Piranha concept car displays great seats, better harnesses
[[[[[[[[cutlines:
1/ The Pontiac Piranha is one of numerous concept cars being shown by manufacturers at the Minneapolis-St. Paul Auto Show, which runs through this weekend at the Minneapolis Convention Center.
2/ The slim-line bucket seats of the Pontiac Piranha concept car are a woven fabric, and they also exhibit 4-point safety harnesses that would be a world-class addition to any car.
3/ The 2001 Dodge Stratus is displayed at the Minneapolis show — the only show of its kind in Minnesota. It is powered by Chrysler’s over-achieving 2.7-liter V6. ]]]]]]]]]]
Auto show season is in full swing these days. The huge shows at Detroit, Los Angeles and Chicago already have been held, and the other huge U.S. show, the New York show, is still to come. But right now, this weekend, there is stilla good chance for Up North auto zealots to get to the Minneapolis Convention Center for the Minneapolis-St. Paul auto show.
Granted it’s not as large as those big ones, and it’s true that the Twin Cities show is more dealer-dominated than factory run, but there are a whole lot of neat factory cars and concept vehicles at this year’s show — more than any I can remember previously, and this is the 27th annual show put on by the Twin Cities dealers.
Spending a few hours kicking tires at an auto show is as close as most consumers can get to what test-driving auto columnists are raving about throughout the year.
If you happen to have a chance to get to the Twin Cities for the show, it runs through this weekend, with hours 10 a.m.-10 p.m. Saturday and 10 a.m.-7 p.m. Sunday.
In case you can’t, here are a couple of specialty highlights I noticed at the current show.
PIRANHA SEATS
Among an impressive array of concept cars sprinkled around the huge auditorium, one of the neatest is the Pontiac Piranha. It’s an impressive enough car, a wedgy, sleek little coupe, and there is also an accompanying cutaway model of it that shows the interior.
That includes four of the neatest car seats I’ve ever seen, and there is a working model also cordoned off from the customers, but which shows how impressive the design is.
There are several things to note about that seat. It used to be that a few companies made impressive seats while others made soft and squishy seats that bigger, heftier cars seemed to use most, and they insulated you from the feeling of being in a car, or of driving that car. As seats got better, they got to be more supportive, more form-fitting, and not as thick. Amazingly, when you want to build a firm and supportive — and safer — seat, you don’t need to make it with a foot-thick cushion and a 6-inch-thick backrest.
But the Piranha seat goes to the wall with that concept. It is a woven fabric seat, looking like nylon mesh, and that’s it. Obviously, it must be made of pretty strong stuff, if it is designed to hold a 200-plus pounder twice a day every day. We are going to accept Pontiac’s word that the seats work, that they won’t break down or get flimsy, and that they will retain their ability to support and contain the driver and riders over the lifetime of the car.
But let’s move to another area that I find extremely significant. The Piranha seats have a new, 4-point harness system.
Pardon me while I applaud.
Ever since lap belts were replaced by the 3-point lap-and-shoulder belt arrangement, I have asked why auto makers refuse to go to 4-point harnesses. The answer always has been that it’s difficult enough to get people to clasp the 3-point units on, and they’d never put on a 4-point belt.
But a few years ago, I discovered an after-market harness made by the German Schroth company. It used to make harnesses for race cars, but long since branched out to create the units to clip into regular street cars. I hooked them into my personal car, and it was simple. You bolt them onto the rear-seat anchors, then string the straps up and over the front seat backrest, where they come down fitting flush to the front of the backrests. Those straps then fasten to two belts coming out from either side of the front seat. Those lap belts fit through slots.
Now let’s consider the difference. How many times do you reach down along the left side, groping for the belt, and then the buckle itself, then you pull it up and over your front side and try to find the receptacle on the short end of the inside part of the other lap belt anchor. If you’re lucky enough to find it on first grope, you have a fighting chance of plugging it in efficiently.
In the Schroth unit I’m talking about, you climb into the seat, and you slip both arms under the two belts, with no more effort than if you were slipping into a vest with 3-foot long arm holes. Then you simply reach down and grasp two equal-length belts, and clip them together right about at belt-buckle location.
So much for the earlier criticism. Putting on the 4-point harness is actually easier than putting on the conventional 3-point harness, any day.
