Monday, December 7, 2009

The Enemy of Weight

Review of the 2012 Bridget Roadster from United States Motors
by Dennis Mac Lugage
Car & Track Trends Magazine
May 2012

Aircraft and car designer William Stout is reputed to have said that the key to building a good performing vehicle was to "Simplicate and add lightness" although some say it was ol' H. Ford hisself that put the phrase into Mr. Bill's ear. Whether it was W.S or H.F that said it they were both pikers compared to loquacious Texas zillionaire Sorenson "Sonny" Sanders. Sanders is the genius/lunatic behind the much anticipated Bridget Roadster which is one of the lightest, simplest, and utterly sweetest four wheeled conveyances to roll down the pike in many an over-regulated moon. And if weight is truly the enemy then Miss Bridget has opened up a Lone Star State sized can of whup-ass on it.

Not only is the Bridget light, simple and sweet but it is also something that would have warmed Henry's cockles which is to say cheap. Not cheap in the usual automotive sense of cheesy, tinny, or fragile but rather entirely lacking in any cost or weight increasing frippery that does not directly contribute to the goal of traditional sports car driving enjoyment. The list price is $15,000 which is beyond astonishing in an age when putative econo mobiles are pushing smartly past 20,000 bucks. It is in fact actually cheaper in relative terms than its spiritual forebears such as the late 50s/early 60s bug-eyed Sprites and MG Midgets with not a little of the jewel-like mid-60s Honda SM 600 thrown in. Sanders and his design team have pushed the concepts of light simple and cheap to the outer boundaries of possibility in a time of massively overbearing automotive regulation. Amazingly the Bridget has been designed, certified and is in production on a budget of approximately 100 million dollars. That may be a whacking load of dough for plebes like us but it's chump change in the creating a car company from scratch game.

Speaking of the gummint Sanders is eager to have us know that, "The Bridget has been designed, tested, and manufactured without a dime of any government money, federal, state, county, local or otherwise. And our operation near Houston has received no city tax breaks whatever for establishing our assembly facility. Not only that but the entire company is accountable to no one but me. No stockholders, no dodgy IPO scams, and no milking of the great green federal money machine. It's all my baby and I'm beholdin' to not a living soul--except for my customers of course."

How how how has it been done? Let Sanders do more of what he does best which is to hold forth at length. "We started this project with several targets that had to be met. First it had to be a two-seat roadster of conventional mechanical architecture and proper sports car looks and handling. Second it had to weigh no more than 1600 pounds. The third target was a horsepower rating of 70 and a torque rating of 100 pound-feet . The last and by far overarching target was that this was to be accomplished at the absolute minimum weight, simplicity and cost possible. Those four obsessions resulted in the Bridget and we are damned proud of our work."

To call those targets obsessions is to rather severly understate the case. Consider the weight. U.S.M. has added a great walloping pile of lightness. At 1600lbs. the Bridget is an astonishing 700 pounds lighter than even the recently introduced "lightweight" Mazda MX5. It is a smaller vehicle as might be imagined but it still holds two reasonably sized occupants and has a useful if diminutive trunk. Quite a trick with a wheelbase of 80 inches, a width of 55 inches and an overall length of only 130 inches. It is not a roomy cabin to be sure so if you are, er, width challenged, Miz Bridget will be a squeeze. So be it. A better reason for going on a diet is difficult to imagine. Neither will NBA centers be buying the Bridget. Tall drinks of water over about 6 feet two inches will have a tough time folding up in the cockpit and ducking under the canvas top. I'm not so "challenged" but if I was then if height reduction surgery were any kind of an option I'd be considering it. Sad to say but if you shop exclusively at Big and Tall outlets then you are out of luck. My sympathies.

The Bridget is simple but very deceptively so. What it is in fact is ruthlessly optimized which is not mentioned specifically in Sander's remarks above but is the key to the whole project. Most manufacturers claim that their sundry products are throroughly optimized but current evidence is unconvincing. Virtually every vehicle has ample reserves of strength in both powerplant and chassis design with a view to future upgrades. The very fact that hotrodders can slide a Chevy V8 into the engine compartment of a Miata without it promptly collapsing to the ground is ample proof of this. This tendency is understandable from a corporate cost-control standpoint which makes the tale of the Bridget's design genesis all the more unusual. U.S.M not only set the goals and targets for the design to meet but also used those targets as absolute upper limits in terms of power and strength.

