Turning 21 can change one's outlook on life. Doors open, responsibility comes calling. Pints are sipped at a bar, not chugged in the back yard. For the Honda Civic Si, the occasion has been both a return to form and an opportunity for growth. The current, sixth-generation Si - based on the eighth-generation Civic platform - abandons all that was wrong with its immediate predecessor, makes more power than any other Civic, and, in a first for the U.S. market, is available as a sedan.

Still, today's hot Civic enjoys a following not terribly different than that of the original Si, based on the third-generation Civic. Like that car, the 2007 model appeals to gearheads, autocrossers, and dedicated Honda enthusiasts. The first and most recent Si models are bookends to a collection of stories of trials, tribulations, and big, silly spoilers and exhaust pipes. We've gathered examples of these two in one place to take a closer look at the Civic Si's coming of age.

Some Si Backstory
By the early 1980s, Honda's Civic had already developed a strong reputation for reliability and economy - credentials that, following a fuel crisis and the nadir of American car quality, made the Civic plenty of friends. Those friends, however, valued Civics for its Consumer Reports virtues, not anything that made drivers' hearts pump. Civics weren't even a dim blip on enthusiast radar screen until 1984's third-gen redesign brought with it a more sporting "S" trim level hatchback and the fastback CRX, and those cars still shared their 76-horsepower economy engines with the commuter all-star models.

That changed for model-year 1986, when Honda gave the Civic hatchback the same fuel-injected engine it had installed in the CRX the year before. Displacing 1.5 liters and with an odd number of valves for each cylinder (two tiny intakes and one single, honkin' exhaust), the SOHC mill was good for 91 hp at 5500 rpm and 93 lb-ft at 4500. While those may sound like small numbers, remember that, compared to the porky, safety-laden cars of today, the Civic was a bantamweight: Even with a full tank of gas and a driver, the car teetered on the brink of 2000 pounds. Since it was based on the carbureted Civic S, Honda added an "i" to the badge to denote fuel injection, and the result - the $7999 Civic Si - has become, arguably, the modern-day equivalent of the 1932 Ford.

It took a while, though: While enthusiast interest in the car built steadily through the Si's second and third iterations, the high-performance Civic concept catapulted to rock-star popularity with the fourth-generation Si coupe. With BMW-like proportions and a 160-hp B16A2 VTEC engine, it became the car to have within the compact tuner scene, where commonly seen mods like cartoonish body kits and coffee-can exhaust tips made the new Honda-loving set the target of numerous ricial slurs.

But fame is a cruel mistress, and the spotlight inevitably moves away. For the Si, this happened when the quirky and misunderstood fifth-generation hatch failed to excite the tuner crowd. Now that the Civic is no longer the flavor of the month, today's sixth-generation Si has settled back into a sensible-performance role. It enjoys a following not unlike the original, which is to say much more loyal to the virtues of the car and to Honda itself.

Old and New, Side by Side
Finding a clean first-gen Si in today's disposable world isn't terribly easy. Civics were utilitarian cars, and most logged more than their fair share of mileage. Many of them succumbed to the elements and rusted into disrepair, while others were modified beyond recognition. Fortunately, we found a worthy example in the sticks of Virginia owned by Joey Zarrella. His white '86 hatchback has over 235,000 on the original engine and transmission.

Sliding into the '86 is like getting reacquainted with an old friend. Even if you aren't familiar with Hondas of the time, the dash and controls feature a smart, traditional layout that you could have found in almost any of its contemporaries. Some interior styling cues, like the dashboard that wraps around into the door panels, were ahead of their time. Others, like the orange-lit clock marked "QUARTZ" sitting in front of the passenger, seem self-consciously futuristic. Orange letters also bedeck the Si's 120-mph speedometer and 8000-rpm tach, whereas the standard Civic uses white. Big, plastic sliders control the airflow and temperature, while a chunky rotary knob works the vent fan. The plastics don't feel too cheap considering the build date, and creaks and groans earned by its 235,000 miles are largely limited to the rear hatch.