Ease of operation, however, is only a small part of this equation. The big key is safety. A 3-point harness is pretty safe, but a 4-point harness keeps you straight and secure in your bucket seat in the event of a frontal or rear or rollover accident.
Auto racers use 4-point harnesses, and then they go one step beyond that, with an anti-submarine belt that comes up and fastens to the bottom of the clasp to REALLY hold you firmly in place. But we aren’t all that worried about submarining down under the steering wheel in a street or highway fender-bender, at least not with the regularity of hitting a cement wall at 180 miles per hour, like they do in racing.
Still, consider those CART racers who might slide up and hit a concrete wall at 180 or even 200 miles per hour. Then they leap out and ask where their backup car is. Uninjured.
That’s the kind of safety we deserve in our autos on the streets. They don’t put airbags in race cars, because they don’t need them. The 4-point harness is more than adequate, and renders airbags as pretty much superfluous. As our accident statistics grimly point out, airbags may save some lives, but we aren’t all that sure how many, because a 3-point harness might have saved them anyway, and a 4-point harness almost surely would have saved them. Meanwhile, airbags have simply killed or injured many car occupants, either from the force of the inflation or the fact that the occupant was short and either bent over or got hit because the bag lined up poorly with their height.
The point of all this is that auto manufacturers trumpet their safety as a big selling point these days, but remember, none of them would have installed airbags if the government hadn’t forced them to bolster their “passive restraint” systems. That means we are trying to throw an air-pillow in front of those car-riders incapable or unwilling to fasten their harnesses. We feel we have to protect those who don’t want to protect themselves — it’s the American way.
So car makers have put airbags in front of us, and now they’re adding them to the sides, and in the backrests, and all over to protect and cushion car occupants from impacts.
The fact remains, I’d like to see us mandate 4-point harnesses, first and foremost. No telling how many lives they’d save. And the Pontiac Piranha concept car shows off exactly what I’m talking about.
Different companies, of course, are more serious about concept cars. Chrysler, for example, turned concepts to real-world in the cases of the Dodge Viper, Dodge Intrepid, Plymouth Prowler, and now the PT Cruiser. Audi made the TT coupe and roadster come to life as almost unchanged real cars. General Motors has a large array of concept cars at the show, including the stunning new Chevy SSR. The Pontiac Aztek is another that supposedly is going to be built.
But the Piranha? We have no idea if that is just an attention-grabber, or if the GM bean-counters will ever let it be built. Whether it is ever built or not, I’d love to see Pontiac, and the rest of GM, and the rest of the automotive world, adopt the concept of those 4-point safety harnesses.
OTHER NEW STUFF
Among other eye-catchers at the Twin Cities show:
Check out the Dodge Stratus. That may not seem so earth-shaking, but if you’re not looking for it, you might go right on past, thinking it was an Intrepid from the rear. The new Stratus is the yet-to-be-introduced 2001 car, and it bears a striking resemblance to a downsized Intrepid from the rear. The nose, however, is distinctly different, and a bit bulbous. The big news, however, makes the new Stratus my leading candidate for sleeper of the year, because it will be powered by the slick 2.7-liter Chrysler V6 engine, a dual-overhead-camshaft gem with chain-driven cams, instead of belts. It’s a precise, powerful engine, and while it is good enough to make the large Intrepid and Concorde fly, imagine what it will do with a 5-speed or AutoStick in the lighter, more compact Stratus.
While you’re at the Dodge location, follow the crowd over to the Chrysler position at the next patch, where people will constantly be surrounding the PT Cruiser. Sit in it, move the seats, fold them down, pop them out, and note all the features, for a car that is unique and will cost from $16,000-$20,000. That’s my candidate for 2001 Car of the Year, without even seeing the competition yet.
Ford is showing the new Explorer SportTrac, and the F150 Super Crew. Both are two-thirds SUV and one-third pickup truck box. Interesting. Ford also is displaying the new Escape, compact SUV that makes more sense than the jumbo versions. Note, too, the all-new Taurus, and the various models of the Focus, this year’s International Car of the Year.
