Published on March 14th, 2014 | by Jo Borrás0
Porsche 919 Deep Dive: Secrets Of Porsche’s New Hybrid Revealed
March 14th, 2014 by Jo Borrás
Porsche isn’t messing around with its new Porsche 919 Hybrid race car. For starters, they’ve built a slippery, aerodynamic racer and hired Formula 1 ace (and damn near 2010 World Driver’s Champion) Mark Webber to drive the thing at this year’s 24 hour LeMans race. Next, they’ve designed the car that is able to harness more of the potential energy in gasoline than anything else. How did they do it? Read on.
I’ve never met the Truth About Cars’ Ronnie Screiber, but all evidence suggest that he is a clever cat. As he points out in his own, highly-detailed Porsche article, gasoline contains about 116,000 btu/gal. That means we have a significant number of BTUs that we can turn into energy, even in an internal combustion engine with theoretical maximum efficiency of 37%. That means that, even under ideal conditions, nearly 2/3 of all the energy in a gallon of gasoline is either wasted or lost as heat.
To begin getting some those lost BTUs back, Porsche went down the same path Renault did with its new Formula 1 engine: turbocharging.
Turbos are “spooled” by the pressure of the engine’s exhaust– a product of combustion. The exhaust gasses drive a turbine that compresses and forces more oxygen into an engine’s combustion chamber, generating greater thermal efficiency per unit of fuel than a normally aspirated (non-turbocharged) engine. In the 919 Hybrid, the turbocharged 2.0 liter 4 cylinder engine is fitted with an additional and “fundamentally new” exhaust-driven device that sends power to the hybrid’s batteries.
That exhaust driven turbo/hybrid charging system looks like this …
… and sort of sits in Porsche’s 919 Hybrid thusly …
… keeping the entire power-generating package light, compact, and neatly integrated underneath the car’s tightly-pulled skin (shown, below).
Now, I know that many of you looking at that cutaway are thinking that Porsche’s 919 Hybrid powertrain looks pretty small for contesting LeMans. Consider, though, that they’ll be turning as many as twice the number of available BTUs into heat energy as most of the field, so think of that 2.0 liter turbocharged V4 as more of a 4.0 liter twin-turbocharged V8 and you’ll start to get the idea. Factor in the reduced wear and tear the lighter engine will put through the tires, the extra life they’ll get out of their brake pads thanks to the regenerative braking strategies being employed, and the improved fuel economy available to Porsche’s hybrid and you might start to understand why Mark is one of the odds-on favorites to win this year’s event.
It’s all pretty clever stuff, for sure- but will the new turbo/hybrid system give the new 919 enough juice to win against the dominant Audi and Toyota teams at this year’s 24? We’ll find out in June. Until then, you can see more of the new Porsche 919 hybrid in Gas 2’s extensive photo gallery, then let us know what you think of Porsche’s new hybrid tech in the comments section at the bottom of the page. Enjoy!
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