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Posts Tagged ‘Road & Track’

Technical Minutiae

November 9th, 2009 Comments off

When it comes to cars, I’m fascinated with technical minutiae.

In the tech Q&A section of one of the car magazines I read, the question was recently posed, “Are there any disadvantages to direct-injected engines?”  Many automakers are switching from port-injection to direct-injection in an effort to increase performance and fuel-efficiency.  (What’s the difference?  In traditional port-injected engines, fuel is squirted into the incoming stream of air before it goes past the intake valve into the combustion chamber where it is ignited.  Direct-injection, on the other hand, involves injecting the fuel directly into the combustion chamber – and air is the only thing that enters via the intake port.)  Direct-injection is used in many high-end and mainstream vehicles now, and will probably make its way further down-market very soon.

MicroscopeTurns out, there are a couple of concerns with direct-injection that aren’t immediately obvious.  One involves the intake valve itself.  Along with the air that flows past it is the small amount of gases that leak past the piston-rings and into the crankcase, returned into the intake stream via the PCV (positive crankcase ventilation) valve. This is essentially the “oily” air that resides in the bottom half of the engine.  Over time, the PCV system could cause oil-residue to build up on the back-side of the intake valve.  In an older port-injected engine, the gasoline washes this residue away, but in a direct-injected engine, this residue never gets cleaned off.  (Ford solved this problem by adding an additional filter to the PCV system.)  Another concern is that directly injecting gasoline into the cylinder could wash the oil-film from the cylinder walls, increasing wear of the rings.  My guess is that this will turn out to be a non-issue, given the amount of testing that goes into proving the fundamental combustion processes of engine technology.  But this is what I find fascinating – there are significant repercussions to even slight design modifications.

It’s sort of the law of unintended consequences.  (Increased ethanol production caused a spike in the price of tortillas, anyone?)  Not long ago, I had a conversation with an automotive engineer that was studying the role that lubricants (i.e., your motor oil) play in auto emissions – a role that is increasing as vehicles become more fuel-efficient.  Motor oil formulations have been (and will continue to be) altered in order to reduce their contribution to tailpipe emissions.  As an example, the amount of zinc dialkyl-dithio-phosphate (ZDDP) was recently reduced in engine oils, due to its detrimental effects on emissions equipment (such as catalytic converters) over time.  Unfortunately, it’s the ZDDP that helped to protect the metal-to-metal impact surfaces in engine valve-trains up until the 1990s.  Owners of cars built before then are now experiencing increased camshaft and lifter wear, upsetting a lot of folks who drive classic (and near-classic) cars. …A slight change somewhere results in unforeseen consequences somewhere else…

At this point, if you’re still reading, your eyes have probably glazed over.  Technical minutiae isn’t for everyone.  But sometimes, it’s the tiniest of details that matter.

Porsche Goes Lithium, Saturn Leaves Orbit

October 8th, 2009 Comments off

Buried in the pages of the November issue of Road & Track is a short description of the 2010 Porsche 911 GT3 RS.  (For those unaware, the 911 is Porsche’s bread-and-butter sports car.  The GT3 version is the ultra-high-performance, race-bred version of the 911.  The RS is the insane, barely-street-legal, over-the-top version of the GT3.  It’s the one I want.)  It’s got all the goodies you’d expect, but one option really sticks out in my mind: a lithium-ion battery to replace to the conventional lead-acid battery, resulting in a 22-pound weight reduction.  Now, this isn’t a hybrid or electric vehicle of any sort.  The battery is used, as it is in any conventional car, to turn the starter and to power the accessories when the car’s not running.  And while racers have used down-sized lead-acid batteries (barely capable of starting the car) for weight savings for quite some time, this is the first time I’m aware of that a manufacturer has offered a Li-ion starter battery.