Check out the Audi TT, then go through the Toyota section, where the new Celica reigns, and where the all-new MR-2 is showcased. Don’t overlook the Solara, a coupe version of the Camry. Same at the Honda place, but see if you don’t agree with me that the Accord Coupe looks racier — especially from the rear — than the Prelude. Check out the Civic Si, also, and then let your eyes pop as you check out both the affordable S2000 sports car, and the unaffordable NSX. There’s more, too, like the Jaguar S-Type sedan, the new Oldsmobile Aurora — and note how similar the Intrigue is to the old Aurora — and check the sleek new Volvo V40, and then the Saab 9-3 Viggen..
In the midst of the SUV craze, don’t look past the venerable minivans as the most reasonable means of transportation if you’ve got a family. There are all the usual candidates, but look closest at the Honda Odyssey, for all its features, and notice the new Mazda MPV, entirely changed from the old box into a competitive minivan now.
And, take one last stroll to compare how many highly-efficient, fuel-sipping products you can buy. The Focus and the Toyota Echo are the primary candidates among the mainstream vehicles, but the star of the show on that count is the Honda Insight — the already-available $20,000 car with both a 1-liter gasoline engine and an auxilliary electric motor, which kicks in for power when you step on the gas, but otherwise disengages and is recharged by the gas engine.
But those are just some of the highlights. Get to the show, and you’ll have your own.
TT Roadster completes Audi’s world-class sports car entry
[[[[[[[CUTLINES:
1/ As a spectacular view, the just-introduced Audi TT Roadster challenged the sunset-colored Bell Rock near Sedona, Arizona.
2/ The TT Roadster looks good with top up or down, and only subtleties like twin exhaust tubes differentiates the 225-horsepower version from the 180 base car.
3/ The brushed-matte finish of the aluminum interior accents is set off by the optional, thicker, amber-red leather with baseball-glove stitching.
4/ The TT Roadster has a distinct, Bauhaus-look in silhouette, with Arizona’s Courthouse Butte in the background. ]]]]]]]
Sports cars are supposed to make emotional impacts on their drivers, their passengers, and on other people who see you coming, or passing by. The Audi TT Roadster fills that bill.
I was convinced while test-driving a silver TT Roadster at the car’s introduction in the mountainous area around Phoenix, by two bits of conclusive evidence. The first was that even slathered with sunscreen against the 95-degree heat, it was apparent my wrists, forearms, neck and cheeks were being fried a lobster-colored crimson. But I wasn’t about to stop or put the top up.
The second bit of evidence came when a fellow-motoring-journalist and I pulled up to a stoplight in suburban Scottsdale and we were second in a line of three TTs. A well-tanned and very attractive woman driving a black, SL500 Mercedes roadster — with the top up — stopped in the next lane. We looked over and she asked: “How long has that car been out, and how much is it?” We explained it was just being introduced and that she could buy four of them for the price of her $135,000 Mercedes. Then we zapped away to leave her behind at the stoplight.
Audi had established itself as the competitive equals of fellow-German auto-makers BMW and Mercedes by the time it introduced its stunning new TT sports car last May. The TT, which stands for “Tourist Trophy,” was an immediate hit, but it was only a preliminary move. Last week Audi introduced the TT Roadster — a convertible version of the year-old TT Coupe — and simultaneously introduced a 225-horsepower version of both TTs as an option to the very adequate 180-horsepower TTs.
“We wanted a ‘hero car,’ a brand-defining car, and we got that with the TT,” said Len Hunt, corporate vice president and Audi of America spokesman at the roadster’s unveiling in Phoenix last week. “The launch of the TT was not just the launch of a sports car, it was the launch of a new tradition at Audi.”
The TT was a styling hit, with its advanced-retro look and high-tech features, when it came out as a 180-horsepower, front-wheel-drive coupe last May, jumping right into battle with the Porsche Boxster, Mercedes SLK, BMW Z3 in the affordable/high-performance sports-car category, which is to say stronger than a Mazda Miata, and not as overpowering as a Corvette or Porsche 911. For Up North sports-car zealots, the TT holds the extra allure of front-wheel drive.
In October, Audi added the quattro version — Audi’s phenomenal, performance-oriented all-wheel-drive system with its copyrighted lower-case “q” designation. The car fulfilled Audi’s objectives, stated by Hunt as having advanced technology, a striking design, strong performance, all while being capable of evoking strong emotion. Incidentally, the quattro version is an even stronger candidate for year-round functionality Up North.
