Cooling the Performance Model 3 On Track – An Overview of Our Modified Heat Exchangers

[juliusb]

There is no way that you can do 2 hot laps without overheat on the Ring. I have all possible cooling except water on radiators. 3 extra large radiators for front and back with high current fans and direct frontal airflow.

My oil temps are fine, battery is fine. It still pulls power back at 6:30 if you go for 7:30 BTG. And that adds 10-15 seconds to the timer. Also you consume 60% at such pace within one lap.

You might be able to do one 8:00 BTG and another 8:20 on a single charge. If power wouldn't drop that much with speed and no power limits, it can do ~ 7:05 BTG, but long straights killing it. It's too big track for it.

Salzburgring is better place for it. 2 hot - 1 cold is sustainable sequence with cooling and brake mods to do slightly more than 20 minutes total per charge and you have chargers on the track.

Thanks Mash, I knew I could count on your feedback given your wast experience in that field and racetracks.

After studying a lot of YT-vids (including yours with Misha at Apex) and forums-posts, I hoped for 2 fast (not max-hot) Nürburgring laps with the help of the mysterious software tweak announced by Chris aka MasterC17. Of course after applying hardware cooling mods like f/r DU oil cooler & HV battery loop water radiator.

Combined with a mild power limiting from the start via MPP cooling party controller this should be achievable with 2 times low 08:xx BTG without trying to set new records, just enjoying a more constant flow and conserving M3s hardware a bit...

Maybe this does not make sense to you, but the quick but smooth ride was always my approach. From MTB downhills to go-kart tracking or enduro and street bike touring to 4WDing in the mountains. I prefer consistency and flow to a more aggressive/abrupt style, that's me having fun with less risk and wear...

Bye Julius

 

[MasterC17]

Thanks Chris, your linked essay is pure gold and delivers essential missing links for further understanding the whole plot.

At first I tought, if we only could cool down all the overheating components and liquids, power limits should disappear. Now I learned, even if we applied all the cooling, the constantly high amperage draw = high C-rates remain the limiting factor for BMS, inverters & cells. Makes absolute sense after dissolving some tunnel vision / focussing on just cooling...

My second missing link is understanding the advantage and way of working of MPPs power-limiting version of the Cooling Party Controller you mentionend in your essay linked above and in the YT-Vid with Larry Chen. Even if it's not what I and assumingly most of the members of this thread were looking for - a power limit to begin with. But it could make sense to rather have ~20 constantly driven minutes on track, then starting in full attack mode and "limping home" after a shorter time.

I also found it appealing that with applying some power limit via CPC, effiency of power usage will increase, cause little power cuts would cause disproportionate higher energy/heat loss savings. Thus, less charging per track time unit needed.

Furthermore I learned in your essay "evaluating the M3 as a track car in 2023" that MS plaid's battery cell and drive train can sustain high discharging longer than M3s. Which leaves me awaiting the implementation of this next-gen-tech in our more compact, lightweight and inexpensive M3-platform. Or/and waiting for used MS Plaid prices falling to affordable levels...

Please let me ask you this: in your essay "thermal limits of the M3/Y" you point to "MPP’s HV Battery Radiator". Your article was written 13 months before, so when may we expect the launch of this product? Ditto the front DU oil cooler?

Best whishes, thanks and cheers! Julius

The MPP Cooling Party Controller I think is great because it allows you to be far more consistent with your laps without giving up a lot of speed.

Here's an example of a ~240KW limit. As you can see, the current does not change throughout the 17-minute session. Normally, you'd be losing power around the 7-minute mark at this track. You're probably losing about 3-seconds per lap (laps around 1:45), but I think it's well worth it.

The Plaid is truly on a different level. It can discharge 50% more power for three times as long. Unfortunately, it's not as enjoyable to drive and is still 700lbs heavier.

A front drive unit oil cooler turned out to be unnecessary - I don't think it will help you in any tangible way.

Contact MPP directly for more details on the radiator.

