How to get P85 to full power

[sorka]

That's outside of the box . I'll see if I can safely get that set up.

So service called me and told me that I'm getting 1200 amps peak that drops off to 1150 quickly and that peak voltage is "in the mid 300s". That puts peak power in spec but it doesn't really say anything about ramping to that point or sustained power. The service guy told me that to really get to the types of times i see online, or even to the spec of 4.2, I'd probably need to turn off TC and get to a sticky road / track. After warning about never turning off TC though, which I believe.

That really means nothing since peak voltage does NOT occur when peak current does. You need voltage at the time peak current occurred. I don't think they're trying to tell you that it made 400 amps @ 350 volts as that is more power than a P85D.

 

[SarahsDad]

Another data point - I acheived 364KW according to Power Tools App at 98% SOC last year in my P85+.

 

[raphy3]

Another data point - I acheived 364KW according to Power Tools App at 98% SOC last year in my P85+.

View attachment 231074

OK thanks for that data point. Going to see how cost I can get to that. IIRC the + does not have any extra power, it's more about handling, so I should be able to get in the ballpark.

That really means nothing since peak voltage does NOT occur when peak current does. You need voltage at the time peak current occurred. I don't think they're trying to tell you that it made 400 amps @ 350 volts as that is more power than a P85D

I see what you're saying. I've had a hard time getting crystal clear answers. When I grilled the service guy I asked him what my voltage was at that amperage and he said it was ~350 at 1100 amps. So that's like 470hp. Is that too high for a P85?

 

[sorka]

OK thanks for that data point. Going to see how cost I can get to that. IIRC the + does not have any extra power, it's more about handling, so I should be able to get in the ballpark.

I see what you're saying. I've had a hard time getting crystal clear answers. When I grilled the service guy I asked him what my voltage was at that amperage and he said it was ~350 at 1100 amps. So that's like 470hp. Is that too high for a P85?

A tad too high yes. But they're wrong or not giving you the correct data as you've always proven you're not getton more than 340kw.

 

[raphy3]

A tad too high yes. But they're wrong or not giving you the correct data as you've always proven you're not getton more than 340kw.

Yeah I agree. I want to get more data before I go back to them with more questions. I want to say something like "it was in spec before you sold it sure, but now it's out of spec. Could just be a coincidence that it is failing now." After all, the guy did tell me that they had the previous 3 month's worth of data on hand. Well I only had the car for two weeks by the time they called me back. So he could have been reading off peak powers from a month ago when everything was just fine, before I had it.

 

[raphy3]

Another minor update. I got the CANtact but now am waiting on my cable to use it. The plot has thickened: with the pedal to the floor at 95mph the power meter shows a dashed line at 310kw, twice yesterday. The service people told me that happens when the battery is being taxed too hard and the power output needs to be limited to protect it. However, if my battery is being taxed too hard such that the car can't go above 95mph, that seems like awfully abnormal behavior. I'll have to try to get it above 95 a few more times and see if the dashed line consistently appears. It'll be useful to have the CANtact output at that time too.

Edit to add: yup, totally consistent. I can get dashed lines on demand starting at 90mph if I try to accelerate hard at that speed. Demoed it to myself a few times. Is this normal? I was able to get over 100 and then had to slow down due to traffic.

 

[Zextraterrestrial]

I am currently driving a loaner regular 85, 2013 with 72k miles. It has the loaner software limit of 85 mph but it seems to also have much weaker off the line acceleration than I thought the 85s had. I was at 205 rated miles this morning ~80% and floored it at ~40-45 mph and instantly got the dashed power limit line. The car also has super limited regen at 90% SOC which seems very abnormal compared to my car where I don't think regen is really limited until 95% or so. At 50% the power limit is always there and at 77 mi rated there is a constant ~240kW power limit I think my car gets this closer to 42 mi rated at current ambient temps. I assume this is all battery based and not software (well, all software but based on battery characteristics that the software sees) I am pretty sure this has a B battery since is charges at ~116 kW

 

[apacheguy]

You should not see the dashed line at 80%. In mine, I don't see it until SOC is 50% or less.

 

[raphy3]

The car also has super limited regen at 90% SOC which seems very abnormal compared to my car where I don't think regen is really limited until 95% or so.