The roadster will be available in dealerships as of the end of this month, to complete the variety of TTs. The TT Coupe with 180 horsepower and front-wheel-drive is $31,200; TT Coupe with 225 horsepower and quattro — $36,100; TT Roadster with 180 horse FWD — $33,200; and TT Roadster with 225 horses and quattro — $38,900.
Those prices include standard leather interior, with an amazing baseball-glove-stitched orange leather option on the quattros. The 180-horsepower version has 16-inch wheels, while the 225 gets standard 17-inch wheels; the 180 gets a 5-speed manual, the 225 has a 6-speed; the 180 has a single exhaust, the 225 has dual exhaust; the 180 has an easy-to-operate manual fold-down top, the 225 a standard power top. Both cars come with an improvement on one of the most impressive warranties in the business — the 3-year all-maintenance-paid warranty has been increased to 4-year, 50,000 miles, with all periodic maintenance done free.
ROADSTER ON ROAD
Taking the top off any car generally guarantees you of cowl-shake, the tendency of the body’s natural flexing to be displayed by wagging itself just a bit, most notably at the cowl area just aft of the windshield. The TT Roadster, however, is free of that vibration.
“The Roadster is not an after-thought,” said Marc Trahan, Audi’s production manager. “The Roadster was established from the start with the Coupe, and they were developed in parallel.”
That allowed Audi’s engineers to design reinforced strength into the Roadster. The door sill beams are 30 percent thicker, the sills themselves 20 percent thicker, there is an aluminum cross-member positioned just behind the seats to reinforce the whole structure, and to anchor the twin brushed-matte aluminum rollbars, which are as functional as they are stylish. Sturdier joints between the pillars and the floor assembly are further modifications meet standards from vibration analysis. The windshield frame pillars have high-strength steel inserts for added reinforcement.
“With the windshield pillars and the rollbars, the Roadster has the same level of rollover intrusion protection as the Coupe,” said Trahan, who added that even the soft top was designed with four cross-struts instead of three to eliminate any chance of wind-buffeting at high speeds with the top up.
The most evident result of all that is the complete absence of any cowl-shake or vibration. But the safety enhancements are also impressive, with that structural rigidity coupled with the TT’s 4-wheel disc brakes, an advanced antilock system, electronic brake-force distribution, electronic differential lock, full-time traction control (on the 180-horsepower versions), and a stability program that becomes available next month.
The body steel is galvanized on both sides to eliminate concern about corrosion, as well.
PERFORMANCE POWER
The same engine powers both versions of the TT. It is comparatively tiny, at 1.8 liters (actually 1,781 cc.) of displacement out of four cylinders. It is as technically advanced as any standard production engine, which allows it to feel much stronger than your basic four-banger.
It has dual overhead camshafts, with five valves per cylinder — three intake and two exhaust valves — and with a low-pressure turbocharger pumping extra life into all those valves. Displacement is measured by combining the total cylinder bore and piston stroke. The TT engine, also available in the A4 sedans and in some of Audi’s cousin, Volkswagen, has 180 horsepower that peaks at 5,500 RPMs, and 173 foot-pounds. A key to performance is what RPM point at which the torque peaks, but a marvel of the collaboration between the electronic management system and the turbo is that the maximum torque is attained at a mere 1,950 RPMs, and it remains at that peak until 4,700 RPMs.
It is little short of miraculous that Audi’s engineers took that same engine and tweaked it up to 225 horses at 5,900 revs, and increased the torque to 207 foot-pounds over a span from 2,200-5,500 RPMs. That range means that other engines may have more power at their peak, but the Audi engine gets to its peak just above idle speed and stays there until you’ve revved up toward the 6,700-RPM redline, where the horsepower peak takes over anyway.
“This is not just a computer-chip-tuned modification,” said Trahan. “The 225-horsepower engine has new pistons, a different compression ratio, different cylinder heads, different intake and exhaust manifolds, a bigger turbocharger, and two intercoolers instead of one for the turbo. The only other roadsters with all-wheel drive are the Lamborghini Diablo and the Porsche Carrera 4, both of which are far more expensive.”
