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      08-02-2013, 02:18 AM   #45
Lucrecio84
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i would get one as my daily driver to commute but would need to have something with some balls sitting in the garage
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      08-02-2013, 09:54 PM   #46
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i would get one as my daily driver to commute but would need to have something with some balls sitting in the garage
Quick, silent and precise as a stealth ninja?
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      08-03-2013, 08:18 PM   #47
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Quote:
Originally Posted by Killerfish2012
Wonder how good the teslas are at HPDE?
Ive seen a couple teslas at hpde. One went to go charge at an autox. I thought he left and only did one run.

At the roval, it was pushing a lot. It has to be pretty heavy but im sure a better driver would have faired much better. It is damn fast in the straights though. An instructor was on my ass with the model s on the first lap (used to warm up) then i said hell with it and went all out on that lap. He was pretty far behind - i guess it was the turns and braking.

And i am by no means a great driver.
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      08-03-2013, 09:31 PM   #48
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My performance S is faster off the line than my e90 m3 ess vt2-625. Torque is instant and constant 440ft lbs from 0-50.
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      08-04-2013, 12:10 AM   #49
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Quote:
Originally Posted by 4sevens.com
My performance S is faster off the line than my e90 m3 ess vt2-625. Torque is instant and constant 440ft lbs from 0-50.
What happens after 50? Is tq based on mph? Interesting.
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      08-04-2013, 12:38 AM   #50
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Quote:
Originally Posted by pkim1079 View Post
What happens after 50? Is tq based on mph? Interesting.
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Originally Posted by 4sevens.com View Post
My performance S is faster off the line than my e90 m3 ess vt2-625. Torque is instant and constant 440ft lbs from 0-50.
Constant ?? I don't know the specifics about Tesla S but here is what any DC motor torque will look like :



Torque start at max and then drops linearly as RPM increases. Where as for gas engines there is a relatively flat or increasing midband and the 0rpm torque is zero.

Here is the power curve of a DC motor (red curve). I builds up and reaches a max and then drops. Also shown is the efficiency curve. It shows the electric car is very inefficient if driven hard but very efficient when cruising (hence the hybrid car relaying the gas engine at higher rpms)



So the car is like a coiled spring with big initial pull and as it build speed it looses torque. Not very desirable (vaguely similar in feeling to an automatic box planetary torque converter that will boost initial torque but looses torque immediately when car starts taking speed). It may look impressive at a stop light because we assume that such torque stays as it would for a gas engine but instead it vanishes. Gearing for such a motor would have to be very short (a lot of gears, or continuously variable gearing) if the car is destined for sports.
Tesla may use some switched supply DCDC converter to make that torque curve hold a bit more initially but it will never change this characteristic entirely.

Last edited by sunsweet; 08-04-2013 at 01:05 AM.
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      08-04-2013, 03:17 AM   #51
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I totally forgot to mention how much it drops after said 50mph. I was curious as to how much torque it would be able to hold passed said 50mph.
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      08-04-2013, 10:57 AM   #52
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Quote:
Originally Posted by pkim1079 View Post
I totally forgot to mention how much it drops after said 50mph. I was curious as to how much torque it would be able to hold passed said 50mph.
You could have found the answer from my post.
50 mph = 80 km/h = 22 m/s
torque has dropped by 40% at 22 m/s. It's not the Tesla engine but gives a ballpark number. In comparison the S65 engine reaches its max torque and holds it all the way to 7,000 rpm. No DC motor for me, thanks.
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      08-04-2013, 11:40 AM   #53
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I was at Laguna Seca when they had the Refuel run groups last month. I was talking to a guy who had a Tesla Roadster. He said that the problem for him wasn't that the batteries ran out of juice. He said the issue was that when you demand performance driving from the batteries, the batteries get reallllllly hot, and that's the reason the power drops.

And to be fair, most of the Refuel event cars were pretty much unmodded from a performance tracking standpoint. So, if their times weren't overly impressive, I would actually blame that on things other than the propulsion system.

