The electrified Mustang Ford should have made… S550 Mach-E build project

[zackmd1]

The issue might have been exacerbated by my choice of S650 control arms instead of S550. On a normal car they are interchangeable but it appears that the casting is just different enough in the wrong places to make the issue worse. Passenger side with an S550 control arm is much closer to working. Other than the CV joint, I'm actually quite pleased with how a Mach E CV works in the S550 suspension.

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[zackmd1]

I think we have a solution. Control arm will still need to be notched to clear the CV boot but shortening the inner CV by 25mm worked. Just enough plunge distance for the most extreme control arm angle I could simulate (unrealistic in a street car, ball bearings which transfer rotational energy are still contained within the CV joint).

Also discovered that the Mach E runs asymmetric CV axles. The drivers side axle is significantly shorter than the passenger side. The passenger side CV axle however appears to be the perfect length for the S550 suspension. Might be able to get away with 2 passenger CV axles as long as the outer CV joint is the same as an S550. I will need to swap S550 outer CV joints for the correct spline to interface with the wheel hubs.

 

[zackmd1]

Difference in length between driver and passenger CV axle for the Mach E.

 

[zackmd1]

I’d say the S550 half shafts were designed for a bit more power…. Good thing is my cut down inner CV is identical in length to the OEM S550 inner CV. That should hopefully mean I’m good on plunge distance with the CV.

Going to try to combine these half shafts this weekend. Modified Mach E inner CV, passenger Mach E axle shaft, S550 outer CV.

 

[zackmd1]

Well as expected, I cannot use the Mach E haft shaft directly with the S550 outer CV... 3mm difference in diameter at the splines (s550 being larger....) So custom half shafts it is... Yay...

 

[zackmd1]

Fun little easter egg I found on the motor this evening.

 

[zackmd1]

Got the custom toe arm brackets from sendcutsend welded in. I intend to use adjustable toe arms instead of the factory alignment bolt. Now back to the CV axle issues...

 

[zackmd1]

CV joint cut down and features added back. Also made an adapter for the GT4 CV boot. Only CV boot that I have been able to find so far with this much thinner design. Hopefully this will allow me to avoid having to notch the control arms....

 

[zackmd1]

Also want to get everyones opinion on the path forward...

The deeper I get into this project, the more painfully obvious it is that the aftermarket support just isn't there yet for an EV build. Things that I would consider major requirements like fast charging, vehicle integration, reliability, etc... are SIGNIFICANT hurdles currently. Whether that's from a monetary standpoint or software development standpoint.

With the project morphing into a Mach E drivetrain, It got me thinking again about using the full electronics package from a salvaged Mach E for this project. The sticking point early on was that the Mach E battery simply doesn't fit well in the S550 chassis. Now that I have a better understanding of how the BMS works and how the battery was designed, I believe I can utilize the polestar battery modules with the Mach E BMS and get around this issue.

My current polestar batteries closely match the standard range battery configuration (96s3p LG Chem NCM cells). Ford uses E73a cells in the Mach E where as the polestar uses E66a. A slightly smaller capacity (~91% Mach E capacity) but otherwise identical cell. The BMS should have no issue with the E66a cells. The downside here is that it limits me to the RWD Standard Range or AWD Standard Range config of the Mach E which has around 270hp (wheel HP that is) and either 317tq or 428tq.

If I went with a donor SR AWD I would end up with a car comparable to a tuned EcoBoost in terms of power and weight. Not bad at all and would be pretty fun to drive with 600-700lbs less than is previous life as an SUV... 0-60 times should be in the high 4s with quarter mile times in the low 13s.

The more risky/expensive route would be to go for a Mach E GT and utilize VW ID4 modules. The GT only came with the extended range 98kwh pack. I haven't been able to find any indication that I can change the battery capacity in the BMS with tools like forscan so a significant difference in capacity would likely result in a lower SOH (State of Health) reported by the BMS. If this SOH drops below 70% (of original programmed capacity) I believe the BMS throws a DTC and a wrench light on the dash. So.... 12 ID4 modules would result in an 82kwh battery or about 82-83% extended range capacity. As the battery ages, this would obviously get worse tell where when the ID4 modules would be at 85% original capacity, SOH reported would be in the low 70s. Likely still fine but close.... In addition, weight and packaging becomes a concern again...

Sooo.... The question is do I go with a donor AWD SR or chase power figures and get a GT. With either route, I would be getting DC fast charging, ford pass app support, Tesla Supercharger access, and a more integrated and feature complete vehicle. Of course the DIY route is still on the table but none of the listed features above would likely be initially possible.

What's everyone's opinion?

 

[Mach VII]

You're going through a lot of effort, I would get what you want and go for the GT.

 

[zackmd1]

Axle mock-ups complete. Need to send them out now to get reproduced as one piece. Pictures represent CV angle at a 1" drop ride height.

 

[Sparky1337]

I want to say the SEMA F100 was just a transplant Mach e so it would depend on your plans for the car. Like on how much you could get an intact GT from copart vs a standard range.

 

[zackmd1]

Ok so been awhile since an update... Lot of life events occurred and some additional research on the legal side of this build. Unfortunately, not great news on the legal side so far. As it currently stands, I don't believe a late model vehicle would pass a Maryland safety inspection having been converted to an EV. Ironically, its due to the EV not having the original emissions equipment that the vin says it should have.

Haven't found an inspection station or inspector that was willing to give an answer on the subject. Even talked with the state police directly and while it wasn't an immediate no, they didn't give me an answer either. So with that, the project is going to be put on hold until I can straighten these questions out. No sense spending money on a project that ultimately might not be drivable in my home state... I'm confident that I can get a good answer eventually and during the pause period, it hopefully allows the aftermarket to mature a bit more on some areas like fast charging and more stable high density LFP battery modules. Quite a few "coming soon" options for fast charging.

In the meantime, I did end up acquiring another S550 originally as a parts car for this build but it was in better condition then expected. I'll be doing a "quick" build with that chassis to bring it back to life. I'll end up getting a few needed parts for this project and a lot of valuable info on seam seal locations, etc...

So the project is not dead! Just on hold tell I can get more info on the legal side... I'll have a separate build thread for the other S550 if you are interested In following along.

 

[WItoTX]

Montana plates solve many things. Keep going!

 

[zackmd1]

Montana plates solve many things. Keep going!

I wish!! The current regime here in Maryland is trying to crack down on out of state plates after they sent the titling and registration fees through the roof…

There is a pathway through the other S550 where I get it inspected with the Godzilla, have my fun with it, then convert to EV….

That should tell you everything you need to know about the MVA and Maryland. Blue state is pushing me to build a big block V8 because that would pass inspection but the environmentally friendly EV build won’t because no one wants to make the call.

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