The good news is my regen send to always max out even at 90% SOC, so there that.

You should not see the dashed line at 80%. In mine, I don't see it until SOC is 50% or less.

Uh oh, potential red flag. Yeah I was getting dashed lines well above 80%, probably like 87-90 at the time (started driving at 90).

 

[strider]

How hot has it been in TN? It's getting hot here in OK. If you're doing repeated full throttle runs with warm/hot ambient temps the car won't be able to cool the battery and motor/PEM down enough in between runs and you'll get power limits.

In a perfect world you want a hot battery, hot tires, cold PEM, and cold motor. There is really no way to do this in a P85. W/ a PDL car you could put it in max battery heating mode and use tire warmers. That would get the tire and battery temps up w/o heating the motor and PEM.

What tires are on the car? Also, the 3.9/4.1 published times are at a drag strip. WAY better traction than a public road. TC on a Tesla is much better (ie harder to detect w/ your butt dyno) than an ICE car. ICE cars can only cut fuel/spark and apply the brakes. Both of those methods are very low frequency. A Tesla can add/delete power at the millisecond level so it tends to be smoother than the bucking feeling you have in an ICE when TC kicks in. I think the variation you're seeing could all be down to traction (and battery/motor/PEM temps).

 

[raphy3]

How hot has it been in TN? It's getting hot here in OK. If you're doing repeated full throttle runs with warm/hot ambient temps the car won't be able to cool the battery and motor/PEM down enough in between runs and you'll get power limits.

In a perfect world you want a hot battery, hot tires, cold PEM, and cold motor. There is really no way to do this in a P85. W/ a PDL car you could put it in max battery heating mode and use tire warmers. That would get the tire and battery temps up w/o heating the motor and PEM.

What tires are on the car? Also, the 3.9/4.1 published times are at a drag strip. WAY better traction than a public road. TC on a Tesla is much better (ie harder to detect w/ your butt dyno) than an ICE car. ICE cars can only cut fuel/spark and apply the brakes. Both of those methods are very low frequency. A Tesla can add/delete power at the millisecond level so it tends to be smoother than the bucking feeling you have in an ICE when TC kicks in. I think the variation you're seeing could all be down to traction (and battery/motor/PEM temps).

It has been varying. For the past couple weeks or so, it's been hot, up to 90 and maybe above a day or two. Then just yesterday it was nice and cool at like 77, maybe 80 the day before. So the dashed lines started showing up yesterday when it was cooler. It could be that I don't get on the interstate enough and should have seen it sooner (I usually commute on limited access road that has traffic and cops sometimes, but can choose to take the longer interstate route). So I agree that getting 3.9 probably ain't gonna happen on open roads, and 4.5 is pretty good. If I can keep that consistent I think I'll be happy. This new power limit kicking in at 90mph at 90% SOC scared me though. That showed up during my next phase of testing which is to check the top speed. Have not been able to get there yet due to traffic. Will need s more controlled environment, but it has me wondering if it will really be 130.

I take the point about continuous throttle and heating. I do push it to max power multiple times in a 17 mile trip, sometimes consecutively, so it's likely heating up the DU. Nonetheless, I need to get to the bottom of these dashed lines that are coming up too soon IMO. Car only has in the 30ks for miles.

Sorry forgot to add I have 21" wheels, summer tires. I agree the TC is incredible in terms of performance. I have also specifically seen the car limiting output power as the tires search for traction under certain conditions (hard acceleration out of a 90 deg turn). All in all I see the TC maintaining traction like 99% more than my old Saturn sky redline (but it was very fun to drive) or RX8. I don't worry at all in the rain.

 

[apacheguy]

Maybe you have high contactor resistance? Ask the SvC to see if your car has had the power switch upgrade.

 

[sorka]

Another minor update. I got the CANtact but now am waiting on my cable to use it. The plot has thickened: with the pedal to the floor at 95mph the power meter shows a dashed line at 310kw, twice yesterday. The service people told me that happens when the battery is being taxed too hard and the power output needs to be limited to protect it. However, if my battery is being taxed too hard such that the car can't go above 95mph, that seems like awfully abnormal behavior. I'll have to try to get it above 95 a few more times and see if the dashed line consistently appears. It'll be useful to have the CANtact output at that time too.