There are folks that criticize Li-ion batteries as being too unsafe and too expensive to be a real solution to automotive energy storage.  There are even those that suggest lead-acid batteries are more than capable of storing the energy we need in hybrid and electric vehicles, not to mention the starting-duties of internal combustion engine cars.  (I’d agree with respect to starter batteries, but certainly not the other points.)  But now Li-ion has made it’s way into what most would agree would be lead-acid’s territory for the foreseeable future!  Sure, it’s probably an expensive box to check on your GT3 RS order form, and it really is a niche application.  But it may also be a glimpse into the future of automotive batteries.  (Though I do find it ironic that Porsche is offering this option to save 22 pounds – less than 1% of the weight of the vehicle – while they’ve refused to offer weight-saving and arguably more practical options on their GT3 to the North American market in the past, such as carbon-fiber fixed-back racing seats.)

2010 Porsche 911 GT3 RS

2010 Porsche 911 GT3 RS

In other news, it was announced over a week ago (and how did I miss it?!) that the deal whereby Penske would acquire the Saturn brand and sell vehicles under a contract-manufacturing agreement with various automotive OEMs won’t happen happen after all, and the Saturn brand will disappear.  I find this disappointing, simply because it was a new business model in the automotive world, and I was interested to see how it would work out.  Unfortunately, I guess I now have my answer:  not well.

Perspective

September 2nd, 2009 Comments off

I’m a car guy, and an environmentalist.  I made that clear in my inaugural post.  I’m proof that these two perspectives aren’t mutually exclusive.

In The Road Ahead column in the October issue of Road & Track, editor-in-chief Matt DeLorenzo likens the freedom and spirit of the American cowboy to the mobility now afforded us by modern cars.  (It’s a reasonable analogy, given that the feature article is about the Ford Mustang, Chevrolet Camaro, and Dodge Challenger – 3 American “pony” cars that have recently been resurrected.)  He also makes the very correct point that “the automobile has a social cost – clean air, use of resources, accidents … [that] must be weighed against the benefits – mobility, freedom and independence.”  (OK, “freedom and independence” may be a bit of a stretch, but you get the point…)

Unfortunately, DeLorenzo goes further, and says “there are those who can’t abide these freedoms … [and] would rather see the American cowboy unhorsed.”  He suspects that the push for cleaning up the environment and improving fuel economy is “cover for a larger agenda” to force people to stop using automobiles.  He views this point of view as largely coming from “sophisticates (usually from big cities or across the ocean)” who view our constitutional rights as “merely incidental.”  He effectively equates reducing the environmental impact of our transportation to the demise of one of the great patriotic symbols of America.  (We won’t get into what the great American cowboy did to the Native Americans here…)

…Really?  Does DeLorenzo really belive that there are folks that want to prevent other folks from driving simply because of a desire to suppress others’ rights?  (OK, I’m sure there are one or two such people out there, but they probably also believe that the Apollo moon landings were faked.)  While the “sophisticates” who live in large metropolitan areas might be more likely to place high importance upon improving fuel economy and finding other modes of transport, it’s because the social cost (as DeLorenzo correctly described it) of millions of inefficient automobiles is much higher for them than it is for Johnny Tumbleweed piloting his Mustang across Wyoming – at least insofar as the noise, congestion, and pollution that result.  (Greenhouse gases, on the other hand, will affect Mr. Tumbleweed just as much as they will Winston Urbandweller.)

It’s valid to argue what the real social cost of our automobile use is.  But to suggest that it’s all a ploy to get people to stop driving, while hinting that the effort destroys a piece of American heritage, is ridiculous.  I’m offended – as a car-guy, and as an environmentalist.

cowboy

Lose Some Weight, Will Ya?

July 15th, 2009 Comments off

An article in the current issue of SAE‘s Automotive Engineering International (“Everything but the Engine”) discusses the effect that components other than the engine have on vehicle fuel efficiency.  Among the items discussed are transmissions and the benefits of DCTs (which I previously talked about here) and tire rolling resistance (which I previously talked about here).  (…Wow, I’m very timely, aren’t I?)  Other efficiency mechanisms discussed are reducing vehicle size, using advanced lightweight materials, improving aerodynamics, and reducing the weight of all the accessories that are packed into what have essentially become condominiums on wheels.

