# Heel toe in an EV?



## GuySmily (May 11, 2012)

Does anyone (who still has a clutch) heel toe in their EV? Would the electric motor spin itself to oblivion with even a slight throttle blip?

I'm just getting started reading the Soliton manual, but I read that the throttle is ignored while braking (unless you double gas). Do you guys just let the clutch (or synchros) drag the motor up to speed? Do you not even shift until after the corner? Or does the torque curve of the electric motor mean that you don't even have to bother?

I grew up doing heel toe, and seeing people drag up the motor with the clutch bugs the **** out of me (especially when they ask to drive my car!).

I was trying to think about how you could program it into the controller, but it just seems like a nightmare. You'd need to know clutch position (I don't think the existing sensors for all the way up/down would cut it), gear ratios (or a programmed % to raise the RPMs by), and possibly even gear selection (maybe not - you could assume that brake + short throttle blip means to take the RPMs up 1 gear's worth).

For those who don't know what heel-toe is:
http://www.youtube.com/watch?v=U4MS5pNGbOU&feature=related


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## Duncan (Dec 8, 2008)

Hi Guy

Your motor is going to react FAST - very little inertia and lots of torque - I think the foot pedal would be too coarse to control it accurately enough - how about a little switch on the gear nob - you could trim it to feed a controlled amount of torque

My controller (OpenRevolt) uses 5Kohm = 100% - a momentary burst of say 5% 250ohms might be just what you want

Be very careful experimenting!


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## SandRailEV (May 11, 2012)

What does heel toe a clutch mean? I have been driving standards for 40 years and never heard the term....


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## piotrsko (Dec 9, 2007)

well: you are dealing with a soliton. If the rpm sense is installed, and set, your motor shouldn't over-rev except for perhaps a full pedal mash in neutral. Even then I doubt if the motor will respond that fast that the Sol can't control it. My over speed is set 1000 rpm below the max of the motor. YMMV. Overspeed on downshift in gear will be your fault, the Sol won't help there.

you can change coarseness of the throttle by changing the resistance curve to algorithmic or audio taper (which loads the voltage towards one end) and adjust the center point. I'm leery of the failure points of another external voltage source.

with a very light aluminum flywheel, you aren't going to have a lot of mass to spin up or down. I have found that up shifts take a bit of waiting, but downshifts are just a blip. I'm working on a bicycle brake for the front pulley for upshift without the clutch. Most of the time I just allow the trans to deal with rpm differences, but then again I'm not expecting this vehicle to go 100,000 miles. 

With the clutch, all this is generally a non event, just hit the clutch, jab the throttle, move the lever, release clutch, back on throttle, done. Half the time, I don't blip the throttle.

BTW: I'm in gear Before the corner, an old habit from the ICE days. I also don't use all the gears anymore, just 2,3,4. Could probably skip 3 on the flats, which I don't have. You'll also need better brakes, the motor doesn't help on decel.


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## GuySmily (May 11, 2012)

Duncan said:


> Hi Guy
> 
> Your motor is going to react FAST - very little inertia and lots of torque - I think the foot pedal would be too coarse to control it accurately enough - how about a little switch on the gear nob - you could trim it to feed a controlled amount of torque
> 
> ...


Finished reading the Soliton manual. It'll probably be years before I get to drive ab EV, but hopefully it won't be too impossible to rev match.

A little switch/button just takes all the fun out of it =p Actually, I can't imagine trying to blip the throttle and shift with the same hand.




SandRailEV said:


> What does heel toe a clutch mean? I have been driving standards for 40 years and never heard the term....


See video at end of my first post. It allows you to downshift while slowing down, that way you're at the right rpm/gear when you need to get going again.

This is a great video showing Ayrton Senna (famous F1 driver) using heel toe. His feet move so slowly/smoothly/gracefully.
http://www.youtube.com/watch?v=8By2AEsGAhU&feature=related


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## GuySmily (May 11, 2012)

piotrsko said:


> well: you are dealing with a soliton. If the rpm sense is installed, and set, your motor shouldn't over-rev except for perhaps a full pedal mash in neutral. Even then I doubt if the motor will respond that fast that the Sol can't control it. My over speed is set 1000 rpm below the max of the motor. YMMV.
> 
> you can change coarseness of the throttle by changing the resistance curve to algorithmic or audio taper (which loads the voltage towards one end) and adjust the center point. I'm leery of the failure points of another external voltage source.
> 
> ...


