Track day this weekend...charge mode and driving mode question?

[Doug_G]

Personally I would be concerned about keeping the battery warm. Lapping will take care of that. Try to keep it cool instead. "Cool" means room temperature, which is fine for pulling power from the battery. Range mode will try to get it to room temperature.

For 110, just plug it in. Won't really help, but won't hurt.

If the RV park is just 8 miles away, I'd suggest going back there for lunch and a top up.

In my experience, you really need to be charging at least 240V/40A between each session if you want to run all day.

 

[richkae]

Just to be clear, when I said: "Charge in range or standard as soon as possible when you are done driving on the track to cool the battery back down." that means when you are done for the day and not going back out onto the track.

 

[djp]

I found a RV park that is 8 miles away from the track where I will be charging the Roadster overnight. The temps in Dallas are about low 45 high 65 predicted.
At night since the car is outside, would you charge it at performance to keep the battery warm? and assume I have only access to a 110...would you just charge standard?

Perfect. I'd book the RV park for the day so you can charge and cool down there over lunch, and recharge at the end of the day.

I'd charge in Range overnight to give you a starting point around 70F for the battery. This should give you three or four sets before it reaches 105F. If you charge in Performance your starting temperature will be higher giving you less laps before you hit 105F.

Over lunch charge either in Standard or Range Mode. The more charge you can add the better, and you'll probably be able to get the battery temp down to 80F after an hour, giving you another one or two sets in the afternoon.

If you only have 110V and no access to 240V, plan on doing a half day only. You can plug into the 110V if it makes you feel better, but it won't do much.

 

[7racer]

thanks everyone! I'll let you know how it goes.

 

[wiztecy]

thanks everyone! I'll let you know how it goes.

Cool, have fun and kick some watts out! Was a great discussion and thread, thanks to everyone for that

Curious... has anyone changed out their steering rack for a 2.5 or 2.2 to lock rack? Stock is 2.75 to lock. Looks like this is a nice and easy improvement on quicker steering response. Wondering if 2.2 would be too twitchy for the street. Stock is not responding as much as I'd like it too, it responds but it for sure can be better especially when you have a tighter suspension.

 

[7racer]

Cool, have fun and kick some watts out! Was a great discussion and thread, thanks to everyone for that

Curious... has anyone changed out their steering rack for a 2.5 or 2.2 to lock rack? Stock is 2.75 to lock. Looks like this is a nice and easy improvement on quicker steering response. Wondering if 2.2 would be too twitchy for the street. Stock is not responding as much as I'd like it too, it responds but it for sure can be better especially when you have a tighter suspension.

I was interested in getting that same rack from sector111. If I see any lotus's at the track I'll ask if they have heard any feedback.

- - - Updated - - -

run 3.27 miles, at 54 degrees, with drizzling rain, along a 4 lane highway, at 9pm on a Friday night....
just so I can charge an electric car at a RV park and sleep at a hotel!....
only to turn around to drive the cars in circles all weekend!!!!

#firstworldproblems

 

[wiztecy]

I just got done playing around with 30-40mph rear slides on some quick twisties by the oceanside, that steering response is a definite weak link in the mix when the body's tight. You can just feel you're spinning the steering wheel just a little too much (in an awkward way) when that back end whips back and you really don't want to exaggerated your input which is the key to the whole car recovering from the turn. The more you get connected to your tires the more you'll feel through the steering wheel and you want to put input back into the "system" as quick as you can, hence where the beautify of the tighter rack comes in. I think I'm going to go for the new rack, the old just feels too sloppy now. Now its a 2.2 vs. 2.5. The 2.5's on-sale so that looks very appealing The 2.2 is almost double the price.

I also think adding poly bushings on the control arms will add more feel to the wheels. But will also add more vibrations/road noise so there's going to be a tradeoff for those who want a plush ride.

Love the Running pic 7racer!! Fitness is key to racing so keep that in mind And once the helmet is on, the accelerator is to the floor, and your entering your first turn you'll be always happy you did it! One thing is that Racing an electric car does have is unique character to it both night and day!

However the only thing that worries me is your heart rate beats per minute is 0!

 

[7racer]

Haha! Wasn't wearing the heart rate monitor. It is different driving the tesla on the track. It definitely does better at an auto cross vs track but was able to pass about 5 cars and keep pace with a Hyundai genesis for a while.

There are RV plugs at the track (MSR) but they are the 3 prong ones. Which one is that?!? I don't know my adapters well.

Like others have mentioned. You get power limited. I ran the first 20 min session to about 18 mins before power was cut. Only got 15 this last on. Two more to go. What I didn't know was when it goes into power limited mode I thought it would cut back torque but it cuts top speed. At one point I could only get to 70mph. Then 50.

The morning was colder with it being around 48 degrees. It's warming up quick and will see what the afternoon holds.

I charged in range mode and drove in performance the first session, standard the second. Couldn't see any difference and it didn't seem to prevent power from being limited.

Also, it looks like it's the motor that takes the hit first. Battery and PIM seems fine (pic after second session)

 

[7racer]

Also on the track I had my arms cross more than when I drive my GTR. What I mean is like having your hands at 3-9 and you turn. My hands almost got full 9-3 crossed, so maybe a quicker steering rack isn't such a bad idea.

