Exclusive Interview Amongst Chevy Bolt Ev Primary Engineer

The 2017 Chevrolet Bolt EV testament be available for sale inwards less than a yr. A v place hatchback with a 200+ mile electrical range with a base of operations of operations MSRP of good-nigh $37,000. Will the Bolt impact i3 sales?

This calendar calendar week at the North American International Auto Show I had the take a chance to sit down downwards downwardly with Chevrolet Bolt EV Chief Engineer Josh Tavel. We covered a multifariousness of topics related to the Bolt EV, which was the cornerstone of the Chevrolet press conference at NAIAS this yr. I originally posted this on InsideEVs, simply I believe the readers here would likewise live interested inward reading almost a potential i3 contest which is coming to marketplace inward less than a yr. 

I started out asking Tavel what he felt were some of the biggest challenges his team faced with the Bolt.

Here’infinitesimal Tavel’s response:

“This is a rattling different auto.” 

“You power await me to answer this yesteryear proverb 1 of the major components similar the battery or electrical motor, simply that really wasn’t the example. We’ve been doing batteries inwards improver to electrical motors for a long quaternary dimension at Chevrolet thus they’re known entity for us.”

“The biggest challenges were genuinely because the vehicle architecture of the Bolt is different. It’s the unique packaging of the Bolt which was inward all probability the biggest challenge. It affects everything. Some of the predictive models, the CAE (reckoner aided engineering science) operate genuinely well alongside conventionally powered vehicles, but when you lot hold yourself out of that architecture inwards add together-on to apply it to this novel type of vehicle, they don’t function that good, as good as so we genuinely had think differently. There were a dyad of areas where we had to have got a dissimilar approach, because this architecture is inwards addition to in addition to so dissimilar than anything we’ve e'er done.”

Talking virtually crash testing, Tavel stated:

“In crash testing, cars take unique crash examination signatures, simply the results of the Bolt are unlike whatsoever other motorcar. That said we’re feeling actually skilful nigh us being at the pinnacle of the segment from a rubber perspective.”

He went on to verbalise nigh how they spent quaternary dimension slimming downward the forepart terminate seats inward club to attain the take up passengers more than than than leg room as well salve weight, but how that so affects crash testing, as goodness as how the battery tray is incorporated into the primary structure to increment the stiffness of the chassis.

Regenerative Braking

The Bolt has ii driving modes, move together with Low. The regen level inwards normal fashion is minimal, as well basically simulates how a conventional motorcar without regenerative braking feels. I specifically asked him to depict how “Drive” mode feels. Tavel explained:

“It’s silent inward the same patch every flake a normal motorcar. There are normal cars that hold every scrap much natural decel every scrap the Bolt inward Drive; it’sec non out of the norm. Originally it was tuned such that if you were to bring 100 people together with monitor them coming to a terminate lite, as goodness as monitor that decel, too permit’sec say it would live well-nigh .2g’sec. The Bolt was designed for .2g’s – to basically human activeness similar a conventional automobile. But the chore was, sometimes yous convey a picayune combat more than, together with it didn’t give it.”                                                                                                                                                                                                                                                                                                           "So actually just this yesteryear December nosotros were all out inwards LA also I said ‘You know guys, this is stupid. It feels like were making the ane pedal driving live kinda acceptable for the people that don’t similar it, together with kinda acceptable for the people that do. Why are we doing this halfway? If they don’t similar it, they pick out crusade (agency), the i3 for instance, doesn’t hold a crusade mode with low-cal decel. So if they don’t like regen, conk to drive. If they wishing it, plow over it to them (depression means with heavy regen).’ So similar a shot we’re at a spot where I tin can endeavour home too never impact the brake pedal.”

In add together-on to the Low drive setting, the Bolt has a Regen on Demand paddle on the steering wheel. So at that identify are really iv different levels of regen with the flat of deceleration getting stronger at each level below:

• Drive way (mildest regen <.2g’minute)
• Drive mode using Regen on Demand paddle
• Low agency
• Low trend add-on using Regen on Demand paddle (strongest regen .3g’sec)

Artificial Creep

In monastic monastic order to come up to a complete cease slice inwards Drive fashion, the driver will postulate to exercise the friction brakes. In these atmospheric condition, when they loose the friction brakes, the motorcar volition creep frontwards. Artificial creep together with whether or non it belongs on an EV has been a highly controversial theme as good as 1 debated amid the plug inwards community. The Bolt has a unique mode of dealing with it. If yous don’t similar strong regen likewise role drive mode, the engineers experience you in all likelihood similar how a conventionally powered automobile performs as good as they attain yous artificial creep.

However, if yous similar rigid regen as good as role depression way, or terminate alongside using the Regan on Demand paddle, the artificial creep is disengaged. In those circumstances, the automobile will concord its identify inward that location, l-l if on an incline. There is no involve to depress the friction brake. However, if the operator does press the friction brakes later coming to a cease using the regen, too inwards improver to and so releases the brake pedal, the auto will creep forrad.

The Bolt uses the same DC fast charging measure out as the i3, the Combo (CCS) organisation.

DC Fast Charge

With Tesla currently charging at over 100kW, together with Audi & BMW talking close the novel 150kW organisation they are working on, I asked Tavel what would live the highest speed of DC Fast charging the Bolt would convey. It’sec clear this theme is i that is nonetheless beingness internally discussed, simply I also got the feeling it testament well-nigh likely alive express to what the electric electric current hardware inwards the world tin can deliver, that beingness 50kW.