If you're willing to do all of the cooling modifications, even turning the power down to something like 270kW should still net you close to double the track time or so.

 

[Mash]

The MPP Cooling Party Controller I think is great because it allows you to be far more consistent with your laps without giving up a lot of speed.

Here's an example of a ~240KW limit. As you can see, the current does not change throughout the 17-minute session. Normally, you'd be losing power around the 7-minute mark at this track. You're probably losing about 3-seconds per lap (laps around 1:45), but I think it's well worth it.

View attachment 1040219

The Plaid is truly on a different level. It can discharge 50% more power for three times as long. Unfortunately, it's not as enjoyable to drive and is still 700lbs heavier.

A front drive unit oil cooler turned out to be unnecessary - I don't think it will help you in any tangible way.

Contact MPP directly for more details on the radiator.

If you're willing to do all of the cooling modifications, even turning the power down to something like 270kW should still net you close to double the track time or so.

I disagree about front oil cooler. Front motor is hot. It throws that heat into the coolant. From coolant it goes everywhere. My front coolers push front oil temperature 20C lower. That can't be nothing.

 

[juliusb]

The MPP Cooling Party Controller I think is great because it allows you to be far more consistent with your laps without giving up a lot of speed.

Thanks to your explanations I did realize that now. Even if it annoys me a bit to give up some power, it seems to be an appropriate compromise in this state of development.

Here's an example of a ~240KW limit. As you can see, the current does not change throughout the 17-minute session. Normally, you'd be losing power around the 7-minute mark at this track. You're probably losing about 3-seconds per lap (laps around 1:45), but I think it's well worth it.

Thanks, very impressive data logging! Makes me wanting the MoTeC even more. Shame it's so expensive...

17 min. without power loss are great and what I'd like to see. Although loosing 3 s on a 1:45 track - ouch. Not a minor loss...

The Plaid is truly on a different level. It can discharge 50% more power for three times as long. Unfortunately, it's not as enjoyable to drive and is still 700lbs heavier.

Very happy about the Plaid's improved thermal durability. And sad to read you feel it's much less fun to drive. Mind to elaborate why?

A front drive unit oil cooler turned out to be unnecessary - I don't think it will help you in any tangible way.

Interesting to read from the cooling master himself, did not expect that. So no extension of tracktime by adding the front DU oil cooler, when rear DU oil cooler + front HV battery loop water radiator are present + fully activated settings of CPC and/or Tesla track mode?

What about installing the front DU oil cooler just to reduce thermal burden & wear on front DU, inverter and hydraulic oil? To reduce risk of failure and possible costs, and extend service intervals for oil changes?

Contact MPP directly for more details on the radiator.

Will do! Did you receive the necessary parts for your prototype from MPP, or did you buy them elsewhere in coordination with MPP?

If you're willing to do all of the cooling modifications, even turning the power down to something like 270kW should still net you close to double the track time or so.

Yes I am willing to install all the sensible cooling hardware and SW-mods (CPC etc.). Which leads us to:

Pls would you comment on your "secret" mysterious SW-mod to extend high c-rates discharge / tracktime you mentionend a long time ago?

What about your battery penthouse mod? No longer track times after applying it?

What do you mean exactly with "do all of the cooling mods"? "Only" Rear DU oil cooler + Battery Radiator + MPP CPC? Or more?

And yes, the outlook to be able to play with different CPC power limit settings depending on track, weather, tires, goals etc. sound like tech geeks paradise to me I would start with 294 kW = 400 hp, because that's the magic number i would love to see as often as possible at least. And climbing down gradualy if necessary...

Final details:

Can we apply all the OEM Tesla track mode settings & all the MPP CPC mods at the same time?

MPP partybox & CPC are necessarly 2 separate units? Or can their functionality be merged into on box? If not, can they be used simultaneously?

We're getting there...

 

[juliusb]

I disagree about front oil cooler. Front motor is hot. It throws that heat into the coolant. From coolant it goes everywhere. My front coolers push front oil temperature 20C lower. That can't be nothing.

