Finally added the EV mod

I've been reluctant to add an EV switch. I haven't seen many (any?) folks with the mod come out and say with certainty, "It saves me fuel." Therefore I couldn't justify spending the money or the time.

But as time goes on I become increasingly aware of this remarkable car's subtle -- and sometimes baffling -- nuances. What moved me to finally consider an EV switch is frustration with the ICE running between a string of 4 stoplights, most of which are usually red, in the middle of my commute. They're not far enough into the commute for the car to be in S4 operation. They're too far apart to "pedal-feather" EV without inciting hostility behind me, but too close to hit 35 MPH to get the ICE to shut off.

(For the uninitiated, 5 distinct warmup stages -- labeled S1, S2, S3a, S3b, & S4 -- have been described. See this paper for more. Though there may be some question as to the exact temperature and time thresholds where stage transitions occur, the behaviors are unmistakable. To the point of this post, until the car reaches S4, it will not do an ICE-off glide unless the glide begins at a speed >34 MPH.)

As another example, on my morning commute I have a stop light, usually red, about 200 yards before I turn left into the office lot. Again, traffic is too heavy for pedal-feathering EV from the light into the lot. But even at the end of this short commute, the car often doesn't make it to S4. So after I give it the gas at the light, the ICE often stays on until I approach my parking space. I watched the ScanGauge one recent morning during this episode. Trip MPG went from 75.4 (at the light) to 74.3 in about 300 yards.

I considered the Coastal switch, as I described here. In the midst of that thread Hobbit made an offer to install a "home-grown" model for me at Hybridfest. Frankly I had been a bit intimidated by others' descriptions of installation; I'm somewhat "mechanically challenged." That's why I first leaned toward what others reported as an easy installation routine offered by the Coastal product. But Hobbit got me thinking: If the home-grown approach is simple enough, and if he has time and the willingness, to do it in the midst of all the activities and hoopla at Hybridfest, just maybe I could tackle it myself. So I began studying the approach with its variations described here and elsewhere.

I primarily used Evan Fusco's instructions, featured (with photos) on CalCars' web site. Thanks to that terrific writeup, installation was a breeze, other than one minor problem of my own creation. More on that in a minute.

I had previously disassembled the dash to install an integrated XM radio unit, so the prospect of removing a couple of vent panels and the lower glove box never bothered me. Harvesting the pin from the steering wheel was a snap. Evan's instructions suggested using a jeweler's screwdriver or paper clip to release the retainer clip on the ECU plug, but I found needle-nose pliers worked better. No problems soldering the wire to the pin. It was a tight fit to get the pin into the plug, but I got it. Needle-nose pliers helped there too. Rather than splicing the ground wire into an existing wire (I didn't feel quite that adventurous), I attached it to a bolt at a metal attachment point of some sort behind and toward the top of where the AC vent dash panel goes. After attaching the ground wire I tested the assembly by turning the car on and touching the wire ends together. I got the expected beep and no ICE activation.

From there, no problem using the coat hanger to snake the wire through the dash innards to other side. My self-imposed problem was with the dash plug to which the switch would be mounted. Per Evan's instructions, I had snipped and cut away most of the fins in the middle of plug's backside. My mistake was not making sure enough had been removed to make room for the plastic nut on the back of the switch. I could have easily -- and should have -- tried the nut before soldering the wires to the switch. But now with the soldering complete and the wires smack in the middle of my work area, I had to delicately cut away little bits of plastic until I could get the nut threaded onto the back of the switch. That probably added about 15 minutes to the job.

But I got it done. The whole job, moving deliberately and carefully along the way and counting the extra time needed to correct my flub, took about two hours, maybe a little less.

And it works like a charm. It performs exactly as expected in that 4-stoplight stretch described above: I hit the switch as I pull away from the first light, with enough electric-only acceleration to get me from one to the next without provoking road rage behind me. I turn it off after I pass through the last one and move on to normal acceleration. At other points in my travels yesterday it was cool to be able to shut off the ICE at will when it wasn't needed and wouldn't shut off on its own.

Those who consider the switch should consider the potential for misuse. The clear consensus among current users is that it could cost fuel efficiency if overused, drawing the battery down so much the ICE runs when it otherwise wouldn't. Over the last couple of weeks I've been preplanning when to use it -- and when not to use it -- during my normal travels. That should reduce any tendency for a knee-jerk push of the button just because it seems at the moment like the right thing.

Who knows how much fuel it saves in the long run. I don't plan any controlled studies. But it's cheap and, it turns out, relatively easy to install. And I'm convinced it will save frustration from seeing the ICE running when I know it doesn't have to. That alone makes it worth it.

 

<div class='quotetop'>QUOTE(philmcneal @ May 29 2007, 09:50 PM) [snapback]451797[/snapback]</div>

Hmm, you got me there. I just got word from Norm yesterday that my Can-View was shipping, so it will be a few more days before I get it.

Rangerdavid, my sister lives in Boone, so if I get down there to visit her I'll give you a shout.

 

<div class='quotetop'>QUOTE(efusco @ May 30 2007, 08:58 AM) [snapback]452013[/snapback]</div>

I just reviewed Norm's site, and from what I can make of it, this is an option only with the optional relay board for PHEV conversions. Am I missing something?

Regardless, I think I'll leave the EV button as is. I'm sure I'll be fiddling with Can-view enough as it is.

 

<div class='quotetop'>QUOTE(Rest @ Jun 5 2007, 07:54 PM) [snapback]456105[/snapback]</div>

I'm not exactly sure what you're suggesting, but you don't "reduce speed" just to use the switch. The switch doesn't dictate how you drive; it simply enables more efficient driving at lower speeds. It's one tool of many in the box.

Part of the idea is to enable ICE shutoff at lower speeds where, somewhat paradoxically (IMHO), it's more difficult than at speeds of 35-40. In particular, you cannot do an ICE-off glide from speeds of less than 35 MPH while the car is in S3, which may linger for a considerable time during warmup. Many times during S3 I've either accelerated to 35 just to allow the ICE-off glide or resigned myself to the ICE running during the glide. Either way fuel is wasted. Now at lower speeds I shut the ICE off at will after a brief S1.

I've described other low-speed applications in the original post.