With all that power, the difference between the two models in driving is interesting. The 180-horse version goes 0-60 in a quick 8-second burst, with a top speed electronically limited at 130 mph in North America. The 225-horse version quattro does 0-60 in only 6.7 seconds and has a top end of 143 mph.
When you drive the two, the 180 feels very responsive, and actually seemed quicker up to 4,000 RPMs, undoubtedly because it weighs 3,131 pounds, compared to the quattro’s 3,473. The added weight makes the 225-horse quattro feel always stable, but not as quick until that midrange, with the extra power taking firm command from 4,000-on-up.
After the brief introductory test of both Roadsters, I got the chance stay on after the introduction to spend a few days taking the 180-horsepower Roadster north to Sedona, where it was 20 degrees cooler, then winding northward on a spectacular drive through Oak Creek Canyon, and later to the Grand Canyon. We got 27 miles per gallon overall, and 32.9 mpg on strictly freeway driving, which was very impressive.
Based on preliminary feelings, the 180-horse Roadster is a superb-handling sports car capable of challenging the best of the competition, while the 225-horse version sticks to the road absolutely as if on rails, and has the power to beat most of its rivals. And, as if just for sports-car fans Up North, either version should be awesome on snow and ice.
GM unveils 2002 Bravada surprise with high-tech in-line 6
[[[[[CUTLINES:
1/ Ron Kociba stood proudly next to the 2002 Bravada introduced at the New York International Auto Show this past week with “his baby” under the hood — an all-new, dual-overhead-cam, multi-valve, in-line 6-cylinder engine with variable valve timing.
2/ The 2002 Bravada is all-new, from the frame, brakes, suspension, interior and engine. ]]]]]]
NEW YORK, N.Y.—It seemed like nothing more than a normal introduction, when General Motors chose to introduce four “all-new” trucks at the New York International Auto Show.
The executives and marketing folks took the stage and rolled them out. First, there was the new GMC Denali. Same as the Blazer, really. Then came the Denali XL, the longer version, same as the Chevy Suburban. Third out was a new Sierra pickup truck.
And then it happened. Next came a 2002 model year version of the Oldsmobile Bravada, a vehicle that once neared extinction until benevolent folks at GM decided to salvage it and give it another chance, with a new look reminscent of the Olds family two-vent front seen on the Aurora, Intrigue and even Alero.
But this Bravada is all-new from the ground up, the platform, the frame, the body, the interior, the suspension, and the engine. Especially the engine.
“This is a once-in-a-career opportunity,” said Ron Kociba, the engineer in charge of creating the all-new in-line 6-cylinder engine, “to develop a totally new engine in a totally new truck, to be built in a totally new plant in Flint.”
More on that later. First, a little background.
The automotive world is taking some exciting new turns these days, and a lot of those turns are toward high-technology developments. It costs a little to research and develop the high-tech refinements to engines, but Honda, Toyota, BMW, Mercedes, Audi, Porsche, Mazda, Nissan, Saab — you name ’em, they’ve forged on ahead, spending good money to develop advanced technology, knowing that it would bring payback in the coming years.
Trailing, but at least headed the right direction, have been Chrysler Corporation and Ford Motor Company. And General Motors? Well, with a high-skilled and plentiful crew of engineers, GM stubbornly avoided keeping up. There were a few applications of technology, such as when Cadillac went to the Northstar engine, with its dual-overhead camshaft V8, with four valves per cylinder. A smaller application of that engine was allowed to go to Oldsmobile for the Aurora, and then GM built a new 3.5-liter V6 to be built off it as well, but it, too, only goes to Oldsmobile for the Intrigue and this year as the base engine in the Aurora.
Otherwise, GM automobiles and trucks had the old-fashioned, but inexpensive, system of pushrods actuating the valvetrain from down in the block. So if you got a new car, with fancy styling, like the Grand Prix or Bonneville or Impala or Monte Carlo, you got a 39-year-old engine with pushrods — even while cars from Ford, Chrysler and every import manufacturer were well beyond merely using overhead cams, and had advanced on to multiple valves and variable valve timing.
That’s why it was so exciting to see the Bravada roll out, batting cleanup in the four-truck introduction by General Motors during the press preview days of the New York Auto Show.