Edit to add: yup, totally consistent. I can get dashed lines on demand starting at 90mph if I try to accelerate hard at that speed. Demoed it to myself a few times. Is this normal? I was able to get over 100 and then had to slow down due to traffic.

The car can still do 155 MPH limited to 310KW. Are you saying it wouldn't go faster than 95? If so, then there's something wrong or it's been software limited to that speed.

Question, are you driving around in range mode? If so, turn it off if you plan to push the car. Range mode will limit how much active cooling is used which will cause the thermal protection to kick in a lot sooner.

 

[raphy3]

The car can still do 155 MPH limited to 310KW. Are you saying it wouldn't go faster than 95? If so, then there's something wrong or it's been software limited to that speed.

Question, are you driving around in range mode? If so, turn it off if you plan to push the car. Range mode will limit how much active cooling is used which will cause the thermal protection to kick in a lot sooner.

Sorry, I think I was being overly pessimistic or alarmist. I am able to get above 95. Today I saw 102. It seems right now my limiting factor is traffic as far as top speed goes. You're likely right and 310kw should still be plenty to get to top speed. FTR I believe I am expecting 130mph. No to range mode, but from time to time I wonder am I *sure* range mode, valet, etc. is off? Interestingly, the performance mode easter egg does not work for me. I think that didn't really affect the power though IIRC.

I charged to 100% today and it felt a little more powerful than the usual 80-90% I've been doing. Unfortunately didn't get to do 0-60 with 100% SOC. I can't wait to get my cable so I can start logging the power under all these conditions and really look at some hard data.

Maybe you have high contactor resistance? Ask the SvC to see if your car has had the power switch upgrade

Ok I haven't heard about this. Can you point me somewhere for more info? If there is some upgrade that reduces my internal resistance and gives me moar powa, I want it!

 

[AmpedRealtor]

The "performance" easter egg no longer works on my P85 either. I used to be able to hold down the Tesla logo and enter "performance" as the passcode, which would bring up different models on a drop down menu. No longer works.

 

[apacheguy]

Read this thread

Proactive Contactor Replacement

 

[Muffinman]

I have a 2013 P85 that somewhere along got power limitation after some 3 seconds of full throttle. Definetly was not like this before. Canbus readings show a flat 1170A current abruptly dropping to a little below 900A when this occurs, so this seems to be software controlled. Car has 17xxxx range VIN, and has not had its contactor replaced. No fault messages either.

 

[raphy3]

I have a 2013 P85 that somewhere along got power limitation after some 3 seconds of full throttle. Definetly was not like this before. Canbus readings show a flat 1170A current abruptly dropping to a little below 900A when this occurs, so this seems to be software controlled. Car has 17xxxx range VIN, and has not had its contactor replaced. No fault messages either.

yikes. these are the kind of things i want to look for with the cantact. these cpo p85s were lots more $ than regular 85s. you're kind of hoping they actually perform accordingly! how many miles do you have?

@apacheguy thanks, i will definitely look through that today.

so, i did record a video of 0-60, 120fps played at 30fps, so 4x slow motion to pinpoint the timing. however, it is hard to find movie players that count subseconds. using a stop watch i get 4.15s with likely 100ms accuracy at 80%soc. that is my best time yet, but im still suspicious of this method since relies on human reaction time. id say 4.3 sec on high side. i'll try to time the video more accurately.

ftr this is safe with the phone mounted on the wheel column, hands free. video is started when car is at rest and stopped when car is brought back to rest. no more dngerous than tapping your phone screen when waiting at a light.

 

[Muffinman]

Located in Norway having 123.000km on it. Not sure when this limiting stuff was introduced as my wife drives the car daily, but i guess this has been added through OTA update some time. Neither of us drives the car very hard either so who knows when. The 2015 85D I drive does not do this; it keeps the battery current @Max for as long I dare to floor it.
I suspect Tesla has introduced this to avoid this contactor/power switch failing, saving warranty expenses. If so it would not be the first time they change things secretly to "fix" design flaws.

 

[Muffinman]

Also, this probably does not affect 0-60 times much (although throttle response was severely reduced after the drive unit scandal) as power/current starts very low from standstill and then increases to max at some speed. Full throttle from some speed triggers limit very quickly though.