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May 7, 2009 10:00 AM PDT

What should a hybrid sports car feel like?

by Antuan Goodwin

Fisker Karma Concept (Credit: Fisker Automotive)

Gasoline/electric hybrids have been around for almost half a decade. In this time, automakers have--through tweaking and borrowing ideas--homed in on how a thrifty and efficient hybrid vehicle should look and feel: essentially, something like the Toyota Prius.

With that all sorted out, automakers started to look at other vehicle segments to which they could apply their hybridization magic. Trucks, SUVs, and even large luxury sedans drink less fuel as the result of an electric motor being tossed into the drivetrain mix. Yet, until recently, one segment has managed to stay off of the greenies' radar: sports cars.

However, with vehicles like the Fisker Karma on the horizon and rumors of Nissan mulling a hybrid 370Z, sports car enthusiasts find themselves alternating between outrage and excitement about what the future may hold for sustainable motoring.

Nissan 370Z

So, would they call it the Nissan 370ZH?

(Credit: Nissan Motor Co.)

When you consider the instant-on torque that is characteristic of the electric motor, it would be interesting to see what a no-compromises, performance-oriented hybrid drivetrain would feel like in a lightweight, rear wheel drive sports coupe.

However, when you consider that most manufacturers can't even build an automatic transmission that can outperform a good old fashioned manual gearbox, the prospect of even more techno-foolery between the driver and the meat of the tires is a bit scary.

In my opinion, adding hybrid technology to the sports car formula without mucking the whole affair up involves getting two things right: keeping the additional weight of the electric components low and making the technology transparent.

In the world of sports cars, weight is bad, and adding even the Toyota Prius' 150-pound battery pack results in slower acceleration and less responsive handing. That doesn't even include the additional weight of the electric motor, transmission components, and additional wiring. (Yes, I said wiring. Every ounce counts!) In a hybrid sports car, weight (or at least the center of gravity) must be kept low.

Sports cars are quite often small and bare-bones, lacking large trunks and storage spaces that can be sacrificed to store the battery packs. So the additional issue of where to put the batteries is created. No wonder the first hybrids were small SUVs with plenty of space!

Then, there's the bigger bombshell issue of technology transparency.

For the most part, sports car guys are sort of Luddites, at least where the drive train is concerned. Don't believe me? Google "Synchro Rev Match" and read some of the condescending things drivers have to say about Nissan's newest feature. But who can blame them? Historically, adding too much technology to the mix has dulled the driver's connection to the vehicle. (I'm looking at you, torque-converter automatic transmission!)

Subaru Impreza 2.5GT shifter

Years of poorly performing automatic transmissions has made enthusiasts wary of technology.

(Credit: Corinne Schulze/CNET)

Only recently, with the widespread acceptance of DSG, SST, PDK and other double-clutch, automated-manual acronyms and advanced all-wheel drive systems have enthusiast drivers begun to accept that perhaps tech can be a good thing for performance. Which brings us back to the idea of hybrid sports cars.

For the most part, people's conceptions of how a sports car's hybrid drive train would feel end up right back were we started with the Prius. However, I contend that the template for a sports car hybrid is, at this point, a blank slate. There is no high performance hybrid being manufactured on a grand scale today (unless you count the Lexus GS450h, which I don't).

I've always thought that a good performance hybrid drive should work something like an inverted turbocharger (building power at the bottom end of the powerband with instant-on torque, instead of at the top like a spooling turbo) making a small motor feel larger and torquier, while maintaining efficiency, or removing the feeling of lag from a turbocharged engine. Power transitions should be smooth. The driver should only feel an increase in power, not two powerplants fighting for control of the driven wheels.

Alternatively, a performance hybrid could work something like an old-school exhaust bypass switch or the M-Power button on a BMW M-car, operating efficiently until a Mr. Hyde button is pressed and the power of the electric drive train is uncorked.

We're interested in hearing what you think the performance hybrids of the future will look, feel, sound, and smell like. Is such a thing even feasible? Sound off in the comments section below.