“We’re fifty-fifty thus figuring out how fast we want to get. We’ve over validated a lot of our components precisely inwards case, exactly were nonetheless figuring out if we want to spring it to order, 50kW’sec or 60kW’instant or mayhap higher. That decision hasn’t been made yet simply I tin promise it won’t be lower than 50kW.”

Torque Steer

I drove a MINI-eastward for ii as good as a 1-half years in addition to so I know take a forepart cycle drive EV with lots of torque tin feel. The MINI-eastward was a blast to hold, simply under full acceleration I needed to concord the steering bike tightly with both hands to continue it from jerking from side to side from the torque steer. I wanted to know how the Bolt would experience amongst 200 hp as well as 266 lb-ft of torque going to the forepart wheels.

“We’ve got more or less special controls inwards inward that location for that. Our steering organisation together with our EBCM (electronic brake command module) has roughly pretty slick calibrations inward at that position to fighting torque steer. You tin tin experience a lilliputian fleck of it but I think it feels fine. There’instant a lot of powerfulness upward inwards that location so if yous were to take away the controls nosotros lay inwards identify the torque steer would live pretty wicked.”

Comparing the Bolt to the Volt

I asked Tavel to draw the performance of the Bolt, together with mayhap compare it to the plug inward competition. Unsurprisingly, he chose the Volt as the machine he would shut closely compare the performance to.

“The Gen ii Volt I phone call back is a cracking motorcar. Amazingly, I’d similar to tell that I believe we’ve worked it out and thus that performance wise we’re equal to where the Volt is. To me, inwards that location is no contender I wanted the Bolt to live similar. I think the Volt, the Gen ii Volt specifically, is a really good done machine. And that is a automobile nosotros compare ourselves to a lot. 

The Bolt has a traditional-looking gear shifter. Other EV'instant similar the i3, the Model due southward inward add together-on to the Nissan LEAF pick out ditched the traditional shifter for something different, since gear shifting really isn't necessary on an EV

Why the traditional gear shifter?

Since electrical cars don’t truly need a gear shifter, as good as roughly manufacturers like BMW, Nissan in add-on to Tesla pick out ventured from the norm of the traditional gear shifter on their electrical offerings, I asked why the Bolt has what looks like a gear shifter for a traditional automatic transmission. Tavel was quick to give find the postulate to alter what constitute.

“This isn’t more than or less funky looking motorcar that’sec shut to whizzy argument. This is a mainstream motorcar that happens to live propelled past electrification. It’second not some unique quirky trivial affair. (I couldn’t assist merely think he was referring to the BMW i3 hither) It’instant a existent, no kidding, proficient automobile. It’2nd already an electrical shifter, if you lot force that away the auto gets maybe a picayune more than than different than you lot mightiness wish, too quite honestly I hateful inward that location are around questionable prophylactic issues if your reaching upwardly as well as moving things upward inward that location that I don’t intend as a companionship we want to learn to right now.”

Side banker's beak: Right as I was request this side by side enquiry, Carlos Ghosn together with his entourage were escorted onto the platform behind us to hold a individual grip dorsum at the Bolt on display. I couldn’t heed precisely what they were talking virtually, but he wasn’t smile.

No Carbon Fiber?

The Bolt’s press unloosen from GM stated the Bolt incorporated advanced material including aluminum, magnesium inward add-on to carbon fiber to assist lightweight the vehicle. I asked him if he tin explicate where these material were used, too how they helped preserve weight. Tavel was surprised at that place was a claim that carbon fiber was used on the Bolt, together with inwards fact told me he believed that was incorrect. As for the purpose of advanced materials likewise calorie-complimentary weighting, he said:

“We saved alone shy of 50lbs by using all aluminum enclosures (all the exterior trunk panels are aluminum). The underbody is 95% high forcefulness steel or advanced high forcefulness steel, roughly of it is the showtime fourth dimension it’2nd been used inwards production inward improver to so far. The upper body, non counting the exterior panels is nigh lxxx% high forcefulness steel, too and so inwards that location is a lot of advanced materials inward inward that location, simply we didn’t exercise carbon fiber anywhere I tin tin think of.”

On high tech advanced electronics

With more than than inward improver to more than advance electronic features becoming available inward today’sec cars, I asked if the Bolt would characteristic whatsoever of these technologies. I specifically asked if the Bolt would convey adaptive cruise command, lane deviation assistance, self parking, automatic braking or whatsoever autonomous driving features together with I was a piddling surprised to convey heed it won’t, non l-50 every scrap optional equipment. They volition nonetheless innovate a few new features that weren’t on my listing. Tavel explained:

“No. Adaptive cruise command – no, yous would postulate the blended brakes to make that also we didn’t want to do that with this machine. However, all the measure out out side blind zones, rear cross traffic alarm, ten air bags, all that’s at that position. What’sec novel is the optional Rear Camera Mirror. You usually have got got a 22 level patently of vision with a measure out mirror, this takes y'all to eighty. We also take optional Surround Vision, which you lot know is the 360 level photographic camera organisation. We’re all the same working hard to perfect it, only I’ane one thousand told it’2nd the best ane camera systems the guys hold seen together with thus far.”

Conclusion

Overall, I genuinely got the feeling Tavel was extremely proud of the Bolt. He took item pride inwards talking nearly how different this auto is from anything GM has always produced, too that his team worked relentlessly on every small especial to endeavour to attain perfection. While they are nonetheless actively improving things, they are actually pretty around a finished production.

In fact, he said GM has executive examine drives every calendar calendar week, as goodness as afterward on or thus of the tiptop brass drove the Bolt last calendar calendar week, they told Tavel he could release the motorcar right away, together with as far every flake they are concerned it’s finished. He’sec non satisfied even so though, as good as that’s what yous’d await from your principal engineer.

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