P85 modded to be a P85 w/Ludicrous

[wk057]

So, I just finished some initial testing of my latest modification to the yellow P85 (the one that has retrofitted autopilot hardware). Haven't gotten a lot of pics or videos together yet (roads have been wet from melting snow, so not great conditions for testing), but I can't resist sharing some initial details.

So far the car is a ~570HP RWD monster that desperately needs wider rear tires. It doesn't even have the staggered rims, so I'm putting this all through 245's at the moment and traction control stays on up to like 45 MPH. lol.

The car and everything in it are now running P85D firmware. The battery has been upgraded to a P85D Ludicrous pack. The car does not actually have a front motor, however. The front motor is being emulated by custom hardware and software that essentially tricks the car into thinking there is a front motor and that all of the power needs to go to the rear... and it does exactly that.

The performance rear drive units appear to have a max current of around 1400A. Ludicrous allows ~1520A, so even with HVAC on and such the motor can still max out.

In my testing at around 90% SoC and battery at about 32C the power maxed out at about 426kW. I plan on trying Max Battery Power @ 100% charge. Oh, and launch mode works too.

I finished up some code to make the car happy enough to not display any errors at all finally, but by then the pack was down to about 50% SoC. Did a few more test runs and snapped some photos of the dev readouts screen.

(Even at 50% SoC was still getting ~380kW/508 HP)


Hopefully roads dry up and I can grab the VBOX tomorrow for some testing at 100% SoC and a warm pack.

More soon.

(Yes, it's technically the wife's car.... although she uses the X mostly now)

Jason Hughes on Twitter

Edit: Oh, and um... I may plan on offering this modification as a service at some point to P85/P85+ folks.

Edit: Video:

 

[silentsnow31802]

How do you not work for Tesla? The stuff you do amazes me.

 

[mdevp]

Speechless

 

[cryptyk]

Any reason you can't put a second P motor in the front?

 

[SD_Engnr]

Edit: Oh, and um... I may plan on offering this modification as a service at some point to P85/P85+ folks.

I fully hoped you would say this. There seems to be a lack of tuning options for EV's and you could be on to something awesome.

 

[silentsnow31802]

Any reason you can't put a second P motor in the front?

The unibody between the D and non D models are different. You cannot put a motor in the front of a single motor body without some crazy modification.

 

[Evee]

Absolutely amazing. Keep it up!

 

[Andyw2100]

To heck with the power, etc. I'm just impressed you were able to make the display car yellow, to match your wife's wrap!

 

[SageBrush]

I appreciate the software hack but how do you convince yourself that the drivetrain has reasonable components to support Ludicrous mode over time ?

 

[wk057]

How do you not work for Tesla? The stuff you do amazes me.

I've been offered positions at Tesla, but I refuse to move to California. Apparently that's a deal breaker. Besides, probably wouldn't be as much fun.

Any reason you can't put a second P motor in the front?

The front frame rails are totally different on the RWD cars. It would take extensive modification to do so. Certainly not impossible, but would need way more power available to even bother. A P100D cant even max out a small front and large rear, let alone two large DUs.

I appreciate the software hack but how do you convince yourself that the drivetrain has reasonable components to support Ludicrous mode over time ?

Not just software hacks. The pack is actually a Ludicrous pack now. The motor is a recent warranty swap that happened to be a P85D compatible unit that is the same revision as was in my P85D. So, overall, should be perfectly fine. Definitely kissed those warranties goodbye, though.

 

[Kristoffer Helle]

I like this

 

[Andyw2100]

Definitely kissed those warranties goodbye, though.

I'd love to see the service personnel's reaction if you brought it in some time, as if it was just your plain old vanilla P85.

 

[SageBrush]

The pack is actually a Ludicrous pack now. The motor is a recent warranty swap that happened to be a P85D compatible unit that is the same revision as was in my P85D. So, overall, should be perfectly fine. Definitely kissed those warranties goodbye, though.

This is what I was thinking about ..

The P90D retrofit costs the full $10,000, plus whatever taxes and labor costs are involved with its installation. The upgrade, as Electrek details it, replaces the standard fuse with an "advanced smart fuse" that monitors and manages current more precisely (to the millisecond). The main steel battery pack contactor gets replaced with the same Iconel superalloy that Elon Musk's other venture, SpaceX, uses for its SuperDraco rocket engine. Combined, the changes increase the maximum output from 1,300 to 1,500 amps, which translates to better performance from the car.

 

[Canuck]

Very impressive.

Edit: Oh, and um... I may plan on offering this modification as a service at some point to P85/P85+ folks.

If the wink doesn't mean this is joke, I sure hope you have a good insurance policy that covers this type of risk.

 

[wk057]

I'd love to see the service personnel's reaction if you brought it in some time, as if it was just your plain old vanilla P85.

Definitely going to be a fun visit next time I need something from them...

This is what I was thinking about ..

This car has the new contactors and pyrofuse now.

 

[wk057]

Very impressive.

If the wink doesn't mean this is joke, I sure hope you have a good insurance policy that covers this type of risk.

Insurance?! What's that?

On a serious note, obviously would have to get some ducks in a row to actually make that happen... appropriate insurance would certainly be one of those ducks.

 

[BLKTSLA]

Good stuff here, they seemingly abandoned the P85/85+ so this is good to hear. Question, with all the software emulation done to make the system "think" it has a front motor and to send the power to the rear, how do you know the power outputs are not also emulated? In other words, maybe its just showing that power output based on the emulation and its not actually putting out that much via the rear motor? My understanding is that the rear motor of the PD's(570hp) is different than the one in the PRWD's (417hp), no?

Also, is it possible to make a P85/85+ into a P90/90+ with the 90L pack?

 

[wk057]

Good stuff here, they seemingly abandoned the P85/85+ so this is good to hear. Question, with all the software emulation done to make the system "think" it has a front motor and to send the power to the rear, how do you know the power outputs are not also emulated? In other words, maybe its just showing that power output based on the emulation and its not actually putting out that much via the rear motor? My understanding is that the rear motor of the PD's(570hp) is different than the one in the PRWD's (417hp), no?[

The dev screen readouts are actually directly from the battery BMS and the rear motor inverter. Nothing emulated there. The emulation comes in with my custom hardware that sits on the CAN bus and pretends to be a small front drive unit... but it can't actually pull power from the battery, so that current number isn't affected.

Here's a pic of my "front motor" from some testing earlier in the day (has since been cleaned up a bit):

All of the performance rear drive units are essentially the same regardless of D. There have been some minor revisions related to autopilot and dual motor, but for the most part they're interchangeable.

Also, is it possible to make a P85/85+ into a P90/90+ with the 90L pack?

In theory. I've not actually tried this, but I don't see why it wouldn't be possible.

 

[FlatSix911]

Congratulations on your mods ... well done!

 

[cryptyk]

Here's a pic of my "front motor" from some testing earlier in the day (has since been cleaned up a bit):

Where do you get your one-off boards printed? I've been using OSH park, but the shipping time of 3-4 weeks isn't ideal sometimes when you want to iterate quickly...