I did like the option of changing the middle point and ramp up, so long as it doesn't require major sacrifice of normal driving feel in exchange for throttle blip.

If you can't even feel the electric motor being dragged up to speed on a downshift, then maybe this isn't even an issue. It must be pretty easy to spin that motor up considering you can totally forego the clutch and make the synchros do the work.


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## SandRailEV (May 11, 2012)

GuySmily said:


> Finished reading the Soliton manual. It'll probably be years before I get to drive ab EV, but hopefully it won't be too impossible to rev match.
> 
> A little switch/button just takes all the fun out of it =p Actually, I can't imagine trying to blip the throttle and shift with the same hand.
> 
> ...


 
Ok, now I understand... Yes, this has always been standard practice for my driving style but I always called it "syncronizing the clutch", never heard it called "heel toe" shifting....


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## SandRailEV (May 11, 2012)

GuySmily said:


> I did like the option of changing the middle point and ramp up, so long as it doesn't require major sacrifice of normal driving feel in exchange for throttle blip.
> 
> If you can't even feel the electric motor being dragged up to speed on a downshift, then maybe this isn't even an issue. It must be pretty easy to spin that motor up considering you can totally forego the clutch and make the synchros do the work.


 
Interesting thread here as I have been thinking about this challenge as I design my system. Now keep in mind, I haven't even started on my conversion just yet, I am only in the planning stage. But, here's a config I have been invisioning. Given a 3-phase motor with IGBT controller, no clutch, program the regen based on throttle position and RPM, program regen to respond like a normal ICE downtorque. Use the old clutch pedal linked to a switch to signal the controller the pedal has been pushed in, the controller cancels regen and the motor freewheels, when you shift, the syncros bring the motor to proper speed. Let clutch out and you it should "feel" similar to a real clutch engaging. Sound do-able??


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## GuySmily (May 11, 2012)

SandRailEV said:


> Ok, now I understand... Yes, this has always been standard practice for my driving style but I always called it "syncronizing the clutch", never heard it called "heel toe" shifting....


The first time I ever saw it was in a cartoon. I had only started learning how to drive a stick, and I couldn't for the life of me figure out why you would EVER need to press all 3 pedals at the same time.

I'm not trying to turn this into a youtube thread or anything, but Nissan's "synchrorev match" in the 370z is almost freaky to watch. The way the rpms hold in EXACTLY the right spot is just weird to see.
http://www.youtube.com/watch?feature=endscreen&NR=1&v=27gW9ZS0rkI



SandRailEV said:


> Interesting thread here as I have been thinking about this challenge as I design my system. Now keep in mind, I haven't even started on my conversion just yet, I am only in the planning stage. But, here's a config I have been invisioning. Given a 3-phase motor with IGBT controller, no clutch, program the regen based on throttle position and RPM, program regen to respond like a normal ICE downtorque. Use the old clutch pedal linked to a switch to signal the controller the pedal has been pushed in, the controller cancels regen and the motor freewheels, when you shift, the syncros bring the motor to proper speed. Let clutch out and you it should "feel" similar to a real clutch engaging. Sound do-able??


Would probably need to put rules together similar to deceleration fuel cut in a regular ICE. Looking for the criteria now...


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## SandRailEV (May 11, 2012)

SandRailEV said:


> Interesting thread here as I have been thinking about this challenge as I design my system. Now keep in mind, I haven't even started on my conversion just yet, I am only in the planning stage. But, here's a config I have been invisioning. Given a 3-phase motor with IGBT controller, no clutch, program the regen based on throttle position and RPM, program regen to respond like a normal ICE downtorque. Use the old clutch pedal linked to a switch to signal the controller the pedal has been pushed in, the controller cancels regen and the motor freewheels, when you shift, the syncros bring the motor to proper speed. Let clutch out and you it should "feel" similar to a real clutch engaging. Sound do-able??


 
Edit to add, this will be a little harsh on your syncros but a better more complicated way is to install a speed sensor on the transmission input shaft linked into the controller. Program the controller to match the motor speed to the input shaft speed when a switch closes. That switch could be a manual switch on your shifter or again, maybe a clutch pedal switch...