A lack of power windows or power steering were just two of the many ways this car was able to tiptoe lightly down the road. Safety elements such as ABS and airbags weren't even considerations at the time, and are additional mass this car does without.

Today, ABS is standard fare on even the lowliest Civic. Honda also added stability control (VSA) for the 2007 model year, again standard for the entire Civic range. Purists and track rats may grouse over the addition of the latter, but systems such as these have proven their worth in daily driving conditions.

Doors on the new car open with more heft than our original Si specimen, a reminder that this is the heaviest Si to date. The '07 coupe weighs in at 2877 pounds, over 800 more than the '86. It's also about three times as expensive, yet still represents real value: As tested, a car like our Taffeta white coupe with XM-linked satellite navigation and summer tires will set you back $23,040. There's a destination charge of $635 and a host of dealer-installed accessories, but the Si comes basically loaded save the sat nav.

The new car's interior is handsome, with deeply bolstered, dual-density-foam sport seats trimmed in black cloth. Alloy pedals and a sleek, red-mapped, alloy shift knob add to both the performance look and functionality. Contrasting red stitching and faux aluminum trim also contribute to the ambiance, while Si logos on the seats and tach are reminders that this is no base Civic.

If you've left the key in the ignition, you're greeted with the same door chime as in the older Civic - evidence that some things don't change. And like the first Si, the new car's dash is a combination of driving enthusiast rationality and futuristic kitsch. Functional-yet-sci-fi, the squared-off steering wheel is fat and grippy, with audio and cruise controls built into spokes at 9 and 3 o'clock. However, it's the two-tiered instrument array and expansive dashboard that really evoke 2001: A Space Odyssey. Peer through the wheel and you'll see a large tach sandwiched between clusters of indicator lights on either side. Above the wheel, an all-digital speedo is very precise, but you have to train your eyes to find it.

Those familiar with Honda and Acura products will appreciate the optional double-DIN audio unit, complete with XM Satellite Radio, satellite navigation and 350-watt sound. The touch screen works well, the navigation maps are easy to read, and Honda includes an auxiliary input jack for iPods and such.

Exterior packaging for the new car is handsome and subtle in typical Honda fashion. Visual differentiation from the standard Civic is kept to a minimum. The Si gets a unique color-matched grille insert, a larger rear trunk spoiler, and "Si" badges front and rear. It also gets handsome 17x7 split 5-spoke alloys with Michelin Pilot Exalto PE2 summer tires. The only other identifying exterior element on the car is an "i-VTEC" graphic on the lower rear valance that hints at what's underneath the hood - a 197-hp 2.0-liter 4-cylinder with intelligent VTEC variable camshaft timing.

Back in '86, Honda added a body-colored front airdam, color-matched bumpers, and a rear roof spoiler to help the Si look the part. The original car also got dual mirrors, a removable glass sunroof, full-width taillight panel, and the same disc-style wheel covers from the Civic sedan. American cars did without the bulged hood or four-hole alloys that were standard on Japanese-market cars.

Our early example isn't entirely factory correct. Outside, Zarrella replaced the steel wheels and hubcaps with dark gray Panasport-style alloys. He also swapped out some soggy suspension bushings and cracked rubber brake hardware with upgraded parts to beef the car up for weekend track days at West Virginia's Summit Point. The body, however, is mainly untouched save some as-needed rust repair, with a chrome keylock on the fuel door standing as a stark reminder of the fuel-crisis era that gave rise to the Civic's popularity.

The first-gen Si fires up with no audible or visible complaints and settles into a smooth and rhythmic idle. The 5-speed shifter slides precisely, despite two decades of spirited driving. It's worth noting that when this car was new, an unknown division of GM called Saturn was designing a car from the ground up, and this transmission - not a Getrag unit from a German car - is what they decided to benchmark.

This early Si will win few stoplight run-ins with modern cars. If you have 8.9 seconds to spare, the Civic Si will hand you 60 mph, and will continue on to finish a quarter of a mile in 16.9 seconds. There's enough torque to cruise in fifth at off-highway speeds, until you hit an incline and are forced to search for a lower cog. Like many modern Hondas, this Civic lives for higher revs. Above 4000 rpm is the engine's happy place, but its pre-VTEC engineering means the power drops off as it inches closer to the 6500-rpm redline.

