BMW article: The Ultimate Driving Machine

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BMW article: The Ultimate Driving Machine

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The Ultimate Driving Machine
from BMW CCA Roundel, January 1983
by Bill Howard
In the 323i Turbo, Reeves Callaway has painstakingly crafted what may be .. The Ultimate Driving Machine.
Under the hood of this BMW 3-series sedan is a 2.3 liter BMW six cylinder motor mated no, lovingly wedded to a gem of a turbocharger system by Callaway and a staff of 15 in an ultra-clean, ultra-modern shop in Old Lyme, Conn.
The result is 282 horsepower. The car will reach 60 mph in a fraction under seven seconds. It is rock steady both at 100 kilometers per hour (on its European speedometer) or at 100 miles per hour.
The initial impression, of course, is one of speed or rather of swiftness, since this is not a rumbling, 400-cubic-inch Firebird Trans Am. The feeling of speed in the turbo gradually gives way to an impression of incredible smoothness as the quality of the whole package turbocharger, installation, suspension, seats, aerodynamic aids sinks in.
Entering an interstate, Callaway accelerates hard through a 270 degree on-ramp loop. Most cars would be in the bushes. Most BMWs would be at the ragged edge. From this BMW, there isn't even a hint of tire squeal.
Out on the main road, Callaway upshifts, depresses (but doesn't floor) the accelerator and the car moves smartly away from traffic. He upshifts again and the car continues to gain speed. No buzz, no whine, no fuss, no noise.
"It's like a big hand pushing you down the road," Callaway says with a smile.
Okay, now that you know how fast it is, you're probably wondering just what Cal laway's big hand costs, how reliable it is, and why not simply drop in a 3-1iter BMW six?
If you hand Callaway a shade under $8,000 $7,850 to be exact and a 323i, you'll have a 323i Turbo by week's end. A four cylinder 320i turbo conversion is $3,650-$3,950, or $2,800-$3,000 if you're handy with a wrench and do it yourself.
Callaway Turbosystems also does 5-, 6- and 7- series BMWs, VWs, Scirocco's Porsches, Mercedes, Audis and the Toyota Celica Supra. These are cars, says Callaway, "built with an engineering and material over-statement that permits significant power increases with reliability."
The addition of a turbocharger shouldn't affect the longevity of the engine or drivetrain, provided you don't take it racing, Callaway says.
"Engine life is a function of power output," he notes. "To make a stock BMW produce horsepower, you've got to wind the daylights out of it. In a turbo, even if you're a hard driver, probably less than five percent of your total engine hours will be under positive manifold pressure ('boost'). There's such a tremendous reserve of horsepower with the turbo.
"We don't pretend to say the turbo is for everyone," Callaway says. One place it probably doesn't belong is on the racetrack for car club driving events.
"For continuous wide open throttle, you need to do more than just bolt on the turbo," he says. "We'll gladly build a turbo you can take to the racetrack. The system we sell is primarily for use on the street."
As for putting a big 3.0 or 3.3 1iter six in a 3- series sedan, Callaway says it can be done, but he recommends against it. "It's an awkward conversion . . . it makes the car quite nose-heavy . . . and it's not as fast as turbocharged 323i," he says.
"You could always drop in a Chevy small block," Callaway suggets laughingly.
Callaway is 34, has two children aged 4 and 4 months (his wife, Dale, is from Marblehead, Mass.), and majored in art at Amherst College (class of '70). They live in a house previously owned by photographer Minor White, and for several years until the past few months Callaway Turbosystems worked out of a garage at the house. Callaway spent his free time in college tinkering with cars, started a shop near Amherst, got bitten by the racing bug to the great consternation of his family and sold the shop to go racing, from 1971- 74, in Formula Vee and Super Vee. Callaway won the North Atlantic Road Racing Championship in 1972 and the U.S. National Championship in 1973 but along the way he rediscovered the racing truism: The best way to make a small fortune in racing is to start with a large one.
Moving on, he got a job at Auto Dynamics in Marblehead, Mass., as "chief chassis designer and floorsweeper" for their racing program, then worked for the Bob Bondurant driving school. When BMW signed Bondurant to run a drive-and-ride program introducing the new 320i to dealers at racetracks around the country, Callaway was one of drivers. When the program ended, BMW gave Callaway a 320i.
"I decided the 320 was really nice, but it needed about 100 more horsepower," Callaway recalls. The solution? Turbocharge it.
Car and Driver magazine road tested Callaway's turbocharged 320i, printed a favorable review in 1978, and the resulting publicity helped launch Callaway Turbosystems. "The auto magazines are quite proud of the number of cars they break," he says. "This one (the Callaway turbo 320i) managed to live."
Callaway himself drives a Volkswagen Rabbit pickup and a BMW 745i, which is the turbocharged (by BMW) 733i. It has an automatic gearbox. Callaway recommends automatic transmissions for turbo installations, and barring that, wide-ratio manual transmissions.