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## GuySmily (May 11, 2012)

SandRailEV said:


> Edit to add, this will be a little harsh on your syncros but a better more complicated way is to install a speed sensor on the transmission input shaft linked into the controller. Program the controller to match the motor speed to the input shaft speed when a switch closes. That switch could be a manual switch on your shifter or again, maybe a clutch pedal switch...


It does make sense to make the controller do it without the user even having to think about it. Only issue I see is that the controller doesn't know whether you're going up or down when you hit that clutch pedal, so it'd have to wait for you to blip the throttle (regardless of brake position) before attempting a revmatch.

Might be fun to draw a logic diagram for this.

edit: I have a bad habit of editing my posts all the time. Not always a problem, but it is when other people are also actively posting (or have email notifications on)


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## SandRailEV (May 11, 2012)

GuySmily said:


> The first time I ever saw it was in a cartoon. I had only started learning how to drive a stick, and I couldn't for the life of me figure out why you would EVER need to press all 3 pedals at the same time.
> 
> I'm not trying to turn this into a youtube thread or anything, but Nissan's "synchrorev match" in the 370z is almost freaky to watch. The way the rpms hold in EXACTLY the right spot is just weird to see.
> http://www.youtube.com/watch?feature=endscreen&NR=1&v=27gW9ZS0rkI
> ...


 
Looking at programming regen in several VFD controllers, it seems easy to write the algorythm you want... Just modify it using imperical testing. I don't think it would take too long to dial it in the way you like it.


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## piotrsko (Dec 9, 2007)

Most controllers with guts don't do regen yet. Way too erratic on overspeed except sep-ex. From what I see you DON'T need all this stuff, just harsh the syncros a bit, add a cooler, NBD. You WILL need massive brakes with forced cooling.


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## SandRailEV (May 11, 2012)

GuySmily said:


> It does make sense to make the controller do it without the user even having to think about it. Only issue I see is that the controller doesn't know whether you're going up or down when you hit that clutch pedal, so it'd have to wait for you to blip the throttle (regardless of brake position) before attempting a revmatch.
> 
> Might be fun to draw a logic diagram for this.
> 
> edit: I have a bad habit of editing my posts all the time. Not always a problem, but it is when other people are also actively posting (or have email notifications on)


 
Oh wait, I think I over thought that one... oops... Yes, without the clutch the input & motor shafts are the same anyway.... Well, the vector controlled shift would certainly work with a clutch...


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## SandRailEV (May 11, 2012)

piotrsko said:


> Most controllers with guts don't do regen yet. Way too erratic on overspeed except sep-ex. From what I see you DON'T need all this stuff, just harsh the syncros a bit, add a cooler, NBD. You WILL need massive brakes with forced cooling.


 
Huh, you lost me here,....

Most VFDs I have studied make regen simple....


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## piotrsko (Dec 9, 2007)

series DC motors are generally the rule so far. all the other stuff is way lower power output, say < 100 hp unless you want to talk about 10 grand for starters.


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## GuySmily (May 11, 2012)

Regen is the reason I wanted to go with an AC-50+Curtis instead of Netgain+EVNetics. But seeing Tesseract here on the boards makes me think I'd be better off supporting EVNetics (and I'd probably getting support back, lol).


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## SandRailEV (May 11, 2012)

piotrsko said:


> series DC motors are generally the rule so far. all the other stuff is way lower power output, say < 100 hp unless you want to talk about 10 grand for starters.


 
AC, DC, to each his own. I am sold on 3-phase because I work with them everyday... They are flexible and powerful and require little maintenance... They also offer very easy ways to accomplish regen as well as other algorythms... And, from what I have seen, you're right in that DC offers little in the way of regen...

As for cost, I think it's basically a wash. You can spend lots of money on either one depending on what you're looking for in the way of power, torque curve, simplicity, maintenance, etc.


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## piotrsko (Dec 9, 2007)

SandRailEV said:


> As for cost, I think it's basically a wash. You can spend lots of money on either one depending on what you're looking for in the way of power, torque curve, simplicity, maintenance, etc.