Buick Enclave Rear Suspension

Buick Enclave Rear Suspension

Let’s talk about weight.  Our cars need to go on a diet.  I remember last year reading a Road & Track article about the new BMW 1-series (finally, a small BMW to replace the formerly-small 3-series!), and my jaw hit the floor when I saw how much it weighs – 3373 lbs for a manual 135i?!  This is small car?  …At the other extreme, my wife’s Buick Enclave has a curb-weight just shy of 5000 lbs, despite the use of aluminum in some of the body panels and suspension components.  (The Enclave’s aluminum rear control arms are a thing of beauty, though.  GM did do a few things right.  …Am I the only one for whom control arm material is a criteria for purchasing a vehicle?)

More extensive use of light-weight materials such as aluminum, magnesium, high-strength steel, and carbon fiber can reduce weight, but it seems like automakers are more focused on making cars more bloated while using these materials to offset a portion of the weight-gain that would otherwise occur.  (They add 100 lbs of features, but only 75 lbs of weight!)  On the other hand, my race car weighs a scant 2500 lbs, and that’s with an old-school steel tub, a heavy steel cage, and 70 lbs of ballast in the floorboard.  And in its day it would carry 2 adults and 2 children (sans cage) plus their luggage.  Granted, it lacks all the amenities that consumers demand today.

Lightweighting is a good thing, with compounding benefits.  Reducing the weight of the vehicle means a reduction in the size of the engine needed to move it around, smaller brakes to stop it, and lighter suspension components with which to control it, all of which lead to further reduced weight!  At the same time, handling is improved and stopping distances are reduced.  So, why haven’t we seen this in our cars?  One answer is that many of the advanced materials are still too expensive to be cost-effective.  Secondly, consumers demand more and more comforts such as DVD players, Ipod adaptors, Bluetooth connectivity, Big Gulp holders, and hip room.  Finally, some argue that smaller and lighter-weight vehicles are less safe, backing it up with statistics showing increased fatalities for occupants of such vehicles.  And while it is true that today’s small vehicles won’t fare as well in a crash with a Ford Excursion as the Excursion will, this does not take into account the effect that smarter design and the use of advanced materials have on occupant safety.  Cars aren’t like billiard balls – there are many more dynamic forces at play, and heavier doesn’t necessarily mean safer.

Automakers need to build small, lightweight cars – not small versions of what they already build.

The Art of Racing in the Rain

July 13th, 2009 Comments off

My dog died today.

I’m not a reader.  I mean, I read non-fiction books and magazines (about cars, mostly).  But, I only sit down to read a novel about once a decade.  That “once” came last summer, when I read Garth Stein’s The Art of Racing in the Rain.  I bought this book because it was recommended in Road & Track, and when a car magazine recommends a novel, you’ve got to figure it’s not just another book.

Stein - Art of RacingThe Art of Racing in the Rain is a book about balance, anticipation, and patience.  It is told from the point of view of Enzo (whose namesake, Enzo Ferrari, founded the maker of those prancing-horse-emblazoned Italian automobiles in 1947).  Enzo is a dog who’s at the end of his life, and in the book he reflects upon all of the events that have occured during his time with Denny, his owner and an aspiring race car driver, and Denny’s wife Eve and daughter Zoë.  Now, I really have no frame of reference with which to compare it, but this is an incredible book.  If you love dogs and/or racing, you must read it.  …My wife has long said I am unemotional.  That may be true, except when it comes to dogs and cars.  And The Art of Racing in the Rain nails it on both accounts.

In racing, rain is the great equilizer.  It makes the track unpredictable, and increases the chances of the unexpected.  (I’ve had three on-track wrecks, two of which were in the rain.)  I found out my dog (coincidentally, named Zoe) had cancer a little over 5 weeks ago, when I took her to the vet to fix a broken tooth.  Her symptoms had just started, but at that point the mass was too large to do much about.  Talk about the unexpected…  Her health declined rapidly over the past month.

I read The Art of Racing in the Rain last summer just after driving from North Carolina to Colorado, by way of Utah.  Zoe was my companion for the trip.  I was thankful to have her with me, as she was a good listener, and she forced me to pause for rest-stop picnics and to stretch our legs every now and then.  I missed her tremendously when I had to leave her in Utah while I was in Colorado for 11 weeks.  …I’m going to miss her a lot more now.

Zoe, October 17, 1999 - July 13, 2009

Zoe, October 17, 1999 - July 13, 2009