The anthracite gray 323i that was turbocharged for Ted Johnson of Newington, Conn., started life as a European spec BMW 323i. It was imported to the U.S. by Richard Cabell of German Imports in Richmond, Vt. The car was outfitted to the customer's tastes and air freighted into the U.S. ($1,400$1,800 "the safest way to bring it
"I decided the 320 was really nice, but it needed about 100 more horsepower."
over and well worth the money to have your car now," Callaway says). German Imports brings the car into compliance with U.S. Department of Transportation mechanical requirements (crash safety, restraints, etc.).
Callaway Turbosystems handles the Environmental Protection Agency requirements. Callaway installs a three-way catalytic converter with lambda sensor, and evaporation control canisters and hoses, then fine- tunes the timing, and checks that all the necessary connections are tight. Then it's off to the Russian Satra auto lab in New Jersey (built when the Russians planned to export cars to the U.S.) for a day of tests. The car is subjected to a highway fuel economy test, a CVS (cold vehicle start) test, and an evaporative emissions test, in which the car is sealed inside a sophisticated shed for an hour, while sensors sniff out anything (such as fuel vapors) emitted from the car.
While the evaporative emissions test sounds simple, in some ways it's the hardest of the three. Says Callaway: 'A loose hose clamp may be enough to fail the test."
If the car passes all three tests and has the needed DOT modifications it's officially certified as USA-legal.
Callaway's not complaining about the strictness of the tests, but he wonders how many mass-produced cars certified by testing a handful of prototypes are actually EPA-legal when they reach the dealers. "Of 10 cars at the dealers, not one might be able to pass," he says.
Incidentally, why send a German car to a Russian lab in the United States? Simple, Callaway says: It's about the closest to Callaway's shop and at roughly $1,000 a car, the cheapest.
Callaway Turbosystems operates out of a sparkling new shop in Old Lyme, Conn., a few miles down Interstate 95 from the Navy submarine base in Groton, Conn. In the background is the dull roar of the highway, but the access road to
Callaway's shop is so heavily forested that Callaway warns visitors to watch out for deer (one came down to look at the 323 the day of my visit).
A grassy lawn slopes down to the front of the shop. It has a clean, modern design. The facade is covered with shimmering gray aluminum panels and reflective glass windows ("I told the architect to make it look like a Sony clock radio, Callaway quips). The building windows mirror the progress of the cars as customers drive into the parking lot, alternately lengthening and shortening the reflections.
Inside, there's 10,000 square feet of office and shop space, a far cry from the 1,700 foot garage when Callaway and his staff worked literally out of his house and garage nearby.
The shop floor glistens, a combination of newness and attention to cleanliness. On this crisp fall day, in addition to Ted Johnson's 323i, there is a blue 530i from Massachusetts, a white 320i from New York another white 320i from Florida, and an Audi coupe from Connecticut. A Porsche 928 makes a brief appearance.
Callaway says the company converts about 200 cars per year in the shop, with five or six times that many sold through the mail.
Off to the side are rooms for electronics research, dynamometer testing, pattern-making, and order handling, and shipping. At the very back are floor-to-ceiling racks of goodies: turbocharger units, manifold pipes, gauges, stainless steel hoses and fittings. State-of-the-art metal-working machines, including a computerized Japanese lathe and milling machine, turn out 85 percent of the parts that go into Callaway turbo systems.
Tony Vastola, Callaway's pattern maker, is a graduate of the respected Rhode Island School of Design. His patterns, such as the exhaust manifold designs hard-carved in mahogany, are works of art in themselves. Electrical engineer Charlie Kuehnl is at work on a fourth-generation fuel enrichment,' detonation control device to succeed the sophisticated Microfueler, a black box jammed with microchips
The conversion process to turn a 323i into a turbo 323i is "not just a bolt-on operation . . . it's done from the ground up," Callaway says. The whole engine is reconfigured just for the turbo.
The workmanship is nothing short of first-rate. Everything in a Callaway system is designed not only to work, but to be aesthetically pleasing to the eye. If engine compartments could be canvasses, a Callaway turbo installation is on the order of a Picasso.
The displacement is increased slightly while compression is lowered from 9 . 5 :1 to 8 . 2 :1 . One of the significant advances of turbo technology is to have compression ratios in the eights, rather than sevens or sixes, Callaway says, which makes the switchover from manifold vacuum to boost less jerky. Early Porsche turbos, with compression ratios in the sixes, he says, were "an absolute knife
