Pushrods&Capacitors

Well-Known Member
First Name
Brian
Joined
Jun 24, 2021
Messages
624
Reaction score
1,253
Location
Round Rock, TX
Vehicles
‘21 4X, ‘14 SS Sedan tuned, ‘17 WRX tuned
Occupation
Analyst
Country flag
Who is the user in the non-GT with the trap around 103-104? I can't find it and want to enter that data! :) can anyone link me, please?
@mtxpert ran their 4X at the track but I forgot exact numbers. Car and Driver: [email protected] in Feb. issue I think, [email protected] in July issue? Motor Trend: [email protected]

https://www.caranddriver.com/news/a36877450/2021-ford-mustang-mach-e-ev-of-the-year/

https://www.motortrend.com/reviews/2021-ford-mustang-mach-e-first-test-review/
Advertisement

 

harrysiii

Well-Known Member
First Name
Harry
Joined
May 13, 2020
Messages
432
Reaction score
540
Location
New Hampshire
Vehicles
'21 MME GTPE DMG; '10 G37xS; '18 Pacifica Limited
Country flag

Brofessional

Well-Known Member
Joined
Apr 19, 2021
Messages
143
Reaction score
328
Location
Midwest
Vehicles
20 Veloster N, 12 Accord, 18 Yukon, 21 Mach E GT
Country flag
Do you have enough information about the MME GT to calculate the theoretical acceleration of the car up to 1/4 mile, and what the splits theoretically could be? If so, can you tell if the software is dampening the acceleration at a certain point or if the observed times are the theoretical maximum? Or do other things come into play at high RPMs that make it too difficult to calculate?
Not at 1/4 mile. Published power curves for most Teslas usually have constant power starting to trail off at around 70-80 mph or so, well before 1/4 trap speeds, which is perfectly normal for an EV use case. You can design EVs where the constant power zone extends beyond 1/4 mile speeds which is what you see with the plaid curve, but it increases cost either via more motors and/or more robust cooling and driveline components.

But comparing single reduction gear DC motors to between EVs is easy, much easier than it ever was with combustion engines. Model Y which is slightly lower power but also slightly lower weight with almost the exact same final drive ratio should have almost the exact same curve. And up until a certain point it does. But whether for mechanical or software reasons, constant power does not go as deep into RPMs in the Mach E. The fact that acceleration at higher RPMs seems to improve if peeps aren't starting from a dig implies it's not mechanical.

But whether that presumed software limitation is for some BS warranty or making room for future variants or whether it's to keep you from lighting yourself on fire has yet to be determined, because Ford hasn't told us yet.
 

Mach C

Member
Joined
May 20, 2021
Messages
6
Reaction score
10
Location
Florida
Vehicles
Lexus Hybrid, GT Performance (ordered)
Country flag
Im trying, trying to keep positive untill proven otherwise, but the early reports of dismal GT performance and the fact that the car was released into the wild and on the track -lame puts to question Fords intent and capabilities.
So, its not a Mustang. Its not a GT. Its not Ford Performance. Its not even a Rabbit. It can not compete with other electrics or gas. Certainty not Tesla- its main competitor.
If the early specs are true, this Ford Mustang Mach e GT Performance edition is actually an electric Taurus that will have trouble passing around a pack of semi trucks on I95 going 80mph- come box in my $80k Ford GT Performace sports car. Watch the F150 Lightning brick blow my (handel less) doors off. I dont think my GTP could pass my Mom's Lexus RX on the highway. Bright red painted Brembo? This car has no need for high performance brakes because the motors will slow me down.
This is not race track letdown. This looks to be a every day highway slug. Now add Passing Speed anxiety to Range anxiety. 0-60? I have zero desire to jackrabbit first into an intersection. Thats a race to get T-Boned. Kid stuff.
I dont want a very nice Taurus hatchback. I want an electric Mustang and I will pay extra for a GT Ford Performance sports car.
Is this it? Please make it so!
Ford promised Performace beyond T-Bone racing, a GT badge and red brakes. But what exactly have they let out of the stable (horse or bull) and is it a mistake to be quickly fixed or a new pay to play marketing plan? Not yet we hope...
Is Deloitte marketing analytics department working on it or top hw/sw engineers?
(Perception or Performance).
Its all about Trust now and if this is their Mustang much less their GT, then Ford Performance is over. Who would trust a $125k Shelby electric, etc?
This is Ford's moment. Edsel or Grand Prix? Taurus or Mustang?
America needs a real electric Mustang- now. We want to believe.
We are still here with you.
Come on Ford, show us and the world what you've got.
Lets ride!
 