For instance the powerplant is precisely the size and weight to produce the power desired and no larger or heavier than absolutely necessary in any of the components required to do the job, period. U.S.M decided that the smallest lightest, and simplest, unit that would meet the case would be a 1.4L inline four cylinder engine that uses, if you can believe it, two valves per cylinder operated by a single in block camshaft with pushrods. Yes pushrods. How bizarrely retro you might think but consider that the Corvette ZR1's 650 plus horsepower is generated by a pushrod engine and few quibble with the 'vette's go-fast credentials in the supercar wars. In point of fact the Bridget's engine is essentially a quarter scale small block chevy which again might seem disturbingly retro but if there is an engine architecture which has had more development money and hours (countless millions) spent on it I am entirely unaware of such.

All of the engines internals right down to the bearings are sized to support the power produced and no more except for small margins in the interest of safety and service life. The all alloy engine weighs less than two hundred pounds ready for action and produces power in an easy going undramatic manner. 90% of peak torque is available from a mere 1000 revs up to the mild 5000 r.p.m. electronically limited redline. With such a broad band of grunt a five speed transmission is very nearly overkill but the Bridget makes do marvelously with its feathery Tremec 100 unit. The trans is yet another component that like most on this vehicle have rather the aspect of scale models of various bits. The driveshaft meaures only 1.5" in diameter and the solid, yes solid, alloy rear axle, which looks like it might have formerly resided under a golf cart, barely tips the scale at 70lbs with its half inch axle shafts and six inch ring gear. In fact U.S.M. claims that the Bridget's entire drivetrain--engine, suspension, steering, brakes and wheels dress out at under 500 pounds. Remarkable.

The engine really needs some respectful analysis. Its design runs so counter to practically everything else in an age of hyper-boosted, direct-injected, variable valve timed mighty-mites that it seems like something from another age. In a way it is with its pushrod actuated two valves per cylinder design but its very reason for existence is to supply uber flexible broad banded grunt and not howling high-rev horsepower.

To hear U.S.M. declare it the motor is the simplest lightest way to the desired torque/power characteristics that is possible without using materials any more exotic than steel and aluminum. It is not particularly highly tuned, even for a seemingly stone-axe evocation of a 350 Chevy small block. Its limited valve area, undersquare bore/stroke relationship, and mild cam timing deliver a hundred pound/feet of torque across a band that would do a steam engine proud and the resultant 70 horsepower at 5000rpm is merely a mathematical construct that explains the car's 102mph top speed. It does have a fairly high, 10.5 to 1, compression ratio which is enabled by the alloy head and substantially aids in torque production. The rev limit of 5000 seems absurdly low in this day and age but that fact aids in keeping the engine internals only as stout as they absolutely need to be whilst meeting the performance goals.

This quarter-midget small block has an exhaust thrum that has a nice snap crackle to it but a throaty growl from its small tail pipe is not part of the buy-in. It does have a bit of the character of vintage flathead mills due to its low-rev high torque design which suits me just fine. So while it certainly does not sound like a Viper neither is it saddled with the tinny blat of import tuner specials.

Engines do not produce horsepower. They only produce twist (torque) at the crankshaft and horsepower is nothing but that torque multiplied by a frequency of application (rpm) factor. A 1.4L engine with a peak torque of 100lb/ft is not remarkable. An un-boosted 1.4L mill with that level of torque spread across nearly its entire operating range is extremely rare. Actually non-existent as far as I know--at least in the production automotive world. Equally remarkable is the fact that very few of this vehicle's drivetrain pieces fell off someone's parts shelf somewhere.

The engine and the Tremec trans illustrate perfectly the genesis of so many of the Bridget's bespoke components. Design and fabrication help was solicited from manufacturers entirely familiar to the hot rodding community such as Flaming River, Trick Flow, Currie, Tremec, Be-Cool, Lunati, Wilwood, Zoom, etc. etc. U.S.M. was interested in re-inventing the process and not the wheel although ironically the wheels are one of the few non-custom components employed. They are good ol' American Racing Torq-Thrusts shod with Dunlop 185/60/14 all-season rubber which provide hot rod character and plenty, way plenty, of grip.

This is actually quite a lot of rubber on the ground for a car this light but U.S.M. decided on the size for the purposes of wide availability, low cost, and adequate pot hole protection which is a particular bugaboo of super low profile rubber. There are even a number of choices in reasonably priced winter rubber in this size which is an big additional advantage, especially for a light car without a limited slip differential.