Finally, they need to move the freaking horns!! I honked at more people on the track inadvertently than using it on public roads!!

 

[wiztecy]

There are RV plugs at the track (MSR) but they are the 3 prong ones. Which one is that?!? I don't know my adapters well.

Fun!!! Thanks for the update and the pics Any Lotus Elises there? That quicker rack should help keep your hands from being too busy going through the turns, start to realize how small that steering wheel really is in the moment!
Here's some previous forum talk on the RV outlet I believe you're talking about:
Charging at Campgrounds and RV Parks

"The campground 30 amp connections are apparently 120V not 240V. So using a TT-30 adapter one would have to use the MC120@12 or 16amps, not the MC240 at 24amps+."

Does the outlet look like the one below?

 

[7racer]

Here's some previous forum talk on the RV outlet I believe you're talking about:
Charging at Campgrounds and RV Parks

"The campground 30 amp connections are apparently 120V not 240V. So using a TT-30 adapter one would have to use the MC120@12 or 16amps, not the MC240 at 24amps+."

Does the outlet look like the one below?

View attachment 33438

Yes!! So getting that adapter. Pulsing help me charge any quicker would it?

 

[wiztecy]

Yes!! So getting that adapter. Pulsing help me charge any quicker would it?

Have to read further through the thread to verify someone has successfully charged with the MC120 off the TT-30 outlet. I'm not sure if the MC-120 is a dumb circuit or if its the Roadster that senses the current, since there'll be 30 amps on the line.

 

[7racer]

Have to read further through the thread to verify someone has successfully charged with the MC120 off the TT-30 outlet. I'm not sure if the MC-120 is a dumb circuit or if its the Roadster that senses the current, since there'll be 30 amps on the line.

Yea I'm on my iPhone trying to read that thread too. Sorry about the autocorrect on the last post!

 

[wiztecy]

Ok... I'm breezing thought the posts and trying to find confirmation of someone charging that way. If so I'll post the link to the thread, easier on my end reading these posts than you.

 

[wiztecy]

So this is what I found, the MC120 is designed for low current. It appears you can drive the MC120 to pull 12Amps or override it to a max of 16Amps at the VDS. Some said it can pull a max of 24 Amps, but I think that's at the outlet and only possibly if you make a custom adapter then run the MC240 off it. I've only charged with the mc120 off 10Amps so I can't give any personal feedback here.

Appears there are adapters you can make to utilize your MC240/UMC to utilize the full 30 Amps (really 24 usable amps) of the TT-30. By the way the TT stands for Travel Trailer, or Time Traveler as doug mentioned in one thread

I believe it should work with the adapter, especially if you dial down the Amps at the VDS. If there's too much current pulled across the mc120 wouldn't the GFCI trip on it? And if the Roadster limits the current to what the mc120 can handle then the mc120 GFCI and wires should be fine right? I don't believe there's a pilot signal on the mc120, that's with the mc240. However I don't know if the VDS will stay no thank you and prevent charging to ever begin.


Now richkae came up with making an adapter that will work on your MC240 which allows the pilot signal to be happy and where you can pull the full 24Amps from the 110V circuit. Here are the links I came across that discuss this topic:

Charging at Campgrounds and RV Parks - Page 9

Charging at Campgrounds and RV Parks - Page 12

Did anyone try to charge MS using TT-30 ? - Page 2

 

[djp]

Yes!! So getting that adapter. Pulsing help me charge any quicker would it?

Sounds like a fun morning despite hitting the motor temp limit so quickly. That adapter is 120V so it won't do you much good, even if you could trick the Roadster into accepting more than 15A. I think heading back to the RV park over lunch is still your best bet. Have fun!

 

[7racer]

Made it 15 mins before motor heat limited power. Had a good flow going. It really is a pretty fun track car once you get it going. I was driving it like the GTR trying to put the power down instead of just using the momentum and torque.

I have one more session to go but with only 52 miles showing. Not sure if I will be able to get it all in.

 

[7racer]

Addendum. Ambient temp now 71 degrees but PEM and battery temps fine. Just the motor temps that I keep running into.

 

[Doug_G]

Sounds about right. I think you'd only run into battery limits in very high ambient temperatures. I've never had it happen. It's always been the motor.

 

[7racer]

just some late night thoughts after the first full track day.

1. I thought that the car had too much understeer and I was ready to have the performance shop stiffen the rear sway, but in the stock setting, the car is surprisingly neutral. There is a bit of understeer, but not that bad and you can mostly throttle out of it.
2. On my fastest session, after hitting the paddock, I barely heat the fronts up. That is the pressure doesn't go up that much in the tires. Maybe I could work them harder or the compound might be too hard for the track. I am running the "comfort" pressure settings, I think 25 front 35 rear. I might try a couple pounds lower in the front tomorrow.
3. While the front tires have that typical "scrubbed" look after a track event, the rears look barely used...maybe I need a bit more oversteer?
4. looking at track times on the web, the Roadster seems to be close to a E46 M3 on the track, at least at MSR on the 1.7*