EVmodeler

Well-Known Member
First Name
Doug
Joined
Oct 30, 2020
Messages
94
Reaction score
232
Location
SW Virginia
Vehicles
Mach-E AWD ER IB
Occupation
Engr Prof
Country flag
See an acceleration model for the ER AWD and RWD here
https://www.macheforum.com/site/threads/mach-e-extended-range-acceleration-modeling.2177/
The 1/4 mi time predicted is not too far off considering the approximations.
There is also a RWD ER dyno test that shows constant power to near top speed.
See https://www.macheforum.com/site/thr...o-test-results-375-hp-409-ft-lbs-torque.3737/

Of course none of this is for GT or GTPE, but it does show what can be done with a pretty simple model.

As much as I appreciate the "traction" this is getting, the dude obviously doesn't know what he's talking about with field weakening being the reason torque falls off.

HP = (torque x RPM)/5252

So if you keep power constant (which just happens to be doable in an electric motor in part because of field weakening) what the F does does this clown THINK is going to happen to torque as RPMs increase? The thing could run on GD unicorn farts and it would see the exact same linear reduction in torque as RPMs increased provided power was held constant.

Not only that, but MANUFACTURERS LITERALLY GIVE YOU THE CONSTANT POWER NUMBER. So we can mathematically calculate exactly what the torque will be at any given RPM, and we can also incorporate vehicle weight, drive ratios, and tire diameter to calculate--and I cannot stress this enough--WHAT THE ACCELERATION SHOULD BE AT ANY GIVEN RPM.

However, there are limitations as to the range of rpms over which weakening can be used to keep back EMF at its limit and thus provide constant power, so eventually power starts to fall off. THAT is where you start to get separation of EVs as they don't adhere to simple equations any longer, and it is currently where we find ourselves with the mach e's performance vs the competition.

All these posts/articles/journalists talking about flux and how "torque just falls off" and "needs an induction motor" or a "2nd gear" or whatever other shit spills out of their brains. JFC the education system in this country sucks.

I'm gonna sit down now.
 
Last edited:

jasaero

Active Member
First Name
Jake
Joined
Sep 2, 2021
Messages
29
Reaction score
23
Location
Texas
Vehicles
2016 Colorado Diesel/2017 Chrysler Pacifica Hybrid
Occupation
Engineer
Country flag
As much as I appreciate the "traction" this is getting, the dude obviously doesn't know what he's talking about with field weakening being the reason torque falls off.

HP = (torque x RPM)/5252

So if you keep power constant (which just happens to be doable in an electric motor in part because of field weakening) what the F does does this clown THINK is going to happen to torque as RPMs increase? The thing could run on GD unicorn farts and it would see the exact same linear reduction in torque as RPMs increased provided power was held constant.

Not only that, but MANUFACTURERS LITERALLY GIVE YOU THE CONSTANT POWER NUMBER. So we can mathematically calculate exactly what the torque will be at any given RPM, and we can also incorporate vehicle weight, drive ratios, and tire diameter to calculate--and I cannot stress this enough--WHAT THE ACCELERATION SHOULD BE AT ANY GIVEN RPM.

However, there are limitations as to the range of rpms over which weakening can be used to keep back EMF at its limit and thus provide constant power, so eventually power starts to fall off. THAT is where you start to get separation of EVs as they don't adhere to simple equations any longer, and it is currently where we find ourselves with the mach e's performance vs the competition.