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Add a Comment (Log in or register) (19 Comments)
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by phaselocke May 7, 2009 12:10 PM PDT
from a transmission standpoint, it should be feasible to have an "M" switch that changes the software controlled CVT ratios from "energy-efficient" to "power optimal".
Reply to this comment
by theBike1945 May 7, 2009 12:20 PM PDT
The "mucking up" going on here is the article's confusion concerning hybrids. A serial hybrid , such as the Fisker pictured, does not have "two drivetrains." It is an electric car, ala Chevy Volt, with a range extender, which, in the case of the Fisker can be brought to life and operate in parallel with the charged battery to produce more kilowatts than the relatively small (but costwise very economical - compared to the Tesla) battery pack could provide by itself. Any such hybrid, given a motor with a larger capacity than its battery pack, could adopt the same strategy (the Volt-like Cadillac will also do this) . It's nothing more than a software change. The Fisker has only an electric drivetrain, and that's all the driver will feel
propelling the car. If done properly, he won't even be aware that there are two motors running simultaneously.
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by TCrimson05 May 7, 2009 12:23 PM PDT
Definitely feasible. I'm already intrigued by Tesla and Fisker Karma. I wish Brian Cooley could get a "Hands On" of the Ronn Motor Company's - Hydrogen Hybrid "Scorpion". That would be sweet.
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by czarak May 7, 2009 5:04 PM PDT
A hybrid sports car could be a parallel hybrid like the Prius, with equal power for the electric motor and engine, but 100 Kw and 150 hp in a 3000 lb body. Battery the same 150 lb. To be effective, regenerative braking recovers most of the energy in full braking, recharging the battery, energy which is then available for accelerating out of the corners abd down the straights. Since the battery is used when accelerating and recharged when braking, with part of the engine power compensating for the lack of efficiency of the electric side, this capability works indefinitely as long as there is gas in the tank. It might be feasible...
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by twriter May 7, 2009 6:43 PM PDT
A hybrid sports car should be the Mini Cooper, with the rear "seat" essentially replaced by the battery (although likely also creating additional--and sorely needed--trunk space), getting 70-80 (or more!) MPG. C'mon BMW engineers, you claim to be the best automotive engineers in the world. Let's see you prove it.
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by Slandy May 7, 2009 7:06 PM PDT
Of course it's possible, just depends on the execution. You really need to get your facts straight, though. First, hybrids have been on the market much longer than "almost half a decade." The Honda Insight was introduced in NA in 1999 as a 2000 model. Toyota introduced the Prius in NA in 2001 (Japan in 1997). Second, "...the first hybrids were small SUVs..." Wrong again, see first point. The Ford Escape was the first hybrid SUV, introduced in 2004.
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by illegallydead May 7, 2009 9:29 PM PDT
My opinion: do as theBike1945 described in terms of what sort of hybrid. Makes things much simpler, without having to switch power sources, which could be killer (killer as in bad, like kill you killer if you're taking a turn hard and all of a sudden you lose power as the car "decides" to switch power sources)
Not to mention, an engine working solely as a generator can be better tuned as such, and could run at a constant RPM without varying strains, meaning it could be that much more efficient.

However, if you want all-out, balls-to-the-wall power, do independent motors. I'm talking a motor on each wheel, giving you 100% true all-wheel-drive, and without the horrible loss of efficiency created by the driveshaft, etc. in every other car on the road. This thing would be a beast in terms of cornering, and you would lose the weight of the driveshaft, central tranny, etc. making the car that much lighter.

If cost is not an object, than do as much carbon-fiber as possible, and probably lithium-ion for the battery pack. Lose as much weight as possible and be sure to position things so as to keep center of gravity low and well balanced. Perhaps batteries up front, generator in rear?

Anyway, that would be my approach...
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by omair-s May 9, 2009 1:58 PM PDT
Good one.v =)
by curtiskelowna May 10, 2009 9:35 PM PDT
the thing with 4 individual motors is that they would eventually (or initially) have slightly different accellerations. It would need to be monitered and adjusted by a computer. But then again thats not a big deal.