The Bridget's body/chassis is alleged to be just strong and stiff enough to do the job, and to meet crash specs. It's likely bendy compared to many hyper stiff modern designs but U.S.M reasons that it is a car and not a block of granite so it's supposedly precisely stiff enough to assure decent handling without a superflous ounce of weight. There is in effect little or no expansion room in the whole design which is intentional. Quoth Sanders, "We have decided that the Bridget will never weigh more or develop more power than it does now nor will it ever have increased handling prowess which would require any weight increase--period. It's right where we want it in every regard and any changes will be confined to correcting any service problems and improving component reliability. Not only that but the price will never increase faster than the rate of inflation nor will it ever be affected by the creeping gadgetitess that has made so much modern automotive product tantamount to rolling arcade games."

Big talk for an automotive CEO and very odd talk indeed for such to aver that his company's product will never be any "better" than it is right now. Revolutionary talk you might say, even heretical, but if so then we're officially turning ourselves in to the Inquisition for whatever punishment comes our way as long as we can drive to the trial on a winding road in a Bridget.

Let the heresy continue. The Bridget has taken the supposed vice of "de-contenting" and hammer-forged it into a signal virtue. Look in vain for digital dashes, navigation screens, Blue Tooth everything, On-Star, back-up cameras, GPS, hands-off this and voice-controlled that. Instead observe with intense retro-grouch satisfaction the simple six mechanical gauge dash pod (tach, speedo, fuel, oil pressure, water temp, and charge) and the two speaker radio with an actual click on/off volume knob. There is not even an MP3 plug to be found. Leave the pod music at home lest you miss a second of the sweet sounds of Miss B.

Nowhere is an idiot light to be found so pay attention or pay the price. The windows roll up manually, the mirrors adjust by hand, and no trace of hydraulics or electrics sully the simple top mechanism. The steering column has a turn signal lever and that's it. The lights are controlled by a pull-out dash knob and yes, you guessed it, and actual floor switch for the high-beams. Simple but bloody damned good simple.

Continuing in the retro-revolutionary vein is the solid aluminum rear axle, developed and manufactured by Currie Enterprises, which is supended soley by two composite "leaf" springs and damped by two simple easily serviceable shocks. The leaves may look simple but they are precisely tailored units that have a spiral wound outer layer that renders them compliant vertically but torsionally stiff. Stiff enough torsionally in fact to dispense with the need for a rear anti-roll bar. In fact two leaf springs constitute the entirety of the rear suspension which we judge is only made possible by the modest power level of the engine. It hardly requires an excess of sophistication to handle 100lb/ft of torque on a vehicle with no more than about four inches of rear wheel travel. Final analysis? Simple, light, just right, and so very Bridgetesque.

Disk brakes grace each corner with seemingly inadequate 8 inch solid rotors all round with small single piston calipers up front and even smaller ones in the rear. They're enough though and they do not even sport power assist but, as our press outing revealed, even relatively delicate distaff gams have enough force to reel in the Bridget's speed smartly. Look in vain for anti-lock gear or gadgetry of more recent vintage such as brake force distribution or traction control. No matter 'cuz the brakes are firm, easily modulated and a snap to hold at impending lockup.

The bitty rack & pinion is, natch, just big enough, and is also without power assist which considering the car's weight is not surprising. It's also perfectly weighted, endlessly communicative, and un-twitchy even when the car works its way toward the ton. The front suspension is where some of that de-contenting of the whole vehicle really pays off by allowing funds to be spent on a proper all alloy wishbone setup the equal of anything on the road. Even the aluminum radiator is just big enough to cool the engine in typical Texas summertime heat. The thing would probably not make a good paperweight. Repeat after me--light, simple, cheap.

The car's styling is properly slab-sided retro but the headlights are faired smoothly into the fenders rather than planted on the hood ala the Bugeyed Sprite. Simple marker, tail, and backup lights adorn the corners and the lights are not, heaven forfend, subject to any delayed turnoff trickery. Of note are three light, simple (natch) alloy rear view mirrors that are hand adjusted. And they stay that way with no flimsy flip-flopping around evident. This only further illustrates the Bridget's reliance on minimal componentry which is solidly, thoughtfully, and lightly built. The Bridget may be inexpensive but not one thing on the vehicle feels remotely "cheap".