All these posts/articles/journalists talking about flux and how "torque just falls off" and "needs an induction motor" or a "2nd gear" or whatever other shit spills out of their brains. JFC the education system in this country sucks.

I'm gonna sit down now.
Not sure you caught this in other thread...but I finally came across and OLD Wally Ripple write up that suggest induction may tend to be better for "performance" for awhile. I hadn't read this in ages and could remember all the particulars of his reasoning as I don't design electric motors.

But am sure these are the reasons Tesla kept induction in the mix until recently rather than JUST cost. It's a performance thing and possibly even efficiency when driven hard.

https://www.tesla.com/blog/induction-versus-dc-brushless-motors
 

pt19713

Well-Known Member
Joined
Nov 16, 2020
Messages
456
Reaction score
406
Location
.
Vehicles
.
Country flag
Not sure you caught this in other thread...but I finally came across and OLD Wally Ripple write up that suggest induction may tend to be better for "performance" for awhile. I hadn't read this in ages and could remember all the particulars of his reasoning as I don't design electric motors.

But am sure these are the reasons Tesla kept induction in the mix until recently rather than JUST cost. It's a performance thing and possibly even efficiency when driven hard.

https://www.tesla.com/blog/induction-versus-dc-brushless-motors
They also use it for pre-conditioning the battery in colder temperatures, in additionfor the reasons listed in the article. They utilize that extra heat and inefficiency to help warm the battery for L3 charging. Previously, the S and X used dedicated battery warmers, which required significant energy from the battery. When the 3 and Y are in motion and pre-conditioning is needed, it only requires 2 kW.
 

Brofessional

Well-Known Member
Joined
Apr 19, 2021
Messages
143
Reaction score
328
Location
Midwest
Vehicles
20 Veloster N, 12 Accord, 18 Yukon, 21 Mach E GT
Country flag
See an acceleration model for the ER AWD and RWD here
https://www.macheforum.com/site/threads/mach-e-extended-range-acceleration-modeling.2177/
The 1/4 mi time predicted is not too far off considering the approximations.
There is also a RWD ER dyno test that shows constant power to near top speed.
See https://www.macheforum.com/site/thr...o-test-results-375-hp-409-ft-lbs-torque.3737/

Of course none of this is for GT or GTPE, but it does show what can be done with a pretty simple model.
Dude. Nice!

Ok so can you educate me here? RWD unit looks just like it "should" for high torque extended constant power to near max. As I understand it, compared to higher power, lower torque (and usually smaller) units, acceleration curves should cross at some equivalent speed with the higher power units demonstrating increased acceleration with increasing RPMs. I also am under the impression that a lower torque, higher power unit will typically hit the equivalent speed at a shorter distance. So in my mind all of this would make sense if Ford is using higher torque extended constant power to hit the same 3.5 to 60 in a heavier vehicle compared to the model Y, with lower trap speeds and less acceleration after 60.

BUT...MYP and GTPE have essentially the same torque figures, GTPE has a HIGHER power rating, and people seem to be getting better acceleration after 60 if they don't start from 0--none of which makes sense unless there is some software interference. Correct? Are we missing something that would provide a simpler explanation?
 

Brofessional

Well-Known Member
Joined
Apr 19, 2021
Messages
143
Reaction score
328
Location
Midwest
Vehicles
20 Veloster N, 12 Accord, 18 Yukon, 21 Mach E GT
Country flag
Not sure you caught this in other thread...but I finally came across and OLD Wally Ripple write up that suggest induction may tend to be better for "performance" for awhile. I hadn't read this in ages and could remember all the particulars of his reasoning as I don't design electric motors.

But am sure these are the reasons Tesla kept induction in the mix until recently rather than JUST cost. It's a performance thing and possibly even efficiency when driven hard.

https://www.tesla.com/blog/induction-versus-dc-brushless-motors
My man. Just go read some stuff.