By the way, toyota was prototyping an electric sports car which had a motor for each wheel...
by 4popoid June 3, 2009 8:15 PM PDT
Now we are talking. Four "wheel-motors" (be careful of the undamped mass), with no drive shafts u-joints, etc., packeged with a nice light weight four cylinder engine driving a good sized alternator (flywheel alternator perhaps). The battery pack should be large enough to provide 75 miles of battery only in city/suburban driving, using regenerative braking. The engine/alternator would kick in (constant speed) to replenish the battery, and provide backup boost for highway/aggressive driving. Provision for alternative plug-in charging should be provided as well.

Put this arrangement into a lightweight 2-seater with decent trunk space and price below $30K and you would have a sure winner. A retractable hardtop (ala Mazda Miata) wold be a nice bonus, but be careful not to sacrifice too much trunk space or add too much to the price.

I would by such a car in a heartbeat.
by raffr May 8, 2009 5:36 AM PDT
The only way I can see a hybrid sports car working is if you follow the Honda formula with an integrated motor. This will allow the eletric motor to act as a sort of electric supercharger, not really driving the car like the Prius set-up . It would also allow you to keep the weight down with a smaller battery pack . If a car has a CVT, it is not a sports car, period. I am look forward to the Honda CR-Z, as long as it has a manual transmission.
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by Dissenter77 May 9, 2009 1:12 PM PDT
The first question should be; How much horsepower equates to something being a sports car? From the forums, the area of 300 hp is a minimum. Honestly, as much as I believe the time has come to go "green," this technology should have been started 20+ years ago. CR-Z @ 140 hp? Boring! I have a Nissan 350Z, modified, and if these companies can't offer me upwards of 300-350 hp, what good does their technology do for me and others who own sport cars?

So debate all you want on how to get that so called "power." A sports car is not 150-200 hp with 125 lb/ft of torque. LOL!!!
Reply to this comment
by tcr071 May 10, 2009 8:55 AM PDT
The Tesla Roadster has 248 horse power and will blow past your 350z with ease. 0-60 in less than 4 seconds. The Roadster Sport has 288 horse power and will blow past the regular roadster.

Both cars are 100% all electric and will embarrass your 350z off the line and 0-60. I'd classify them as sport's cars based upon their performance but if you want to go off of horse power, which doesn't tell you anything about a car, that is great.
by curtiskelowna May 10, 2009 9:39 PM PDT
The tesla roadster has less than 200 hp but yet can go 0-60 in under 4 seconds (i think 3.9). Thats almost as fast as the bugatti. When it comes to electric cars i dont think horsepower really says how much the car can do.
by curtiskelowna May 10, 2009 9:40 PM PDT
lol i got my facts a bit off but the guy before made my point. Sorry for innacurate references
by sdownes_2000 May 9, 2009 7:24 PM PDT
The instant torque offered by the "electric" route is intriguing from someone who has been brought up on 0-60 times rather than Top Speed. I have always loved the low-end torque of a VW (non-diesel), but enjoyed the all-out thrill of a Honda VTEC at high revs. These are four cylinders I am talking about here that do not sacrifice lightness for power. Power-to-Weight is everything and this is where the hybrid system gets a little cloudy.

Has anyone been following the use of the KERS (Kinetic Energy Recovery System), as used in Formula One? I know some of these systems are not true hybridization by general definitions, but the added weight has been giving the chassis engineers headaches, but the extra 80HP or so produced by the various systems have given significant boosts in speed, although they have only just realized that the boost for the car trying to overtake is nullifed by the boost that the driver in front can also access!

Finally, let's not forget handling, which is my number one priority. The car I drive is not quick off the line, but it handles wonderfully and has excellent acceleration above 30MPH. Power is not everything. Anyone ever driven a Mazda Miata? Don't tell me that is not a sports car! :)
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by curtiskelowna May 10, 2009 9:42 PM PDT
im not really sure how horsepower is measured.....does anyone know how they test it?
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by markb1967 May 11, 2009 6:15 AM PDT
screw the hybrid and give me a totally electric vehicle.
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by Scott Gardener May 11, 2009 10:28 AM PDT
I've wondered for years why we weren't seeing electric power and instant torque used in anything short of the Lexus GS450h. I'm really looking forward to seeing Tesla Motors owning the American auto industry with a capital "P."
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