By contrast, the new i-VTEC 2.0 starts with a purr. Taking the metal shifter in hand and reaching for a gear, you'll find a positive and precise six-speed transmission that's as fun to row through as the manual in Honda's S2000 roadster. The icing on this drivetrain cupcake, though, is Honda's standard implementation of a rare-for-its-class helical limited-slip differential to help get power to the ground and improve the handling characteristics of this front-driver.

Handling is further improved thanks to a completely re-tuned suspension. Higher-rate springs, 45-percent stiffer dampers, larger anti-roll bars front and rear, and larger front brakes make this chassis considerably more competent than the base car's.

The new Si remains quite composed cruising around town. Accelerate with more abandon, though, and the car gives back willingly. Reasonable performance figures for this car are 0-60 in 7.2 seconds, and a 15.1-second 1/4-mile time. Even with the Si's standard mechanical limited slip differential, you'll spin the wheels in first and get a healthy chirp in second under hard launch.

The real power comes in like a nitrous shot after 6000 rpm and stays until the car's 8000 rpm redline. Shift up at 8 grand and revs drop precisely down to the sweet spot, a hair under 6000 revs. The on-cam power is addictive and will leave you hungering for it after you dip back below that high-rev band. For those outside the Honda fold or lacking experience with an older, laggy turbocharger, keeping the revs up is the trickiest part of the driving experience. Acclimating to the high-revving requirements becomes an easy process soon enough, though it's hard to speed incognito when caning the Si requires blaring down the avenue like a BAR Honda F1 car. Rewarding? Very. Subtle? Not even close.

The featherweight first-generation Si is clearly the more nuanced of the two. Weighing just one ton, the hatchback's reflexes have an immediacy that few modern cars can match. Its unassisted steering, a bicep-builder in parking lots, settles into a pleasant firmness once the car starts moving. Unlike later Civics, which were praised for their double wishbone suspensions front and rear, this generation used a torsion-bar front suspension and a torque-tube axle with a panhard bar in the rear. The technology sounds quaint, but even though it didn't make the Civic a roadholding champ, the setup works well, endowing the Civic Si with a plucky nature and an appetite for being chucked around bends.

Hard into the hills of the Virginia countryside, the heavier '07 Civic is still surprisingly light on its feet and also shows a willingness to rotate controllably. No doubt, the LSD helps the car throttle deeper into and earlier out of a tight turn - maneuvers that would leave other front-wheel-drive competitors understeering into the grass. At the absolute limit, this from-the-factory Si still has a benign tendency to understeer, but that limit is much higher than in previous Si models.

Even better, the larger, heavier, and more powerful 2007 Civic Si has government-estimated fuel consumption figures just 1 mpg less than its first-generation counterpart achieved in 1986 (32 mpg highway for the '07 Civic Si, 33 mpg highway for the '86 Civic Si).

Bookends
With these two white Civics sitting next to each other at a roadside drive-in movie theatre, it's easy to see the similarities. No, the folded-origami three-door isn't terribly similar to the jellybean shape of today's coupe, and the new Civic is about as large as the '86 Accord, but the fundamentals - the stance, the large greenhouse, and the subtle visual tweaks - are still there. While the route between this first and most recent generations of Si may be as circuitous as some of the Appalachian Virginia roads around us, the Si sub-brand itself remains true to what it was: simple and sporting transportation, a comfortable daily commuter, and a light-on-its-feet weekend track star.

Editor's Note: Thanks to Joey Zarrella of Virginia for sharing his Civic Si hatchback with us. He's a current and past owner of several Civic Si's, and his father originally purchased this particular car new from the dealer. Zarrella held off nearly a month on a B16 VTEC conversion he planned for the car until our Motive staff had a chance to visit and sample it in its nearly original guise. He sent us photos of the car without front clip or engine later in the evening on the same day as our visit.

Our appreciation also goes out to Ben Singleton of Pennsylvania for making his matching white '07 Civic Si coupe available for our photo session.