ALL-NEW PLATFORM
The Bravada rides on an all-new platform. Its overall length is 10 inches longer than its predecessor, five inches wider, and five inches taller, with a wheelbase six inches greater. That extra size allows for 83 cubic feet of cargo room, up nine.
The frame has eight structural cross-members instead of the six on the previous vehicle. That adds greatly to the stiffness of the body, to say nothing of the safety and handling. All-new suspension includes a double-A-arm front and a rear arrangement with five-link geometry and air bladders electronically controlled to raise, lower and maintain a level stance regardless of road condition. Larger brakes, with discs on all four wheels, and 17-inch wheels (8 inches wide), also help the handling.
But let’s not kid ourselves. The breakthrough with the Bravada is the engine. It is in-line, replacing the hardy V6 engines so common in GM applications. Both block and cylinder head are made of cast aluminum, using the “lost-foam” technique used in the Saturn engine program, where a perfect outline of the engine is done in styrofoam, then molten aluminum is poured in, vaporizing the styrofoam and leaving aluminum in its place with precision.
Its cylinders displace 4.2 liters, with dual overhead camshafts and four valves per cylinder, and with a variable valve-timing, which allows the camshafts to adjust, overlapping when power is needed but backing off for a smooth idle.
Final figures aren’t certain, but the engine will develop 250 horsepower, and something over 250 foot-pounds of torque. Torque, remember, is the low-end pulling power needed more by trucks than cars, but needed for hard-charging starts, towing or not. As for the in-line arrangement, consider that BMW and Toyota still build exceptionally strong and smooth in-line 6s.
This is the first time GM has put an in-line 6 in a truck, the first time it has used overhead camshafts in a truck, the first time it has used multiple valves in a truck, and the first time it has used variable valve timing in a truck.
Question is, how did Kociba and his staff convince the bottom-line constables that they could limbo under the cost-effective bar and build such a progressive engine?
TIMING IS EVERYTHING
Kociba has been with General Motors for 32 years. He worked on the 3800 V6, which began life in 1961 — think about that, in this computer age — and advanced its potential with supercharged treatment. Next he got to run the 3.5-liter V6 engine, the high-tech Intrigue engine, which was the perfect launching pad to send him onward and upward when he was given a clean sheet to build the Bravada 4.2.
“We had the opportunity to build it from scratch,” Kociba said. “We had to meet several objectives. It had to be reliable, durable, affordable, and it had to have improved fuel economy and performance.”
But why an in-line engine, in this world of V6s?
“The cost of doing this on a V-type engine is prohibitive,” he said. “Think of where we’re coming from. With an in-line engine, we only have one cylinder head and one head gasket.”
Right. When Kociba says “affordable” as one key objective, he may have meant affordable to the bean-counters as much as to the customers.
“It’s all aluminum, the block and the cylinder head, with pressed-in iron liners in the cylinders,” he explained. “With the overhead cams, we could go to four valves on each cylinder, and variable valve timing on the exhaust, to give us a more aggressive cam profile.”
It not only worked, it worked so well that the new engine requires no external hang-on emission-control devices. Improved economy, emissions and power all were exponents of the slick styling. Which, of course, was why I’d long been critical of GM’s reluctance to go to such designs a decade or two before this, when the rest of the automotive world was heading that direction. I mean, if GM is the biggest U.S. car-maker, it should be a technological leader we can be proud of.
Added efficiency and durability was also gained by eliminating sparkplug wires, so separate coils at each sparkplug are used. Kociba, who simply couldn’t stop smiling as he discussed his new baby, added that the one advantage of being late to the overhead-cam, multi-valve, variable-valve-timing party, is that he was able to examine a whole world of advanced engines and pick what he wanted.
“We’re really proud of the applications we chose by picking the technology we could produce and still keep it affordable,” Kociba said.
And, of course, the future is now unlimited. This engine will go on and power midsize pickups, I would guess, and who knows what all? And the technique could certainly be applied to other engines. I’m guessing Kociba might end up in charge of redoing a few venerable old V8s in coming years.
“GM can do anything it sets its mind on,” he said.
SAAB engine concept features variable combustion ratio
Automotive engine technology seems to be leaping ahead in giant steps these days, in order to meet tightening laws for economy and ecological concerns. It has reached the point where overhead-camshafts, multiple valves and even variable valve-timing have become so routinely deployed that the line between high-tech and normal is continually blurred.