The body is decidedly styled in homage to its ancestors, san bumpers of course, and there is even a hint of rounded tail-fin at the back housing the tail light assemblies. The front end is resolutely smiley-faced with little trace of current, regrettably busy in many cases, design flavor. Overhangs are short and trunk space minimal, pack light, but the front fender bulges and rear mini-fins crisply define the corners visually for the driver so slicing and dicing in tight confines is a snap. Bridget may no easier to park than a Smart Car, iMiev, or Toyota IQ but it will have plenty of room to swing wide the doors in most lot slots.

The chassis offer some interesting touches. The doors have twin latches to aid in torsional stiffness and the slim driveshaft tunnel sports a couple of alloy braces along the bottom to further same. The chassis mounts the suspension points directly and eschews sub-frames which must save quite a bit of weight. Most of the seams in the chassis are fully welded thereby adding stiffness at the cost of a few bucks but with the result of adding substantial beef with little weight. Bridget employs a slim eight gallon alloy fuel tank, fuel cell actually, that in the manner it bolts to the chassis betwixt the rear axle and rear cabin wall also contributes to torsional stiffness. Clever sods these Texans.

The interior is in perfect alignment with the stated mission. Miz Bridget has only one interior to choose from and it is perfectly in keeping with the car's theme of light and "cheap". A single color predominates, call it Stealth Gray, with a few chrome accents to break things up a bit--air vent and gauge bezels, door handles and window cranks. Thinnish but sturdy looking carpet adorns the small floor area and is positioned well clear of potential pedal snagging. The small, non-adjustable, steering wheel is nubbly plastic, properly thick, and three spokes offer proper two, five, eight, and ten hand positioning. I note that care was taken to ensure the correct spacing and height for arm draped on the window sill cruising behavior.

Seats are somewhat thinly padded yet comfy enough but lightly bolstered which is fairly irrelevant since one sits confined between the door and driveshaft tunnel. Nothing fancy, at all, in the cloth upholstery but it looks reasonably nice if not flashy and gets the job of holding the driver comfortably in place whilst negotiating the twisties. On the whole things are fairly monocromatic but a driver is supposed to be paying more attention to what's going on outside the vehicle than inside it. Not only is the Bridget decontented but it is de-blinged as well. Decidely not for the flash and trash crowd but dear Bridget is hardly aimed at that lot.

The shifter sits short and high, aided by a nicely padded arm rest on the driveshaft tunnel, and is in light snicky-snacky harmony with the delicacy of the other controls. The eight inch Zoom designed clutch take up is perfectly gradual, no bear-traps needed here to efficiently pass on the mini motors twist to the rest of the feather light drivetrain. The pint-sized engine/flywheel/trans combo has so little rotating mass that shifts never lag behind even gunfighter arms. Miz Bridget is like the perfect sugar cookie, plain but ineffably tasty.

Heating and ventilation are exemplary with copious easily directed airflow to windshield, torso, and especially tootsies which promises to make cool weather top-down cruising enjoyable. According to Sanders U.S.M would have liked to include AC in the package but at a weight penalty of at least 75 pounds and a tab of a thousand bucks it didn't make the cut. The considerable air volume possible through the vents should make top up warm weather driving at least tolerable. Ask me it's a small price to pay but then again I live in Michigan not Texas or Arizona. I don't expect the lack of air-conditioning to be a deal breaker for the intended market of stroker cap and string-back glove wearing retro roadster nuts.

Bridget has a spare no-nonsense cabin to be sure but SUV seating height is not part of the equation. This is by-god sports car people. It sits low, it handles sublimely, it costs squat, and it looks good. Everything else is a piffling detail. As the saying goes just shut up and drive.

Lastly it should be noted that the Bridget is sold with no options save body color. No as in none. Not a one and none are intended from the factory although the aftermarket is sure to respond to the challenge straightaway.

All right enough blathering on about componentry, entertaining as that might be, and on to the car's performance. In a word, sterling. Although you won't be spending much time at the drag strip you'll always be hunting for roads that curve and swoop. The press rollout for the Bridget was in the little town of Kerrville, Texas which is a main gateway to the beauties and the sweet sports car friendly roads of the Texas Hill Country. No less than ten Bridgets, in assorted colors but otherwise identical, were provided and amazingly no one smashed one up although not from lack of trying. The cars relative lack of power and exquisite handling prowess invite diving ever deeper into a turn then nailing the throttle before the apex while trying to deal with the ache of a huge permanent smile etched on one's face.

This particular chunk of the Hill Country has sections with an almost alpine feel to them. This being high spring some of the higher "peaks" sheltered pretty little patches of lupine remindful more of the Rockies than central Texas. At least I think they were lupines considering I was able to only catch a furtive glimpse or two out of the corner of my eye while clipping apexes. Purty pastoral panoramas are swell but the work of dissecting some of the best sports car roads we've ever encountered allowed little distraction.