Anyway, on a hot day, my M3 only gets a couple solid hot laps before it pulls power and starts complaining about the engine being too hot. Now, on a cool day---70 degrees or less, my car is in good shape all day long.

You know what impresses me? Member Ti-Jean on this forum has both an E90 M3 and a Porsche GT3. His M3 overheats like crazy when it's warm. But his GT3------geez-----it doesn't matter how hot it is, the temperature needle on his car NEVER MOVES. You know what cracks me up? It takes him awhile to strap himself into the GT3 because of the full harness, Hans device, etc. On a super hot day, he actually runs the A/C while he's strapping in, and keeps running it until the session starts. Then once he's about to go on track, he turns it off and then he can run a full 30 minute session in the heat no problem.
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      08-04-2013, 12:00 PM   #54
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Quote:
Originally Posted by dogbone View Post
You know what impresses me? Member Ti-Jean on this forum has both an E90 M3 and a Porsche GT3. His M3 overheats like crazy when it's warm. But his GT3------geez-----it doesn't matter how hot it is, the temperature needle on his car NEVER MOVES. You know what cracks me up? It takes him awhile to strap himself into the GT3 because of the full harness, Hans device, etc. On a super hot day, he actually runs the A/C while he's strapping in, and keeps running it until the session starts. Then once he's about to go on track, he turns it off and then he can run a full 30 minute session in the heat no problem.
for the GT3
I would be interested to know if there are ways to mod to M3 to keep it running cooler on the track. Or is it something you have to live just better engine design in the GT3 ?

BTW the curves I showed explain why the Tesla battery would run hot if driven hard. Efficiency is worst at max torque. The electrical battery sees virtually no load (short circuit) at max torque. Take a 9V battery and short it with a copper wire (do not attempt). It will heat up and even may burst. It does not matter if you use super high conductivity wires or not, it happens inside the battery tank. High currents creates a lot of torque but the battery will heat real fast. That is why fixed DC motors are powered from AC/DC rectifying transformers not ions batteries.
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      08-04-2013, 12:55 PM   #55
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Quote:
Originally Posted by Team Plutonium View Post
The larger oil cooler form M24 helps a lot. I saw a difference of 25 degrees. Chris (CBS) just had it installed and will be tracking with it all season; I'm sure he can chime-in as well. It's on the pricy side, but well worth it if you track a lot. I believe Keith (Klammer) is running one as well.

http://ind-distribution.com/blog/?p=806
thanks a lot, I will definitively look into it.
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      08-04-2013, 01:13 PM   #56
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I should mention that Ti-Jean's car has aftermarket cooling and it's not doing much for him.

I'll let him know about this thread and see if he can comment.
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      08-04-2013, 08:34 PM   #57
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Quote:
Originally Posted by sunsweet View Post
for the GT3
I would be interested to know if there are ways to mod to M3 to keep it running cooler on the track. Or is it something you have to live just better engine design in the GT3 ?
One thing that help on the GT3 (I'm no mechanic so just speaking out of common sense) is that the engine in the GT3 is exposed underneath the car. The M3 engine is trapped from both top and bottom. I suspect the heat gets stuck in the M3 and basically heat soak the engine.

Quote:
Originally Posted by Team Plutonium View Post
The larger oil cooler form M24 helps a lot. I saw a difference of 25 degrees. Chris (CBS) just had it installed and will be tracking with it all season; I'm sure he can chime-in as well. It's on the pricy side, but well worth it if you track a lot. I believe Keith (Klammer) is running one as well.

http://ind-distribution.com/blog/?p=806
Quote:
Originally Posted by dogbone View Post
I should mention that Ti-Jean's car has aftermarket cooling and it's not doing much for him.

I'll let him know about this thread and see if he can comment.