However futuristic today’s technology may seem, however, the continuation of unique ideas pushes the envelope ever-further.
Amid the high-tech surge, and the development of sophisticated hybrid engines that combine standard internal combustion engines and electric battery-made power, Swedish automakerSAAB — which is now a subsidiary of General Motors — has come up with yet another way to meet the ever-changing demands of the contemporary auto industry.
The concept is a motor with a flexible cylinder head that allows the compression-ratio of an engine to be constantly varied while it is being driven. In all other modern techniques, the valve timing or the fuel feed can be adjusted and changed, and in all of them, the engine’s compression ratio stays constant.
The compression ratio is the piston displacement volume plus the volume of the combustion chamber, divided by the volume of the combustion chamber. In simple terms, it is the amount by which the fuel-air mixture in the cylinder is compressed before being ignited.
The energy in fuel is best put to use when the compression ratio is as high as possible, but if it is too high, the engine will ping, from pre-ignition. So in conventional engines, the compression ratio is preset at a compromise level, which can tend to favor one extreme or the other, but rarely can accommodate both.
High-performance engines of years past had high numbers on their compression ratios — 10-1, or 11-1. When exhaust emissions and fuel-economy became primary, the compression ratios lowered to 8-1 or 9-1. More recent technology has allowed manufacturers to find other ways to harness emissions, and compression ratios have been able to rise again, helping create more power.
According to SAAB scientists, all other bits of technology leave the compression ratio fixed, which means that an engine may only occasionally, and by random chance, be running at optimum compression.
So SAAB has worked for nearly a decade to develop the “SAAB Variable Compression” engine, or SVC, which combines the variable compression ratio technique with lowered displacement and high supercharging pressure. All three factors are vital to the engine’s success
“We’ve been working on this concept for over eight years, and we made a four-cylinder, a six-cylinder and this five-cylinder,” said Hans Drungel, the project manager from Sweden. “We’ve run a SAAB 9.5 sedan test car with this engine with both a four-speed automatic and a five-speed manual transmission. The redline on the engine is 6,000 RPMs, which isn’t particularly high. But it has about the same power as a normally-aspirated 3.0-liter V6.”
The SVC engine is built in two segments. The monohead consists of the cylinder head with integrated cylinders, and the lower portion consists of the engine block, crankshaft, connecting rods and pistons. The monohead is built on pivots, and it can be raised or lowered, depending on the load of the engine.
When running at low load, such as cruising on the freeway, the monohead is tilted away from the lower block by hydraulic actuator, increasing the slope of its angle and lowering the engine’s compression ratio. When power is needed, you step on the gas hard and the slope of the monohead’s tilt is reduced, decreasing the volume of the combustion chamber, and thus raising compression.
SAAB’s electronic engine management system controls the variation, which is calculated to act based on engine speed, engine load and fuel quality, and in the process, it makes the compression ratio continuously variable. The same engine management system also operates a supercharger, which feeds massive doses of air into the combustion chamber off a compressor, for larger doses of boost via a compressor.
SAAB first used a 1.4-liter six-cylinder engine to develop the system, but more recently dropped it in favor of a 1.6-liter five-cylinder engine. The engine varies its compression ratio between 8-1 and 14-1, depending on engine load.
At maximum output, it turns out 225 horsepower and 224 foot-pounds of torque. Obviously, that is more power than most V6 or V8 engines in standard production, and it is incredible output for a 1.6-liter displacement.
Even more impressive than the power increase is that the SVC engine also increases fuel economy by 30 percent, and lowers emissions to meet contemporary and even future demands.
On top of that, the other most feasible concepts feature variable valve timing or alternative fuels to gasoline. The beauty of the SVC is that while it operates on a unique variable compression ratio scheme, variable valve timing could also be applied to it, and it could be programmed to burn alternative fuels.
SAAB engineers insist that the engine still is only in the concept realm, with no date to be powering cars in the showrooms. But with emission laws tightening and competing technology getting prominent reviews, it would seem likely that the SVC engine could be out within two years.
