.
It definitely seems most spectacular from 15-60 after the first fraction of a second.
On 7/24/2010 at the Wayland Invitational I did 4 quarter mile runs, total driving distance was 4.5 miles.
My SOC started at 80% and ended up at about 73% when I was done ( about 17 ideal range mode miles )
The car was driven to the track a few hours earlier in standard mode, and sat there a couple hours not plugged in until I turned it on, put it into performance mode and went to the staging lanes. ( The battery started "cold" and at the end of the 4 runs had only warmed one bubble on the temp gauge )
Traction control was off.
I weigh 185 pounds and I had a trunk full of crap I could/should have removed ( pretty sure my mobile charger was in there ).
I was "one footing" it, I had my foot on the brake and jumped off onto the go pedal when the light changed.
My opponent was two footing it, left foot on the brake, right foot on the go pedal, jump off the brake when the light changed.
My times from the track timer ( other lane was a 2008 Tesla roadster, I'm not sure of his SOC ):
13.004 @ 103.14 mph ( vs 13.384 @ 103.35 mph - Forgot to turn off TC? )
13.003 @ 103.06 mph ( vs 12.978 @ 103.40 mph )
12.968 @ 103.27 mph ( vs 13.007 @ 103.40 mph )
12.987 @ 101.13 mph ( vs 13.028 @ 104.32 mph )
It seems weird to have a quicker time at lower mph.
I hope to experiment more with the variables:
1) SOC
2) battery temp
3) tire pressure
p.s.: If I get the feeling that I might want it, I can and do switch in to performance mode on the street in a fraction of a second.
stopcrazypp
Well-Known Member
I think Tesla chose an open diff for efficiency reasons if I remember correctly, although that could help the car during launch.
A "launch control" mode probably would help too. Pretty much all the new high end sports/super cars have one.
A "launch control" mode probably would help too. Pretty much all the new high end sports/super cars have one.
DrTaras
R254->R725->S->X->M3->M3P-->R2020?
Does "Perfomance Mode" allow you quicker 0-60 Times?
Which brings up a point that VFX & DrComputer & I were debating.
Does "Perfomance Mode" allow you quicker 0-60 or Quarter Mile times?
PS-I see a similar question posed in the "0-60 in 3.9s" thread from today.
Which brings up a point that VFX & DrComputer & I were debating.
Does "Perfomance Mode" allow you quicker 0-60 or Quarter Mile times?
PS-I see a similar question posed in the "0-60 in 3.9s" thread from today.
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tomsax
Member
I did a 12.978 sec 1/4 mile ET at 103.40 mph at the Wayland Invitational V on July 24th in our 2008 Roadster. I used 700 Wh for that run, and gained back 140 Wh from regen (it would be more, but I have to apply friction brakes to make the turnout). Other runs that day used between 640 and 715 Wh.
RichKae turned in a 12.968 ET at 103.27 in his 2009 Roadster, using 743 Wh.
If someone has done a quarter mile in a Roaster Sport recently, send me a message and I'll help you do the energy calculation.
BTW, last Friday, DaveD and I watched John Wayland's White Zombie set a street-legal EV 1/4 mile world record at Portland International Raceways: 10.400 sec 1/4 mile ET at 117.21 mph, best 1/8 mile time was 6.533 sec ET at 106.33 mph. The 0-60 time is estimated to be somewhere around 1.9 seconds. I posted more info in the Wayland Invitational V thread.
RichKae turned in a 12.968 ET at 103.27 in his 2009 Roadster, using 743 Wh.
If someone has done a quarter mile in a Roaster Sport recently, send me a message and I'll help you do the energy calculation.
BTW, last Friday, DaveD and I watched John Wayland's White Zombie set a street-legal EV 1/4 mile world record at Portland International Raceways: 10.400 sec 1/4 mile ET at 117.21 mph, best 1/8 mile time was 6.533 sec ET at 106.33 mph. The 0-60 time is estimated to be somewhere around 1.9 seconds. I posted more info in the Wayland Invitational V thread.
So ~700wh for the full pedal 1/4 mile would equate to 2800wh/mi. (four quarter miles).
Compare to approx 280wh/mi crusing freeway speeds, and full acceleration 1/4 mile seems like ~10x the energy usage of steady state cruising.
Another thing to consider, a full pack (53kWh) is good for about 75 1/4 mile runs (53000/700).
Just pondering the numbers.
Compare to approx 280wh/mi crusing freeway speeds, and full acceleration 1/4 mile seems like ~10x the energy usage of steady state cruising.
Another thing to consider, a full pack (53kWh) is good for about 75 1/4 mile runs (53000/700).
Just pondering the numbers.
tomsax
Member
One more bit of data...
On July 30, after driving to Portland, I charged up for about 90 minutes to 36% in performance mode. I ran my worst ever 1/4 mile: 13.732 sec ET at 99.31 mph. That was my usual launch: performance mode, TC off, two-foot start.
In a lower state of charge, both the pack voltage and maximum current are lower, yielding less performance. I definitely won't be doing any more runs with the SOC lower than 80% or so.
I keep thinking I should try a standard mode run, maybe single foot, compared back-to-back with a like performance mode, but it's hard to do when you're at the track with a bunch of spectators watching your time.
On July 30, after driving to Portland, I charged up for about 90 minutes to 36% in performance mode. I ran my worst ever 1/4 mile: 13.732 sec ET at 99.31 mph. That was my usual launch: performance mode, TC off, two-foot start.
In a lower state of charge, both the pack voltage and maximum current are lower, yielding less performance. I definitely won't be doing any more runs with the SOC lower than 80% or so.
I keep thinking I should try a standard mode run, maybe single foot, compared back-to-back with a like performance mode, but it's hard to do when you're at the track with a bunch of spectators watching your time.
Adm
Active Member
"Tesla Roadster The Roadster sprinted the quarter mile in 11.46 seconds at the 2010 Speed Trials of the Brighton & Hove Motor Club -- the longest running motorsport event in the world. Then UK sales manager Gian Avignone sprinted home to London, with half a charge to spare. (He stopped once for this courtesy photo shoot.)"
Found this on the Facebook page of the Tesla Roadster... Was he going down hill or is the Portland track up hill? I assume a 1/4 mile is the same in the UK and the US.
Found this on the Facebook page of the Tesla Roadster... Was he going down hill or is the Portland track up hill? I assume a 1/4 mile is the same in the UK and the US.
tomsax
Member
Can you give us the link to where this quote is? A number without an impartial witness and a timeslip is just a rumor.
11.46 seconds is really hard to believe. The 2010 Sport Model was getting times in the mid 12's. Dropping to 11.46 is a seriously huge difference. If the 2.5 Roadster Sport was that much faster, the 0-60 time would have to be a lot lower than 3.7 seconds, and I would think we'd be hearing about it from Tesla on the front page of their web site.
tomsax
Member
John Wayland's White Zombie set a new record for a street legal EV at the NEDRA Nationals this past weekend: 10.258 1/4 mile ET at 123.79 mph.
shark2k
Member
It's on the Facebook page. They don't have a link to anything, just pictures and the description.
-Shark2k
Tdave
Member
The Facebook page: Tesla Roadster
And I think this goes directly to the posting: Brighton & Hove Motor Club
And there's this comment to that post by the Official Page of Tesla Motors: "Tesla Roadster @Satyaraj: This is the stock Tesla Roadster Sport 2.5. It's not modified."
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