The 323i motor gets new Mahle forged turbo pistons, piston rings, engine bearings and a new head gasket. The cylinder head is modified slightly with material ground out of the combustion chamber. The crankshaft is balanced and new bearings are installed. Connecting rods remain stock, as do the camshaft and valve train. The distributor has both advance and retard and ignition wires are heat resistant silicone.
A heavy-duty radiator and lowertemperature thermostat are installed, along with an oil cooler that kicks in at 180 degrees (optional on some other Callaway installations, but always highly recommended, he says).
The individual runner exhaust manifold is made of NiResist, a high-nickle, high-temperature ductile cast iron. The manifold feeds exhaust gas into a Japanese- made I.H.I. turbocharger located just below the exhaust manifold, at knee level. The "low blow" installation keeps the turbo heat away from delicate engine components, but efficiently close to the exhaust manifold.
According to Callaway, all major turbocharger manufacturers Garrett, Rajay, K.K.K., Rotomaster and I.H.I. make first-rate products. The I.H.I. stands out because of its compact size and efficient compressor design.
"The I.H.I. has probably the most efficient compressor design in the world. It gets from 25,000 rpm to 200,000 rpm (operating speed) at least 50 percent faster than any other unit," he says. "When you press the pedal, you get power right away. Lag is minimal."
A wastegate that blows excess exhaust gas off to a Callaway designed, free-flow, stainless-steel exhaust system is set at 10 psi. (An adjustable 6-15 psi boost pressure gauge is optional, and definitely not for the novice.)
On the compressor side of the turbo system, air is routed from the air cleaner into the compressor, then to an intercooler a radiator to cool air just behind the right front headlights. Although it's one of the most expensive parts of the turbo installation and standard only on the 323i and Porsche 928 turbo systems, Callaway says the cooling effect of the intercooler can increase power by a whopping 20 percent.
From the intercooler, air is ducted into the intake manifold. A "Microfueler" squirts extra fuel into the intake manifold during boost conditions. This third-generation fuelenrichment device was developed to overcome a limitation in the Bosch fuel-injection systems: the Bosch systems rely on a hinged flip in the intake-air stream to indirectly control fuel flow to the injectors. The more air rushes through the system, the more the flap bends and the more fuel is ordered through the injectors. Unfortunately, the flap runs out of travel during turbocharger boost (positive manifold pressure) and there's no way to order extra fuel through the injectors. The Microfueler steps in and triggers an extra Bosch fuel injector in the intake manifold to supply the needed fuel.
Callaway says there was a steep learning curve" between the three generations of fuel enrichment devices. The Microfueler, a black box chock full of integrated circuits, is by far the most sophisticated. It succeeded the (:allaway Turbofueler, which in turn succeeded a device he jokingly refers to as "the equivalent of waving a garden hose at a stream of air."
When the intercooler is installed, there's no need for water injection (another method of cooling the air entering the engine). "From a convenience standpoint, the intercooler is nice because it eliminates one of the few customer serviceable items (water injection) we otherwise would depend on," Callaway says.
The driveline in the 323i turbo is untouched, largely because the power even 282 horsepower comes on so smoothly.
"The turbo is gentle on the driveline. This is not a hemi 'Cuda," he notes.
The 323i's brake system also remains stock. The 323i has vented disk brakes in front, unvented disk brakes in back.
The suspension is all BBS: BBS progressive rate springs and BBSdesigned Bilstein shock absorbers. Four 1 95/50-VR15 "plus two" Phoenix Stahlflex tires (Callaway's preference in the high-performancetire spectrum) ride on 1 5-inch BBS wheels, six inches wide in front, seven in back. The effect is to lower the car 11/2 inches, not quite lowrider territory, but easily more aggressive than stock. There are front and rear sway bars, stock with the car.
Callaway admits to slight reservations about the suspension. On glass smooth roads, it's superb. But on country roads with potholes, dips, bumps, and frost heaves, the suspension is stiff, occasionally choppy. Your fillings are never in danger, but it's certainly an "enthusiast's" suspension.
The exterior package is finished off with Callaway Turbosystems decals in the back-seat side windows and front and rear air dams. At the speeds this car can attain, the air dams are truly a help.
Inside, there are Recaro seats, a comfortable, leather-wrapped steering wheel (connected to power- assisted rack and pinion steering, a true delight), and three VDO gauges nestled in the console: oil pressure, vacuum/boost (with Callaway's name tastefully printed on the face), and oil temperature. If you're one to constantly monitor gauges, you might wish they were closer to the line of sight and angled toward the driver. The gearshift is five speeds. Fifth is overdrive. An Alpine stereo (Callaway has no strong preferences in stereo systems) and an Escort thoughtfully tucked in the glovebox complete the interior.