That would be my first response either. But we should let Chris elaborate on that, as he gained a lot of experience and data in colab with MPP.

Is it correct that you did not install an extra HV battery loop water radiator, as Chris/MasterC17 did? Maybe he referred to the combination: only rear DU oil cooler + extra battery water radiator are powerful enough, cause it gives the AC-compressor more reserves to handle the remaining heat?

 

[Mash]

That would be my first response either. But we should let Chris elaborate on that, as he gained a lot of experience and data in colab with MPP.

Is it correct that you did not install an extra HV battery loop water radiator, as Chris/MasterC17 did? Maybe he referred to the combination: only rear DU oil cooler + extra battery water radiator are powerful enough, cause it gives the AC-compressor more reserves to handle the remaining heat?

I didn't change my radiator. I thought that oil is hotter, so it works better as a cooling medium. I still have hot radiators, so I plan to put water spray on them.

EVs are not that hot, so its much harder to cool them. Heat pump based model 3 are even harder to cool since they don't have an air condenser and everything goes to the coolant, which is not hot enough to be effective heat energy transport.

Anyway, I'm also interested why @MasterC17 thinks that front oil cooler is not needed.

 

[juliusb]

EVs are not that hot, so its much harder to cool them. Heat pump based model 3 are even harder to cool since they don't have an air condenser and everything goes to the coolant, which is not hot enough to be effective heat energy transport.

I see your point. When Delta T is not high (enough), we can increase P (cooling performance) with higher volume flow on the primary side, more air flow (inlet, ducting, fan) on the secondary side, and larger heat-exchanger surface. The 2nd and 3rd seem doable, which I'd like to implement.

According to @MasterC17 testimonial his extra radiator capped cell temps at 50-52°C vs. max. of 62°C before. Although we don't know the ambient temps Chris run his tests & data logging - that kind of cooling would be enough, right? Provided this would still work in US and European summers on glowing asphalt. Not so much Delta T left there for sure...

 

[MasterC17]

Thanks to your explanations I did realize that now. Even if it annoys me a bit to give up some power, it seems to be an appropriate compromise in this state of development.

Thanks, very impressive data logging! Makes me wanting the MoTeC even more. Shame it's so expensive...

17 min. without power loss are great and what I'd like to see. Although loosing 3 s on a 1:45 track - ouch. Not a minor loss...

It's not a minor loss, but it really depends on what you're after. If that's improving as a driver and learning the track better, it's a compromise well-worth taking.

Very happy about the Plaid's improved thermal durability. And sad to read you feel it's much less fun to drive. Mind to elaborate why?

Mostly it's just the steering ratio - the Model 3 is quick and nimble, the S feels like a boat. Plus, an extra ~700lbs is not insignificant when it comes to driving dynamics, and the car is very long.

Interesting to read from the cooling master himself, did not expect that. So no extension of tracktime by adding the front DU oil cooler, when rear DU oil cooler + front HV battery loop water radiator are present + fully activated settings of CPC and/or Tesla track mode?

What about installing the front DU oil cooler just to reduce thermal burden & wear on front DU, inverter and hydraulic oil? To reduce risk of failure and possible costs, and extend service intervals for oil changes?

In that 17-minute example above the front drive unit oil peaked at 56C (44C after 10 minutes). The rear runs significantly more current, and as such gets much hotter. Since the front DU Oil is only slightly higher than the Battery (~2C), I don't see it as causing any issues. There's certainly no harm in adding a cooler, it's just overkill.

Will do! Did you receive the necessary parts for your prototype from MPP, or did you buy them elsewhere in coordination with MPP?

The parts came from MPP directly.

Yes I am willing to install all the sensible cooling hardware and SW-mods (CPC etc.). Which leads us to:

Pls would you comment on your "secret" mysterious SW-mod to extend high c-rates discharge / tracktime you mentionend a long time ago?

What about your battery penthouse mod? No longer track times after applying it?

Basically, it's very difficult to crack the BMS. There's also significant liability along with it. I wouldn't expect anything to change in this regard. E.g. it's not viable.