However, technology seems to be leaping ahead by large increments these days
Needs change for spring tune-up
SPRING AUTO CHECKLIST:
Putting together a checklist of maintenance rules starts with the owner’s manual of each car. It is vitally important to deal with the major maintenance intervals, such as 30,000, in order to keep new-car warranties in order. Generally the dealerships take care of that sort of work, and in many cases dealers are required to do the work.
As cars get kept longer, customers obviously want to maintain them better, and here are some key things to do during spring check-ups:
Oil changes. Some people swear by 3,000-mile oil changes, while some manufacturers are now boasting that their engines can go more than twice that far on oil because of the sealed systems and improved oils. Synthetic oils generally have a longer life span than normal oils, but cost more. It is important to change the oil filter when changing the oil, otherwise the new oil is instantly contaminated by the quart of old oil being contained in the filter. Use a good brand of oil — most top brands are pretty equal so it’s personal choice — but watch the viscosity levels closely. A 10-40, 10-50 or even 20-50 multi-viscosity is good for summer, while 5-30 or 10-30 is preferable for winter, when it’s harder for oil to flow when it’s cold.
Other fluids. Check the antifreeze level for summer cooling as well as projected winter protection, and such items as transmission fluid and brake fluid.
Diagnostic check. With computerized engine systems, it is possible for a well-equipped shop or dealership to plug into the system and check whether all settings are proper. Modern car engines don’t have ignition points, so the old-style tune-ups are a thing of the past. Spark plugs should be checked, and platinum-tipped plugs can be regapped and used for up to 100,000 miles.
Fan belts and accessory belts. It is always important to and to check the tension and condition of various accessory belts. A qualified mechanical shop will routinely check them and advise when they are sufficiently worn to require replacement. One of the most important is the timing belt on an overhead-camshaft engine; anticipated lifespan is about 60,000 miles, and failure to check and change it can lead to costly engine damage if the belt should break while driving.
Hoses. It’s important to check radiator and engine hoses for cracks or leaks. Replacement is inexpensive, especially when compared to the grief of having a family trip interrupted by an overheated engine when the radiator hose springs a leak.
Suspension. Original equipment shocks and struts are better than they used to be, but when they get worn, their effect on a car’s handling can be too subtle to notice over 30,000 miles or so. But precise steering, handling and stability can be restored by having upgraded struts or shocks installed when the original ones wear out.
Brakes. Often your car will warn you of the need for new brake pads by feeling uneven when you step on the brakes. The pads should be checked for sufficient remaining life. And replacement pads should be at least as good as original equipment, if not better.
Tires. Often overlooked, the little square-foot patch of each tire’s footprint is your car’s only contact with the road. It is the most significant piece of insurance you can invest in, and a little research is important. You can spend a lot of money for premium, long-wear, high-speed tires and be gravely disappointed in the fall when you find that their tread compound loses its flexibility and they spin far too easily in snow or on ice. Or you can spend a lot on snow tires that work very well on snow or ice, but are wobbly and hard to manage on dry pavement. There are numerous compromises, including all-season tires and some with “m & s” ratings for mud and snow. Customers must decide which compromises they are willing to make, but the difference in handling and safety control capabilities of better tires should never be compromised. Running tires at or near maximum inflation number listed on each tire might make the car ride a tiny bit harsher, but it also can provide better handling and control.
Rotating tires. This is a personal decision. With the old bias-ply tires, it made sense to rotate all five, including the spare, to get even wear. Radial tires rotate differently, and some prefer to switch them front to rear on the same sides of the car to keep them rolling in the same fashion. With front-wheel-drive cars, front tires will wear out at a much faster rate, from the weight load, the traction, and the majority of braking. Switching them front to rear will allow all four tires to wear out at the same rate.
Filters. All of ’em — starting with air filters and going directly to the fuel filter. Many driveability problems are swiftly traced to a fuel filter that hasn’t been changed at a reasonable interval.
About the Author
John Gilbert is a lifetime Minnesotan and career journalist, specializing in cars and sports during and since spending 30 years at the Minneapolis Tribune, now the Star Tribune. More recently, he has continued translating the high-tech world of autos and sharing his passionate insights as a freelance writer/photographer/broadcaster. A member of the prestigious North American Car and Truck of the Year jury since 1993. John can be heard Monday-Friday from 9-11am on 610 KDAL(www.kdal610.com) on the "John Gilbert Show," and writes a column in the Duluth Reader.
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