Don't know if it a wash but: amen to that^^^^


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## SandRailEV (May 11, 2012)

GuySmily said:


> Regen is the reason I wanted to go with an AC-50+Curtis instead of Netgain+EVNetics. But seeing Tesseract here on the boards makes me think I'd be better off supporting EVNetics (and I'd probably getting support back, lol).


 
Ok, so now I am confused. What is your current config? Motor type (AC/DC), do you have a clutch still? Does your controller support regen? If AC, do you have a vector sensor??

Maybe I missed all these things in your previous posts...


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## GuySmily (May 11, 2012)

Oh, I don't have anything built yet. Sorry for the confusion. Still only in planning phase. I started this post because I hadn't seen anything on the subject and nothing came up when searching.


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## SandRailEV (May 11, 2012)

GuySmily said:


> Oh, I don't have anything built yet. Sorry for the confusion. Still only in planning phase. I started this post because I hadn't seen anything on the subject and nothing came up when searching.


 
I see... I am pretty much in the same boat. I have the donor which is an old VW sand rail... It's stripped down and am still painting the frame and getting an approved windshield put in... I have all my welding done except that I haven't built the battery boxes yet so I will most likely attempt bolting them in. 

I do have all the ruinning gear purchased already; 4 wheel disk brakes, new bearings & seals, link pins, etc. I hope to be able to have a roller by the end of summer 2012... Next thing is the motor and I am at a crossroads decision. I will be using AC 3-phase but I am split between the AC-50 or an industrial motor. The AC-50 looks like a great motor for what I want & need. It has lots more torque than the original ICE and especially at low revs. And the Cuirtis controller looks like a nice easy way to get everything going quickly BUT, that controller only allows pack voltage up to 130 and I really would like to go up to about 170 or so. 

The reason is that the AC-50 synchronous speed is 3600 for 60 cycles. When the drive outputs beyond 60 cycles for higher speeds, the motor torque drops off. In order to maintain torque at higher frequencies and speed, the controller must also increase voltage, but you are limited to your pack voltage. The curtis controller stops increasing voltage output at 60 cycles and unless you hack into the controller with mods, that's where she stops...

So, I am deciding whether to go with the Curtis and be stuck with it's limitations or to go with an industrial VFD and tailor it to my needs... This would take some hardware mods such as building an external IGBT output stage and possibly a driver stage... Not having much hands on experience with VFDs, it's taking some hard study time to decide which way to go... Of course like most people, I am on a rather strict budget. 

Anyway, if you end up going the AC VFD route and you are planning to keep the clutch, I would think it would pay off to place a vector sensor on the transmission input shaft (assuming you are including a sensor on the motor shaft) and then programming the controller to match the motor speed to the input shaft speed during shifts. This likely would not only make the shifts smooth and fast, but it would also save wear on your syncros....

My current plan is to do away with the clutch...

But, keep us informed on your decisions....


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## dragonsgate (May 19, 2012)

The heal toe works with an ICE as demoed in the videos but I have missed how it applies to an EV. I just stick it in second gear and go. If I go to the next town 12 miles away I ease it into third for sixty mph and if I think nobodies around sometimes forth and hit seventy. As for down shift from fifth to second gear.. may the gods of scrap metal be with you. The only reason to down shift with an electric motor that I can see is because you have already slowed down below the speed it is electrically economical for the gear you are presently in. I run clutchless as many others do so when going through the many bends in the roads around here I use left foot for break and right for gas er I mean electric. Regen for braking is something that almost all DC owners dream of. That is why I have been looking into motors like the AC50.


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## SandRailEV (May 11, 2012)

dragonsgate said:


> The heal toe works with an ICE as demoed in the videos but I have missed how it applies to an EV. I just stick it in second gear and go. If I go to the next town 12 miles away I ease it into third for sixty mph and if I think nobodies around sometimes forth and hit seventy. As for down shift from fifth to second gear.. may the gods of scrap metal be with you. The only reason to down shift with an electric motor that I can see is because you have already slowed down below the speed it is electrically economical for the gear you are presently in. I run clutchless as many others do so when going through the many bends in the roads around here I use left foot for break and right for gas er I mean electric. Regen for braking is something that almost all DC owners dream of. That is why I have been looking into motors like the AC50.


 
What's your current config? also what is the donor car??


