PERFORMANCE TUNING ANYONE?

[lotusman]

Is anyone tuning these cars? This is my first EV car, and I've tuned every ice car I've had.

Maybe there are torque limiters or other software changes that can make the car peppy?

Just curious.....I assume there isn't enough of a market for a tuner to hack the ecu software to make it worthwhile, but I thought I;d ask..

 

[jmueller065]

First of all:
The car is pretty peppy all by itself; something about 100% torque available at any RPM.

Second of all: because of the SSN issues I wouldn't want to put ANY custom code into any module in this car until that is 100% fixed!

 

[az erik]

First of all:
The car is pretty peppy all by itself; something about 100% torque available at any RPM.

Second of all: because of the SSN issues I wouldn't want to put ANY custom code into any module in this car until that is 100% fixed!

100% of less than 150ft/lbs of torque is actually not much when you're used to tuning ICE cars. My truck was a little over 1100 ft/tq and a touch under 650hp, the step down to the FFE was to say, a bit of a change.

On your second point I agree 110%%.

I'll put it into another electric perspective. R/C cars. You get a R/C car with a motor and speed control and it's set up for a battery. Sometimes 2 batteries. You decide to up the voltage by messing with something in the ESC. Your RC runs like a bat out of hell for 4 minutes and then bursts into flames. You are safe, but your car is toast. Now the FFE isn't much different. The motor was matched for the battery and most other things in the car were as well with a little head room. But from the sounds of the SSN it's VERY little head room. Realize you don't have any real monitoring of the motor or battery. And if either is pushed too hard for too long smoke is sure to follow. There isn't pinging or a wideband that will save you or at least let you know you've gone too far. Litterally IF these or any electric car (Tesla Roadster for example) are to be tweaked expect to hear about several of them going up in smoke first. Most every ICE tuner I ever worked with toasted several motors in their life before figuring it out. Also keep in mind ANY electrical/fire is grounds for total loss on a car.

 

[lotusman]

First of all:
"The car is pretty peppy all by itself; something about 100% torque available at any RPM."

I wouldn't consider it peppy, I guess its relative to what you're used to. V10 audi S6, highly tuned lotus v8 twin turbo, tuned mark 6 vw gti, these are the FFEs stable mates.

I appreciate the challenges and difficulties, I didn't know if there were torque limiters in place at lower speeds (for example to control wheel spin, I am putting stickier tires on, so have more traction to work with).

 

[WattsUp]

First of all:
"The car is pretty peppy all by itself; something about 100% torque available at any RPM."

I wouldn't consider it peppy, I guess its relative to what you're used to. V10 audi S6, highly tuned lotus v8 twin turbo, tuned mark 6 vw gti, these are the FFEs stable mates.

Granted, the FFE is not a sports car, but compared to "most" other normal cars (as opposed to your euro-garage), it's pretty peppy, and torqey. It's fun to "bump" my passenger's heads on their headrest while already doing 45 mph, or rocket up a hill like an amusement ride. They usually say, "whoa.. my car doesn't do that".

 

[jmueller065]

I guess its relative to what you're used to. V10 audi S6, highly tuned lotus v8 twin turbo, tuned mark 6 vw gti, these are the FFEs stable mates.

I also have a V-10 in my stable of vehicles. It isn't as fast as the S6, nor even as fast as the FFE. At over 8000lbs it isn't going to be; I've even customized it with a custom calibration to get more mpg and hp out of it (dropped the 0-60 time down by a full second!). As such it does a darn fine job pulling our camper around (with the two combined we are something like 15k lbs+ going down the road sipping fuel at a leisurely rate of 8mpg)!
(yeah its an F-350)

 

[unplugged]

Maybe there are torque limiters or other software changes that can make the car peppy?

I would like to see the software mapping of the initial rollout changed. It has been discussed that there is an artificial and limited feel of the initial acceleration from stop. When you floor it from a light, the full torque doesn't come on until about 20 yards.

The real problem is that, like you mentioned, with such limited sales (less than 2500) of the FFE, I don't know if anyone will bother mapping the module to change the FFE characteristics.

