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Nashco UberDork
2/28/14 1:57 p.m.

I recently bought a 2014 Chevy Spark EV. I have been (im)patiently waiting to buy this car since GM started releasing specs on the powertrain, as the numbers were shaping up to be pretty good for a fun, sporty EV. I'm a big fan of hybrids and EVs in general, I like small cars, and I like trying new things...so I decided to get this EV hot hatch and see how it goes. From a very high level, this is the best performance value you can get from an electric car...power to weight to dollar ratio is the best on the market, seemingly targeting the GRM mindset. It's the quickest EV you can buy that is NOT a Tesla, and it's only $20,000 after the government tax credit so it's a great value (one of the cheapest EVs on the market).

I took delivery of the car last month (January 2014) and I've already started to tinker.

Some specifics about my Chevy Spark EV as delivered, according to GM:

  • Options include 2LT trim package and DC fast charge option (RPO code: CBT)
  • 2989 pound curb weight
  • 140 hp, 400 ft lbs
  • Single speed transmission with 3.17 planetary gearset
  • EPA battery range is 82 miles

I like to box myself in with some constraints for projects, so here's what I'm trying to accomplish:

  • Daily driven...the more I drive it, the more money I'm saving on fuel!
  • Competitive in already existing classes against similar gas powered cars without any special allowances
  • What I build can be easily duplicated, no engineering degree required!
  • Car must be able to haul 4 tires+wheels and tire changing equipment inside OR my huge dog on non-race days

The most obvious places to make a competitive EV are autocross and hill climbs. After reading the SCCA solo rule book a few times (SNORE!) and going to the Nationals in Lincoln last year, I decided STF seemed like the right place for it. Maybe it is, maybe it isn't, but you've got to start somewhere and that seemed like a fun class. Of course, I'll have to learn a heck of a lot by trying to petition and get it into the list of allowed cars in STF, but I guess that's part of the...um...fun?

If you assume that the Spark EV was allowed to participate in STF, these are some things that I could do that may (or may not!) make it more competitive than a stock Spark EV (in order of appearance in the rule book):

  • Replace driver and passenger seat (minimum weight of 25 lbs each, must attach in OE locations)
  • Add 2 point strut bar (between top of front struts)
  • Tires (duh!) - Class allows up to 225, 140+ treadwear (until 2015, then 200+)
  • Wheels - Class allows up to 7.5"
  • Dampers
  • ABS can be disabled
  • Anti-roll bars (likely add to the rear?)
  • Lowered ride height
  • Suspension bushings
  • More front camber from camber bolts or camber plates
  • More rear camber from axle shims
  • Lightweight 12V battery
  • Traction control can be disabled
  • Reprogrammed powertrain control module and/or piggyback controller
  • "Engine" shields for accoustic/cosmetic purposes only can be removed
  • "Engine" or transmission mount

In theory, those are the types of mods you're likely to see me attempt/consider for this build. Some are easier said than done, but that is the kind of stuff you'd expect to do if you're trying to be competitive in STF.

The local hill climb group basically follows SCCA rules and seems pretty open minded, so I expect it should be pretty straight forward to play with them too.

That seems like enough background info, I'm rambling. On to the fun stuff, actually building it instead of bench racing!


Nashco UberDork
2/28/14 1:57 p.m.

The first modification I've done is install a Megan Racing suspension so that I could lower it and have the ability to change springs and damping rates easily in the future. I knew I wanted to lower the car right out of the bat, but there aren't any lowering springs available for the Spark EV, so I was forced straight into a custom setup. I wanted to use some Koni double adjustables, but unfortunately the front strut bodies for the Spark are too small in diameter to accept a normal insert and I didn't want to get into a fabrication project that would be too hard for the typical person to duplicate.

Megan Racing makes a kit for the gas Spark that has single adjustable dampers, accepts common aftermarket spring sizes, is fully adjustable, and bolts in. Unfortunately, the EV doesn't share the exact same suspension as the gas Spark in the rear suspension, so the Megan Racing kit isn't directly compatible. I did some pretty simple modifications to make the kit work on my car, BUT I am working with Megan Racing to figure out what parts they make (for other applications) that I can mix and match with the gas Spark kit in order to make this a bolt-in. It has been a little difficult working with their tech support in California, who is working with their manufacturing people that are overseas.

With that said, I will not detail exactly what I had to do with the suspension yet. I don't want to put information out there that I know isn't the recommended path, I will put specifics out when I have a better proposed plan for others that may try to duplicate my setup. However, I can give you a teaser...this is what a Spark EV looks like about 2" lowered.

Stay tuned for specific details on the suspension install...it will likely be a month or three before I'm done, as Megan Racing hasn't been in a rush to help me solve this.

I did some tire and wheel mock ups at the same time, and it's not going to be easy fitting STF-compatible rubber into this thing. GM also hasn't made it easy on me as the front and rear wheels have different wheel width AND offset with surprisingly tight clearances from the factory, so wheel selection gets tricky. I bought a cheap set of worn out 205/50R15 BFG Rivals from a local crap can racer to try first, but even that will be a tight squeeze. I want to keep the stock wheels and tires together and get some lighter aftermarket wheels, so I'm still on the hunt for the right wheels.

