Sunday, February 10, 2013

"Simplify, then add lightness" –Colin Chapman. 

This was the mantra responsible for some of the most interesting cars ever built, and is the antithesis of modern automotive design.  The Build Your Own Sports Car books detail the construction of a Locost, pronounced 'low-cost', which is a play on words regarding an affordable home-built Lotus 7 replica.  A large part of the reason for using the Lotus 7 as the basis for the design is the extreme simplicity of shapes and materials used for the vast majority of the chassis and body work.  If you're not familiar with a Lotus 7, it's a really just a slightly phallic looking pair of pants with an engine.  You don't get into it, you put it on.  It has no top, no windows, and no doors.  The Lotus 7 was among the numerous sports and racing cars designed by Colin Chapman, and was a tiny car with a tiny engine that achieved surprising performance in spite of its lack of power or sophistication.  While a Locost will generally be a noticeably larger and heavier than an actual Lotus 7, to accommodate 'modern' sized drivers, most also have substantially more power from their relatively modern engines as well.  Pretty much any engine that you can think of has at least been considered for use in a Locost.  There are currently running cars with everything from motorcycle engines, to Wankel rotary engines, to good old fashioned American V8's, and even a small industrial diesel engine.  The most commonly used engines though seem to be relatively small 4 cylinder economy car engines that came stock with 100-150 horsepower range. 

Many people who build these cars use a complete donor vehicle, with the Mazda Miata being the most popular in America, harvesting as many parts as possible to reuse.  This includes all manner of parts from the engine and drivetrain, to the suspension and brakes, to the instrument cluster, to the seats, and even to the steering and pedals.  The end result is basically a Miata with more than 750 pounds removed.  This is a very smart way to help a build go more easily, quickly, and affordably.

Apparently following that path requires having more common sense than I was given.  I will be using mostly Ford based components, but it will be 'a la carte'.  As the starting point I have a 2.0L Duratec engine out of a Ford Focus, which will mate to the 5-speed transmission from a Ford Ranger.  The differential and rear upright/brake components comes from a Lincoln Mk VIII, but will be narrowed to a Miata-like width by using Factory Five Cobra rear axle shafts.  Front spindles/brakes come from a 'New Edge' SN95 Mustang, which are actually being reused from my past failed project car attempt.  Also reused from said previous attempt will be the 15" front and 16" rear wheel/tire package.  Even once tuned up a bit, the engine will probably still have less than 200 horsepower.  Nonetheless this should still provide for more than adequate performance from of a ~1500 pound (hopefully less) car, while also still getting moderately impressive fuel economy.

Speaking of fuel economy, the Lotus 7 also holds the unofficial distinction as the highest coefficient of drag production car ever made.  Take THAT Hummer!  Basically what this 'honor' means, is that while its lightweight allows it to perform admirably at low speeds it has poor high speed performance due to aerodynamics.  This also translates into only mediocre highway fuel economy compared to what one should otherwise be capable of with any given engine with so little mass and frontal area to push through the air.  Luckily, the CFO* on this project knows exactly how to make a man happy.  She told me that she preferred to have a more attractive body even if we had to spend a bit of money to get it.  You know the type: classic good looks, curves in all the right places, large prominent headlights, and a shapely backside…Well maybe not in those exact words, but I'm pretty sure it was something along those lines.  Thankfully Jack McCornack at Kinetic Vehicles, one of the pillars of the American Locost community, has been working on just such a set of body panels.  He is currently using the prototype body to help get over 100mpg (yes, you read that right) out of MAX, his 3 cylinder 32hp turbo-diesel powered Locost pictured above.

Now, it's out to the garage to get some work done!

*Also known as SWEETA: She Who Enables Every Thing Automotive

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