Your occupation says engineer which, if true, means you are more than adequately educated to accurately interpret the absolute MOUNTAIN of published literature on the subject of EM field generation and electric motors. Induction has its uses, as we've already discussed, but it is NOT well suited for high RPM torque generation. It's just not.

I'm here trying to explain the physics as well as I understand it, and your replies ubiquitously refer to how you "feel" and how you're "sure" that Tesla's use of IMs is "a performance thing," without bothering to learn why your feelings are completely backwards mathematically.
 

Frankie

Well-Known Member
Joined
Nov 17, 2019
Messages
372
Reaction score
547
Location
Nevada
Vehicles
2012 Mustang
Country flag
Dude. Nice!

Ok so can you educate me here? RWD unit looks just like it "should" for high torque extended constant power to near max. As I understand it, compared to higher power, lower torque (and usually smaller) units, acceleration curves should cross at some equivalent speed with the higher power units demonstrating increased acceleration with increasing RPMs. I also am under the impression that a lower torque, higher power unit will typically hit the equivalent speed at a shorter distance. So in my mind all of this would make sense if Ford is using higher torque extended constant power to hit the same 3.5 to 60 in a heavier vehicle compared to the model Y, with lower trap speeds and less acceleration after 60.

BUT...MYP and GTPE have essentially the same torque figures, GTPE has a HIGHER power rating, and people seem to be getting better acceleration after 60 if they don't start from 0--none of which makes sense unless there is some software interference. Correct? Are we missing something that would provide a simpler explanation?
I don't think it's really accurate to call it "software interference."

I.e. if you can turn the boost up to 20 psi with just a tune, does that mean the factory tune was "interfering" with the engine by only running 12 psi?

Ford tuned the car this way for a reason and the more time goes on the more likely I think it is that they're not going to improve on it much, if any.
 

jasaero

Active Member
First Name
Jake
Joined
Sep 2, 2021
Messages
29
Reaction score
23
Location
Texas
Vehicles
2016 Colorado Diesel/2017 Chrysler Pacifica Hybrid
Occupation
Engineer
Country flag
My man. Just go read some stuff.

Your occupation says engineer which, if true, means you are more than adequately educated to accurately interpret the absolute MOUNTAIN of published literature on the subject of EM field generation and electric motors. Induction has its uses, as we've already discussed, but it is NOT well suited for high RPM torque generation. It's just not.

I'm here trying to explain the physics as well as I understand it, and your replies ubiquitously refer to how you "feel" and how you're "sure" that Tesla's use of IMs is "a performance thing," without bothering to learn why your feelings are completely backwards mathematically.
Well like I said I don't design motors or sparky control systems for them, and don't have tons of time to devote to understanding all the ins and outs of the different control regimes you are forced into with the two different motor designs. But Wally was was into this stuff and seemingly is part of his expertise. Not going to try and catch upto Wally after I heard his take years ago...just took it too heart.

Not that he is right or anything...but it generally sounds like the b-field adjustability which is really what I was trying to verbalize without really knowing all the terms for these designs, is what gives you tools to increase performance easier as you scale the output goal and component sizes. And that is with the standard design...i'm not familiar with what folks try, but would guess you can do active rotor, I'll call it brushed induction, also if you were to try an even more complicated control regime where rotor magnetic field and induced winding voltages and currents could then get tinkered with by brushed hookups too them. Just doesn't seem settled what the overall best approach is.

But generally my understanding still is that an IPM design is harder to scale in performance without bigger compromises than induction. You have these spinning magnets that are creating a feedback and it generally things are sorta set and such in the inverter/controller based on those magnets and overall design and target output and you scale size losses increase, but with induction you can spend design time on the smart inverter to pull more performance/efficiency out as there are more control levers like the b-field since you don't have some static perm magnet field you are bound by.