One thing is for sure, this car is in dire need of better rubber than what it comes with stock. Even on clean, dry pavement you can't use full power to accelerate from a stop without the traction control going active.


BoxheadTim GRM+ Memberand PowerDork
2/28/14 2:19 p.m.

Cool project!

GameboyRMH GRM+ Memberand MegaDork
2/28/14 2:20 p.m.

Maybe 195/50/15 on 15x7? That's a good bit smaller than 205/50/15.

Although I'm running that size on a car that's not even 2500lb with me sitting in it and it feels like I could use more now.

4cylndrfury MegaDork
2/28/14 2:31 p.m.

Rear sway bars will make a pretty big difference I would imagine. Im not sure what the crossmember/control arm setup is under there, but most FWD cars Ive driven were loads better off the line controlling traction and wheel hop with urethane crossmember and arm bushings. Between stickier rubber, and a sway bar and some bushjings, Id bet youre probably going to make a huge dent in the acceleration department.

Also, I have no idea what a single speed planetary transaxle is like - any way to buy/fabricate a limited-slip component?

Keep us informed, this does seem like a fun project!

Nashco UberDork
2/28/14 2:38 p.m.

I may end up with some 195/45 or 195/50 tires, only time will tell. With the weight of this car, obviously bigger would be better, but even with rolled fender lips from the factory, there's just not much clearance.

STF doesn't allow differentials that aren't available from the factory, so no need to do any further investigation on that front. That's the nice thing about picking a class to force my options for a while!


bgkast GRM+ Memberand Dork
2/28/14 3:03 p.m.

I'll be watching. I want an electric...c'mon deprecation!

Ransom GRM+ Memberand PowerDork
2/28/14 4:45 p.m.

Awesome! Looking forward to updates...

It's too bad there's no handy way to modularize the batteries for autocross. It would be awesome if the normal weight penalty of an electric could be mitigated by removing unneeded range for a 60-second run. Though I'm sure that would fall outside STF anyhow...

Vigo PowerDork
3/2/14 12:26 a.m.

Tire options are extremely limited in 195/45/15, so i would avoid it. I can only think of 3 off the top of my head and none of them are serious autox tires in the slightest. 195/50 has a much larger selection.

Whats the weight distribution like on that thing?

Nashco UberDork
3/2/14 2:36 a.m.

When it comes to fitting the best tires you can with the package space dealt, I've got a fair bit of experience with it! Trust me, I won't be using a strange tire and size if there are better alternatives.

GM publishes the factory specs at a 52 front / 48 rear ratio in stock trim. I haven't weighed it yet.


camaroz1985 Reader
3/3/14 10:47 a.m.

Looks like an awesome project and idea. I'll be following along closely. After driving my boss's Tesla Model S, I am hooked on the idea of an electric race car.

Petrolburner New Reader
3/5/14 7:42 p.m.

Very cool! I will be coming to Portland for autocross races whenever possible, hope to see you there. I'll be at the Starting Line school at PIR on the 15th btw.

Flight Service
Flight Service MegaDork
3/5/14 8:20 p.m.

Nashco UberDork
3/13/14 5:04 p.m.

Not very racy, but I put some GM floormats in and documented how that went in this thread:

GM all weather floormats in the Spark EV (Part 95259816)


Nitroracer SuperDork
3/13/14 7:45 p.m.

I just noticed you own both a Leaf and a Spark. Interesting pair, but are they comparable at all?

I'm looking forward to seeing what you can do with this car. Electric has my interest but its not something I can afford to buy into yet.

Nashco UberDork
3/14/14 5:16 p.m.
Nitroracer wrote: I just noticed you own both a Leaf and a Spark. Interesting pair, but are they comparable at all?

That would be like comparing a Chevy Sonic RS and a Nissan Altima S. They're not at all targeting the same market IMO. Sure, the Leaf and Spark are both electric and have similar fuel economy and propulsion methods, like a Sonic and Altima are gas and get similar economy, but they're not the same cars at all. Because most people consider the EV part to be pretty polarizing, they would lump the Spark EV and Leaf together in the EV category...however, I would argue they have as much different from each other as they do in common. My wife would agree, the Leaf and Spark EV are different tools for different jobs.


Javelin GRM+ Memberand MegaDork
3/14/14 10:00 p.m.


Are you bringing the Spark out to any ORPCA autocrosses this season?

Nashco UberDork
3/15/14 12:26 a.m.

I intend to go to as many as I can. I've never been to any PCA events, but I like that they're regular and only a few miles away.


SVreX MegaDork
3/15/14 5:27 p.m.

Is there any requirement to have the full factory battery packs on board?

How else could you get 356 volts with, perhaps 10 kwh?

You shouldn't need 21.4 kwh to get you through a track day.

That 560lb battery pack has got to be on the hit list if there is any way possible.

Nashco UberDork
3/15/14 5:54 p.m.

I put a list of allowed modifications in the first post. Traction batteries can't be modified. Even if they could, that's way beyond the scope of this project, as it isn't something the average Joe could duplicate.