The penthouse modification ultimately did not make the difference we were expecting. There was years of trial and error involved in this project.

What do you mean exactly with "do all of the cooling mods"? "Only" Rear DU oil cooler + Battery Radiator + MPP CPC? Or more?

And yes, the outlook to be able to play with different CPC power limit settings depending on track, weather, tires, goals etc. sound like tech geeks paradise to me I would start with 294 kW = 400 hp, because that's the magic number i would love to see as often as possible at least. And climbing down gradualy if necessary...

Battery Radiator, RDU Oil Cooler, and CPC, yes.

Final details:

Can we apply all the OEM Tesla track mode settings & all the MPP CPC mods at the same time?

MPP partybox & CPC are necessarly 2 separate units? Or can their functionality be merged into on box? If not, can they be used simultaneously?

We're getting there...

Yes, Track Mode integrates with the CPC.

CPC and PB are two separate units. They integrate on different parts of the CAN network. They can be used simultaneously.

 

[juliusb]

@MasterC17 thanks for your replies, they are very appreciated. The whole M3P tracktool package seem more understandable to me now, great effort.

@MountainPass dear MPP team, pls would you inform us when your M3 HV battery loop radiator kit is going to be launched?

Thanks & cheers! Julius from Salzburg, Austria

 

[juliusb]

@MountainPass dear MPP team, pls would you inform us when your M3 HV battery loop radiator kit is going to be available?

Thanks & cheers! Julius from Salzburg, Austria

 

[brianman]

12 min. track time before power loss

I put it more at 10-11 but yeah. Same with my 2018.

 

[juliusb]

I put it more at 10-11 but yeah. Same with my 2018.

Unfortunately due to Mash's testimonial on a very fast track like Nordschleife it's even less:

There is no way that you can do 2 hot laps without overheat on the Ring. I have all possible cooling except water on radiators. 3 extra large radiators for front and back with high current fans and direct frontal airflow.

My oil temps are fine, battery is fine. It still pulls power back at 6:30 if you go for 7:30 BTG. And that adds 10-15 seconds to the timer. Also you consume 60% at such pace within one lap.

You might be able to do one 8:00 BTG and another 8:20 on a single charge. If power wouldn't drop that much with speed and no power limits, it can do ~ 7:05 BTG, but long straights killing it. It's too big track for it.

Salzburgring is better place for it. 2 hot - 1 cold is sustainable sequence with cooling and brake mods to do slightly more than 20 minutes total per charge and you have chargers on the track.

So for me there really is enough incentive to pull all tricks to maximize track time with M3P.

And can't wait to learn how much better the recently launched new M3P would be on Nordschleife with all the cooling mods @MasterC17 mentioned = rear DU oil cooler + battery radiator + cooling party controller + capping maximum power/torque + maximum of precooling before launch.

Should't we open a new thread regarding only the new M3P and track experience / mods?

 

[brianman]

Should't we open a new thread regarding only the new M3P and track experience / mods?

Sounds good to me.

 

[MasterC17]

I put it more at 10-11 but yeah. Same with my 2018.

It's very dependent on the track, car setup, and how fast you are.

For example, this weekend on a track with a lot of low-speed/high-current corner exits I got it to hit current limiting in only ~6 minutes with one slow warm-up lap.

 

[MasterC17]

Should't we open a new thread regarding only the new M3P and track experience / mods?

FWIW I don't expect much to change. The modifications will pretty much all carry-over, and things like the current limiting aren't going to change, as the HVB hasn't changed. In fact, the cars built outside of the United States probably won't be any faster than the outgoing Performance 3 due to the battery cells. Even so, I don't expect a dramatic change in lap times for the US version.

The new 3 is without a doubt a much more refined car, and a better daily driver (less wind/road noise, more compliant suspension, more luxurious, etc). It's an incredible value (at least in the US), at half the cost of a comparable BMW M3 after tax credits. But, it's not a notable improvement as far as a lapping car is concerned.

But, I ordered one - lol.