BTW, I am structure person by trade. Closest we get to anything like this is modal analysis to ensure stuff doesn't shake off or apart. Magnetic field stuff is almost voodoo to me when it's static as it goes into this modal type thing you are dealing with in spinning motor and all the interaction and timing of it all...I really can't wrap my head around it and would have to design and test some different motor designs and tinker with these control approaches some to really have a handle on what would really work as an engineer. Even vibration modal stuff in aerospace that I am around we tend to just put stuff on a shaker table and see what happens if it's not really simple bracket holding something and something more like an electrical box it holds with all kinds of complicated geometry in connectors and wires and stuff like soldier.
 

Pushrods&Capacitors

Well-Known Member
First Name
Brian
Joined
Jun 24, 2021
Messages
624
Reaction score
1,253
Location
Round Rock, TX
Vehicles
‘21 4X, ‘14 SS Sedan tuned, ‘17 WRX tuned
Occupation
Analyst
Country flag
Dude. Nice!

Ok so can you educate me here? RWD unit looks just like it "should" for high torque extended constant power to near max. As I understand it, compared to higher power, lower torque (and usually smaller) units, acceleration curves should cross at some equivalent speed with the higher power units demonstrating increased acceleration with increasing RPMs. I also am under the impression that a lower torque, higher power unit will typically hit the equivalent speed at a shorter distance. So in my mind all of this would make sense if Ford is using higher torque extended constant power to hit the same 3.5 to 60 in a heavier vehicle compared to the model Y, with lower trap speeds and less acceleration after 60.

BUT...MYP and GTPE have essentially the same torque figures, GTPE has a HIGHER power rating, and people seem to be getting better acceleration after 60 if they don't start from 0--none of which makes sense unless there is some software interference. Correct? Are we missing something that would provide a simpler explanation?
No, it’s being manipulated. That’s it. You get Warps 1-4, 5-9 are currently being evaluated for safety.
 

Pushrods&Capacitors

Well-Known Member
First Name
Brian
Joined
Jun 24, 2021
Messages
624
Reaction score
1,253
Location
Round Rock, TX
Vehicles
‘21 4X, ‘14 SS Sedan tuned, ‘17 WRX tuned
Occupation
Analyst
Country flag
Well like I said I don't design motors or sparky control systems for them, and don't have tons of time to devote to understanding all the ins and outs of the different control regimes you are forced into with the two different motor designs. But Wally was was into this stuff and seemingly is part of his expertise. Not going to try and catch upto Wally after I heard his take years ago...just took it too heart.

Not that he is right or anything...but it generally sounds like the b-field adjustability which is really what I was trying to verbalize without really knowing all the terms for these designs, is what gives you tools to increase performance easier as you scale the output goal and component sizes. And that is with the standard design...i'm not familiar with what folks try, but would guess you can do active rotor, I'll call it brushed induction, also if you were to try an even more complicated control regime where rotor magnetic field and induced winding voltages and currents could then get tinkered with by brushed hookups too them. Just doesn't seem settled what the overall best approach is.

But generally my understanding still is that an IPM design is harder to scale in performance without bigger compromises than induction. You have these spinning magnets that are creating a feedback and it generally things are sorta set and such in the inverter/controller based on those magnets and overall design and target output and you scale size losses increase, but with induction you can spend design time on the smart inverter to pull more performance/efficiency out as there are more control levers like the b-field since you don't have some static perm magnet field you are bound by.

BTW, I am structure person by trade. Closest we get to anything like this is modal analysis to ensure stuff doesn't shake off or apart. Magnetic field stuff is almost voodoo to me when it's static as it goes into this modal type thing you are dealing with in spinning motor and all the interaction and timing of it all...I really can't wrap my head around it and would have to design and test some different motor designs and tinker with these control approaches some to really have a handle on what would really work as an engineer. Even vibration modal stuff in aerospace that I am around we tend to just put stuff on a shaker table and see what happens if it's not really simple bracket holding something and something more like an electrical box it holds with all kinds of complicated geometry in connectors and wires and stuff like soldier.
😱😱😱
 
Advertisement

 
Advertisement
Top