 

[davideos]

When you floor it from a light, the full torque doesn't come on until about 20 yards.

I think I've noticed this as well. I think the reason could be an issue of traction. Although I too would like some more power at the starting line, it may become too easy for the front tires to spin....as it is, my front tires definitely wear faster than the rear.

 

[WattsUp]

When you floor it from a light, the full torque doesn't come on until about 20 yards.

I think I've noticed this as well. I think the reason could be an issue of traction. Although I too would like some more power at the starting line, it may become too easy for the front tires to spin....as it is, my front tires definitely wear faster than the rear.

Yes, flooring it from stopped is limited to be a bit "soft". I get the impression this is purposely done to prevent the thing from spinning the wheels.

But, what I find... if you tap the accelerator to start rolling just a bit, and then depress it further a split second later, you should find more torque than otherwise. At least this is my impression. I think this pattern somewhat defeats the built-in limiting. You have to get a feel for it.

Someone else also suggested that L may have a slightly stronger "torque curve" (with emphasis on slightly). If it does, it is very hard to tell. Personally, I'm not sure... but I'm not yet totally convinced it doesn't.

 

[jmueller065]

The car is supposed to have both traction control and ABS.

My guess is that the extremely hard tires cause the traction control to back way off. I wonder if it would be a bit more zippy with more sticky tires.

 

[az erik]

I don't think it has an active traction control, more possibly passive (via the infamous rear Ford brakes) or just lack of a power band. reason being I can actually get the tire (yay 1!) to spin for about 1/2 second before it feels like the torque curve just craps out rather than an active traction control doing anything. My IS350 would pulse the power and ding like crazy when the traction control kicked in. The FFE feels to have just enough power to flub out after 1/2 second to make it seem like there is traction control.

Anyone drive the FFE in snow/ice want to chime in?

 

[jmueller065]

before it feels like the torque curve just craps out rather than an active traction control doing anything.

I think that *IS* the traction control. It is an electric motor--there is no torque curve. The wheel speed sensors detect the front wheels starting to spin and the motor controller backs off on the current to the motor. That implementation is sooo much easier when everything is electronic--no need to back off a throttle, reduce gas flow, etc. just tell the motor controller to slow down...
I doubt that it would use the brakes to grab the wheels to slow it down (for one thing that isn't very efficient).

 

[az erik]

It is an electric motor--there is no torque curve.

Actually yes there is a torque curve. There has to be or "power" could not increase.

If this motor only had 1 RPM what you're saying would be true. But it's a variable speed, thus variable torque motor. Otherwise all speed and power would be handled through a CVT transmission and not a single gear transmission. It is what I would refer to as torque crap out. It's there, right off the line, all of it, but it is not a all off the torque all of the time as commonly referred to.

The graph above shows a torque/speed curve of a typical D.C. motor. Note that torque is inversely proportioal to the speed of the output shaft. In other words, there is a tradeoff between how much torque a motor delivers, and how fast the output shaft spins. Motor characteristics are frequently given as two points on this graph:
The stall torque,[Ts], represents the point on the graph at which the torque is a maximum, but the shaft is not rotating.
The no load speed,[Wn], is the maximum output speed of the motor (when no torque is applied to the output shaft).
The linear model of a D.C. motor torque/speed curve is a very good approximation. The torque/speed curves shown below are actual curves for the green maxon motor (pictured at right) used by students in 2.007. One is a plot of empirical data, and the other was plotted mechanically using a device developed at MIT. Note that the characteristic torque/speed curve for this motor is quite linear.

This is generally true as long as the curve represents the direct output of the motor, or a simple gear reduced output. If the specifications are given as two points, it is safe to assume a linear curve.


Also note that the "100% torque available at any speed" can only be 100% available torque AT that speed. Note how fast the torque curve drops by RPM. I work on 4 pole brushless motors in my spare time. Torque to speed drop is about 60% torque loss per 10% rotational speed. What the motor lacks after 1000 rpm it makes up for in rotational speed at 6000 rpm.