I'd love to hear their experience. I have a similar setup custom built and it did nothing for me as far as preventing overheating. Basically, I have an additional inline oil cooler (like the M24) and replaced the DCT cooler with one 2.5 times bigger. I did lots of dyno testing to see if the location of the additional oil cooler matters but it doesn't seem like it. Only difference for me is that, when I overheat, all I need to do is pull back just a bit (lets say short shift between 6k-7k RPM) and I can see the temp needle drop. In short, it helps recover from overheating very fast but doesn't prevent overheating.

What I really wanted is something that lets me redline all day without overheating. I got that with my GT3 but not the M3.
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      08-04-2013, 10:13 PM   #58
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Quote:
Originally Posted by 4sevens.com View Post
My performance S is faster off the line than my e90 m3 ess vt2-625. Torque is instant and constant 440ft lbs from 0-50.
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      08-04-2013, 10:40 PM   #59
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Quote:
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nice stable.
but how do you know that ? do you have dyno curves to proove it ?
I would be surprised if engine torque does not drop drastically above that.

I think the Tesla S is still the infancy of a new technology and cannot yet be considered seriously as a race car despite its torque at 0mph. Its $40,000 panasonic battery pack does not recover if you discharge it on a racetrack. It's the "brick" syndrome where the car cannot even be towed. Petroleum fuel is just much superior for storing energy.
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      08-04-2013, 10:49 PM   #60
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Mr sunsweet - looks like we are in the same state... Let's meet and then I'll let you explain first hand PM me
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      08-13-2013, 08:06 AM   #61
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Coming out with a AWD vehicle next year. This should be interesting!
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      08-13-2013, 11:18 AM   #62
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Quote:
Originally Posted by Team Plutonium View Post
The larger oil cooler form M24 helps a lot. I saw a difference of 25 degrees. Chris (CBS) just had it installed and will be tracking with it all season; I'm sure he can chime-in as well. It's on the pricy side, but well worth it if you track a lot. I believe Keith (Klammer) is running one as well.

http://ind-distribution.com/blog/?p=806
That looks great. I think there should be a lower cost solution though. The M24 cooler is quite pricey.

While we're on the subject of cooling... is there any way to keep the power steering fluid from boiling over?
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      08-13-2013, 11:53 AM   #63
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Originally Posted by dogbone View Post
I was at Laguna Seca when they had the Refuel run groups last month. I was talking to a guy who had a Tesla Roadster. He said that the problem for him wasn't that the batteries ran out of juice. He said the issue was that when you demand performance driving from the batteries, the batteries get reallllllly hot, and that's the reason the power drops.

And to be fair, most of the Refuel event cars were pretty much unmodded from a performance tracking standpoint. So, if their times weren't overly impressive, I would actually blame that on things other than the propulsion system.

Anyway, on a hot day, my M3 only gets a couple solid hot laps before it pulls power and starts complaining about the engine being too hot. Now, on a cool day---70 degrees or less, my car is in good shape all day long.

You know what impresses me? Member Ti-Jean on this forum has both an E90 M3 and a Porsche GT3. His M3 overheats like crazy when it's warm. But his GT3------geez-----it doesn't matter how hot it is, the temperature needle on his car NEVER MOVES. You know what cracks me up? It takes him awhile to strap himself into the GT3 because of the full harness, Hans device, etc. On a super hot day, he actually runs the A/C while he's strapping in, and keeps running it until the session starts. Then once he's about to go on track, he turns it off and then he can run a full 30 minute session in the heat no problem.
I've done 25-30 minute sessions in 104 degree weather at Thunderhill (with and without a non-intercooled supercharger) and my car has never overheated. I noticed DCT cars tend to overheat more often.
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      08-13-2013, 12:18 PM   #64
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Better start praying because you own two of the nine cars people drive in hell.

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      08-21-2013, 11:44 PM   #65
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Sorry but I'm done with my M3

http://www.teslamotorsclub.com/showt...-BMW-M3-sedan-(and-everything-else-out-there)
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      08-22-2013, 02:31 AM   #66
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I'm really interested in the Model S and hope to pick one up in the future (not as an M3 replacement), but it sounds like you drank too much of the Kool-Aid.
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