Hasbro Dork
3/15/14 6:12 p.m.

Looks like a neat project. How does the suspension feel with the 2" drop? I'm very curious as to what tread you will eventually stuff in there. That's a lot of weight for 195s/205s, as you know. Have fun!

Nashco UberDork
3/27/14 6:55 p.m.
Hasbro wrote: Looks like a neat project. How does the suspension feel with the 2" drop?

It feels poor at this point, like I tossed a cheap Chinese coilover set on it and slammed it! It desperately needs different springs in the rear, I haven't bothered to change the dampers from full stiff yet to see how that helps, and it should probably get raised an inch to allow for a bit more travel in the rear. Of course, the plan is to address those issues in the future! I'm still going back and forth with Megan Racing to see if I can get some different parts from them for the rear before I go tearing it apart (yet) again. This suspension will obviously take a while to dial in, no easy bolt-ons at this point.


Nashco UberDork
3/27/14 6:55 p.m.

I attended the first local SCCA autocross of the season last week. The primary goal was to get a feel for the local SCCA group and shake some cobwebs loose for me, since it's been a very long time since I autocrossed with the SCCA. I was also hoping to begin the learning curve for how the traction control, stability control, and torque delivery played together with inadequate traction.

I put a bunch of tire pressure into the stock tires, removed the charger/flat tire kit, and put the floormats on the passenger floor area. I used blue tape for the numbers and picked up some plastic to protect the front end paint from cones. That was the extent of my "prep" as the lowered suspension hasn't even had a proper alignment yet and I'm running horrible stock tires.

A couple of guys made fun of my plastic front end protection, referring to it as "cone repellent" since I didn't hit any cones. Yes, it's true, I'm a little scared to damage the car still. Heck, I don't even have license plates on it yet! Anyway, for those that are interested I used this stuff to cover the front end. It's plastic with a light adhesive backing used to protect carpets during construction work. Maybe this is super common to do, but I've never seen it so I thought I'd share. I picked this stuff up at Lowe's, it's really cheap.

After taking my turn working the course, I queued up in line. I met another GRMer, a burrito enthusiast just hanging out for the day. I tried my first run with the stability control and traction control turned off to see how things went; as expected, the stability control almost immediately re-enables itself at speed. The first run was ugly, but they always are. More than one person commented that they were confused why my car was so quiet, then after they realized it was electric they were surprised at how quick it was. I chilled out just enough to think to take a picture as some ominous clouds rolled in.

Unfortunately, rain came with the clouds. Rain in March in Portland doesn't come as a surprise, of course, but a bummer nonetheless.

The good thing is that this really highlighted the traction and stability control system functions, making it possible for me to keep track of cones AND the car at the same time. Remember, I'm no pro at this! I tried a couple of configurations with traction control on and off. The car is severely limiting power after the stability control has been active and traction control is on. The good thing is that in nasty weather, the stability control really helped to force the car in the direction I was intending to go rather than where it would go if it were turned off. The bad news is that for what seemed like an eternity (.5-1 seconds) I had little to no power until the system had stabilized on a straight path. In autocross, straight paths don't come around often, and half a second is a really long time to go without power, so if I'm really crossed up this is a major problem. The other tricky thing is that I haven't got used to what the system will allow and won't allow, and I expect this will change drastically with stickier tires, so I'm kind of at a loss. I tried the rain with traction control off to see how this affected stability control, but it was so difficult to keep the tires from spinning with this car in the rain that it wasn't worth trying a second time.

Oh, and for record keeping sake, my first run was my fastest (because it was my only dry run) and I ran the "Time Only" class.

So, going forward, I definitely need to figure out how to fully disable/enable the traction and stability control with the flip of a switch...mostly to have a consistent car (with the systems turned off) that won't mask my bad driving while I try to figure out how to optimize the car and my driving. Secondly, I need a LOT more seat time to figure out the car and get acclimated to autocrossing.

This weekend I'm focusing on the second point, seat time. I've signed up for a Porsche Club of America Driver's clinic on Saturday morning and autocrosses on Saturday afternoon and Sunday morning. I'm also signed up for the SCCA solo driver school coming up next month. Hopefully this seat time helps me at least get into the swing of things around the cones so I'm less frantic trying to follow the course and can give more mental focus to the car and what needs to be done to make it work better. Now I have a better understanding of why dataloggers and video systems are so popular! I might even rig up my GoPro so I can watch video of my habits and the car responses from the next autocross if I get time.


Nashco UberDork
3/27/14 7:05 p.m.

Oh yeah, I forgot to mention energy consumption. Since the onboard computer has an extremely accurate energy consumption measurement and I'm in new territory here, I thought I'd keep track for those that are curious.

According to the instrument cluster, I used 1.2 mi/kWh over 3.29 miles for the event itself, which included four runs. That means I'd have enough energy on board with a full charge to do approximately 60 runs on this particular day. I don't think I'll have much to worry about for autocrosses.


Ransom GRM+ Memberand PowerDork
3/27/14 7:16 p.m.

Awesome! There may be a lot to figure out, but you know a lot more than you did Friday... Here's hoping it's not catastrophically difficult to get some control over the stability and traction controls...

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