 

[jmueller065]

Actually I think the motor is an A/C synchronous motor...not DC. (Which is actually worse because those have a stall torque.)

Here is some pretty cut-away pictures of it:
http://www.engadget.com/2011/01/11/ford-focus-electric-motor-extracted-split-asunder-coppery-guts/

If it was DC I'd expect the windings on the rotor not the stator.

It just makes so much more sense to me that it would be A/C synchronous:
- The speed is controlled by the frequency of the A/C (sort of: its the speed of the rotating magnetic field)
- No brushes
- Reversing the car is as simple as rotating the field the other way (reverse phase)
- Regen is also simple: the field rotates slower than the RPM of the motor
- Would use a constant voltage instead of varying the voltage for different speeds.

 

[az erik]

Actually I think the motor is an A/C synchronous motor...not DC. (Which is actually worse because those have a stall torque.)

Here is some pretty cut-away pictures of it:
http://www.engadget.com/2011/01/11/ford-focus-electric-motor-extracted-split-asunder-coppery-guts/

If it was DC I'd expect the windings on the rotor not the stator.

You're right it's a AC motor. Those actually do provide 100% torque at full speed. They deliver 100%+ from break torque and pull up torque, which makes the "100% torque" true. Which is better than 300% torque off the line.

Reason I got all wrapped up in DC is the EMW and a few others conversion kits I've been looking at use DC/DC. Makes me wonder just how much AC voltage is coming out of this battery. I thought I saw the battery at 480 volts or so.

 

[jeffand]

Stickier tires should give a slight improvement in acceration, but at the cost of higher rolling resistance.
This will reduce the vehicle driving range. Taking weight out of the trunk will help. A good place to start is the cargo organizer.

 

[davideos]

I know there is a big bulky thing in the trunk that takes up a bunch of space...maybe take that out.
Not sure the organizer is going to make much of a difference...but I have thought how much better if the FFE could be if it were 18" shorter as a 2 seater coupe and some of the battery weight over the front tires.

 

[hcsharp]

I wouldn't consider it peppy, I guess its relative to what you're used to. V10 audi S6, highly tuned lotus v8 twin turbo, tuned mark 6 vw gti, these are the FFEs stable mates.

I appreciate the challenges and difficulties, I didn't know if there were torque limiters in place at lower speeds (for example to control wheel spin, I am putting stickier tires on, so have more traction to work with).

Hey lotusman, I understand where you're coming from. You need a Tesla Roadster. You can get it with an adjustable suspension (from Tesla or aftermarket) that allows you to make some significant handling improvements. You can also do more with the traction control, which is much better than the FFE to start with. It will probably out-accelerate your lotus 0-60 and definitely 0-40. And unlike your lotus and S6, it won't wake up your neighbors doing it LOL. Oh, and it will be vastly cheaper to operate than your stablemates.

When I first drove the FFE, my first reaction was "Why doesn't it have any power?"
When my wife drove it for the first time, she said "Wow, It has lots of power"
All depends on where you're coming from. The Ford salesman reminded me that it has more power than the gas Focus.

Torque limiting is not done the same way it's done on an ICE vehicle. Everything is extremely tightly integrated in the FFE and the inverter is one of the limiting components. The firmware is so complex that you would go insane trying to reverse engineer it. I'd love to see what happens with lower profile stickier tires (other than reducing your range, which they will). Let us know when you try it!

 

[hcsharp]

A couple more ideas. Drive the car hard for a few minutes to make the battery as warm as possible. Then top it up on a 30A charging station so the battery doesn't have much chance to get cooled down again. A warm battery performs a little better. Always drive in L. It has exactly the same acceleration but more regen on the accelerator so it feels more responsive (and it is). And the last idea might be to let some air out of the tires. They're low rolling resistance and hard.

I have no plans to try any of these things. It's really the wrong car if you want a sports car.

 

[jloucks]

Wow! Tons of good info in this thread. I learned a lot. Thanks!

...that's all I got...