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## dragonsgate (May 19, 2012)

I have a post in conversions and builds under the title ac to dc switch. I probably should have put it under motors. I have pictures in the ev photo album. Type in Cliff’s 1984 electric fiat X19 and that should bring you to my pictures and info.


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## mizlplix (May 1, 2011)

My pardon to all who posted above.

Heel n toe is one method to match the lower gear set to the main output shaft. It does not know or care about the power used.

There is a timing/coordination difference between power tranes, even flywheel weights or rear axle gear ratios.

You, the driver, merely adapt to the combo. It Is a practice thing.

Yes, I heel n toe down shifted my Electrica, it required a much smaller throttle input...that's all. If you usually press 2" down on the accelerator in your pick up...you will wind up pressing 1/2" in your EV. 

This method is not based on holding the pedal down, merely a fast "blip".
Do not wait to hear the motor rev up like you are used to, by then it is way too fast.

One other method that worked in the Electrica was to de clutch, put in neutral, clutch out, lightly press the shifter in the lower gear and slowly press the accelerator. It will just drop into gear when the RPMs match, providing the trans allows it. Mine did.

Miz, (ex employee of the Bondurant Racing School)


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## dragonsgate (May 19, 2012)

I get what you are saying about the matching shaft speeds and I have used the method in shifting with toe to throttle heal to brake and clutching in slaloms etc. But I can’t figure using the brake in an EV for anything other than slowing down or stopping. As for double clutching…anyone who ever drove the early British cars to any degree has probably mastered the method of double clutch.


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## dragonsgate (May 19, 2012)

Miz, I see you are using an AC 50 in your build. I am trying to gather info on this setup. I would be interested in anything you might know about the AC 50. In order to sort of keep with this thread I will venture to say with an AC motor one would have a wider rpm range making for less need to shift gears. 
So as to not Hi-Jack this thread you can answer me in my post under ac to dc switch if you like.


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## mizlplix (May 1, 2011)

It is called Trail Braking. It involves carrying too much speed into corner entry and braking late. It is for chassis dynamics and works with any type of car.

Braking with the heel while the big toe is on the throttle and the left foot is doing the clutching is a racing technique. It allows you to dive deeper into the corner on entry phase. It transfers a ton of weight onto the front suspension forcing front tire compliance and makes the car rotate into the corner. 

When down shifting the toe blips the throttle while the rest of the foot is on the brake and the shift lever is in neutral matching gear speeds so when the clutch is let out, there is little or no rear wheel speed change. Rear wheel speed change during the corner means a shear to tire compliance causing the car to be loose and loss of control. 

Open wheel racers have the pedals closer togather and the big toe is on the brake while the small toes are on the throttle.

A good road racing driver is awesome to watch. They are so very smooth at it.

Miz


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## dladd (Jun 1, 2011)

I have a DC motor/controller combo (Warp9/Synkromotive) and still have my clutch/lightened flywheel. I heel/toe all the time, more out of habit than anything. In my car, I generally use either just third gear from 0-50, or 2-3-4 if I'm in a more sporting mood and want to shift. Which is most of the time. 

I simply didn't hook up the brake light input to my controller, so it does not cut off with the brake. It means obviously I need to be careful to not stall the motor when stopped, but I can brake/accel at the same time for downshifting or trail braking in corners.

It took maybe 10 shifts to get the feel for it, now it's nothing I ever think about. It takes a pretty intentional 'blip' of the pedal to spin the motor up enough, and I have overspeed protection in the controller just in case. It works fine.


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## dragonsgate (May 19, 2012)

Ok The little light bulb above my head is flickering. I can see how heel toe can work in an EV if you have a clutch. I imagine it can be better than an ICE seeing as how motors have a more responsive low end torque.Looked at dladd’s web page and I think he is serious about ev’s. It makes my car look stone age.


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## dladd (Jun 1, 2011)

dragonsgate said:


> Ok The little light bulb above my head is flickering. I can see how heel toe can work in an EV if you have a clutch. I imagine it can be better than an ICE seeing as how motors have a more responsive low end torque.Looked at dladd’s web page and I think he is serious about ev’s. It makes my car look stone age.


fwiw I'm an EV noobie, just bought my car last October and have about 3000 EV Miles. I love it and have fun working on it, but I'm no expert!


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