The Bridget is not darty and nervous despite its slight poundage but it is effortless. As stated above the steering is perfectly weighted and communicative without a hint of twitchiness. The chassis doesn't shake or rattle and it scarcely rolls at all which is remarkable considering the lack of a rear bar. The merest hint of understeer obtains on corner entry but a bit of throttle squirts the car through corners, especially the tight twisties of the Hill Country, with an unlikely mix of delicacy and authority. The emphasis is on driving quickly and efficiently and not terrorizing the countryside with powerslides and artillery loud exhaust roar. Driving the Bridget is not work of any sort. All control efforts, shifter included, are pleasingly un-heavy and well matched to each other--even the accelerator pedal. It is in toto surpassingly easy to drive--light, agile, responsive, endlessly fun and engaging.

The ride is certainly sports car firm but not remotely punishing and the flyweight suspension allows a decent measure of rough road holding compliance. Out on the interstate the Bridget hardly encases one in a tomb like silence but it's not at all bothersome, top up or down. In commuting duties the engine's broad band of grunt means no frantic shifter flailing to keep up with traffic while at speed the relatively tall rear axle ratio of 3.25 keeps the mechanical busyness in check. In other words it's all just right--Bridget right.

Oh yeah perhaps you're wondering what kind of mileage this gem attains. The D.O.T rating is 45mpg combined. A couple of dozen lead-footed scribes were unable to break below 40mpg during the press rollout and we do not doubt that with a bit of hypermiling the far side of 50mpg is possible out on the slab. Ironically great mileage may be the one thing that was not a planned target during the car's gestation. The U.S.M. team knew that a reasonably efficient low powered engine in a very light vehicle was going to be inherently economical so they simply accepted what they got and worried further not.

You will of course go much faster in virtually any high performance product from the likes of Audi, BMW, Porsche, or heck for that matter Kia and Hyundai but you will not have any more fun and for the price of some of those marques' products you can have a Bridget for every day of the week. Unlike our usual review you'll notice little mention of performance specifications. Oh we have the usual info and graphs appended but you won't, and I damn sure don't, care what they say, at all. If ever a mechanical device was greater than the sum of its parts the Bridget is it and talk of 0-60 times, cornering forces, braking distances, etc. is benignly irrelevant to the consummately enjoyable package that is Miz Bridget.

Much is made of some vehicles' abilities to almost become one with its driver but the Bridget has to be the little queen of them all. You do not get in the Bridget so much as put it on and then allow your toes and fingertips to interpret the cut, thrust, and curve of the pavement. My capability in the area of laudatory panegyrics is inadequate to the task I fear. Basically I lurve the Bridget and if you don't feel the same way then you have my infinite pity.

I suspect that a viciously fanatical following will spring up following the beginning of sales which is as you read this. I further offer the prediction that the Bridget will inevitably spawn a single marque race series.

Regarding whether or not you'll be able to buy a Bridget in a year or three fear not for Sonny Sanders has very deep pockets and the patience to let the Bridget find its market even if it takes a sizable chunk of time to do so. If the raves of usually testosterone addled and horsepower addicted professional automotive journalists are to be credited then Mr. Sonny's wait is already over. The press worthies assembled for the rollout, who normally yawn at any vehicle less powerful than a Saturn V rocket, were practically gobbling with enthusiasm which is undoubtedly music to Mr. Sander's entrepreneurial ears. On a fun per dollar basis the adorable Miz Bridget may be the deal of the new century--or hell any century for that matter. Get in line. Get one. Make an appointment with your doctor to treat RGS (Repetitive Grin Syndrome). Enjoy.

And oh yeah. Sonny Sanders for President!


Blogger Largo said...

I've been teaching my eight year old son about physics, oscillation (and timing), and the ICE. Interesting comments you had lately about such current technical advances as igniting the air-fuel mixture with laser, and electro-mechanical (and pneumatic) means of varying the timing of ignition.

It's great to be able to tell him how this in not just century old technology, but that research has been ongoing still that time, and is ongoing still. I would have had no idea about the particulars of recent development (and would have had nothing to share with him about it) if I had not discovered your blog.

I'm glad to see a new comment from you. Receive my encouragement and thanks!

- Largo.

December 12, 2009 at 5:30 AM  

Post a Comment

Subscribe to Post Comments [Atom]

<< Home