The car starts instantly when cold, and does so a half-dozen other times, whether the engine is cold or quite warm. When starting off slightly more throttle pressure is necessary to keep the car from stalling compared to a stock 320i but except for the 0-2 mph range, the advantage in performance, handling and smoothness is all in Callaway's court.
Because the turbocharger gauge is out of the way, it's hard to tell when exactly boost comes on. Suffice it to say that it does. In the lower gears, the rev line comes up quickly and the driver must pay attention, because the turbocharger itself muffles some of the exhaust noise. Callaway recommends shifting early and letting the car's incredible torque bring the car to speed.
Country roads are a delight, perhaps a wee bit choppy because of the suspension. Winding, two-lane, 50 mph roadways with quartermile straights for passing every now and then bring a smile to the eyes. Imagine a stock 320i in this situation: You tailgate the slowpoke ahead of you, downshift to third, wait for the oncoming lane to clear, jam the throttle to the floor, and at a pace the car ordains, not you accelerate to 65-75 before oncoming traffic forces you back in lane.
Compare that with the 323i turbo: Lay back so you don't make the driver ahead feel claustrophobic, stay in fourth (fifth if you're sporting about this), wait for the oncoming lane to clear, then urge the gas pedal to, oh, say, four-fifths wide open throttle. A quiet, sweet hum passes through the firewall as the turbo winds up and up and up. It's the sensation of a jet on takeoff, of power that's gently but firmly there and never wants to quit. In a few brief seconds you're closing in on 80, perhaps 90 mph (or its metric equivalent in this car), the slowpoke ahead of you is well astern, and you ease back into your own lane. No muss, no fuss, no nervous worries about whether the speck on the horizon is an oncoming car or low-flying crow.
Then there's the interstate. At this juncture in auto road tests, it's customary to report how some cowboy in a Corvette or 911 SC challenged the honor of your Q-ship and how you blew him away, leaving the Corvette Club befuddled, sadder and a bit wiser. Sorry didn't happen. On this day the Connecticut turnpike was the usual mixture of Mazdas, Citations and 18-wheelers. The best I can report is an upholstery cleaning truck doing highway speed-plus in the right hand lane as I entered the beginning of the on-ramp merge area doing 40. As far as I can determine, we were abreast at the beginning of that 200-yard strip and he was a car length behind halfway down the strip. Take that, upholstery truck!
Top speed was not observed, because of the crowded highways and respect for the car's owner (dld you know we borrowed it, Ted?), but the speedo needle did point, twice, a tad beyond 190 kph. 100 kph equals 62 mph, so we're talking somewhere on the high side of 115 mph.
Breaking free of one interstate wolfpack and attacking the next takes only a few seconds. However, the competition is so clearly overmatched that the fun wears off rapidly and that first impression, of unlimited acceleration, gives way to a reminder of how smooth and complete the car is. Even on Connecticut's mediocre highways, 55 mph and up is quick enough to soften the suspension chop that is so evident on 30 mph roads.
Gas mileage, obviously, is a factor of how much the driver tinkers with the gas pedal. But Callaway says it should easily fall in the 20-30 mpg range.
To compare the 323i turbo to other BMWs and BMW turbos, Callaway provided these figures: a stock 320i produces about 98 horsepower, 105 for the 1977-79 2.0 Iiter cars. Bolt on Callaway's turbo and you've got 180 and 195 horsepower, respectively. Add the intercooler (in place of the water injection) and you get a few more. The 2.3 liter six-cylinder engine (part of the 528e engine family) puts out 140 horsepower in stock trim, 282 horsepower with the turbocharger and intercooler.
"What impresses me most about the 323 (turbo) is what it represents as a total package," Callaway says. "It's not a buzzbox anymore. There's no four-cylinder engine buzz, no second and third order harmonic vibration, there's torque at the low end where you need it."
It's the ultimate refinement of the Ultimate Driving Machine.
Callaway 323 turbo engine:
1. Individual runner exhaust manifold funnels

exhaust gas to turbine side of turbocharger
2. Air is ducted from air cooler to compressor side

of turbocharger
3. Turbine, spun by exhaust gases, reaches 200,000

rpm and spins compressor.
4. Wastegate ducts / pressure in excess of l0 psi to

exhaust system to prevent excess boost pressure.
5. Compressor side of turbo compresses air ducted

from air cleaner to as much as 10 psi. Air goes to intercooler.
6. Intercooler cools compressed air from turbo,

helps increase engine power as much as 20%. Air goes to intake pipe.
7. Silicone-rubber sleeve damps vibration between

engine and stationary air cooler
8. Intake pipe ducts cooled compressed air into

intake manifold. (Microfueler, not shown adds fuel into airstrearn during boost.)
9. Turbosport ignition has advance, retard, heat- resistant wiring
How a turbo works
When the driver pushes down on the gas pedal, more fuel and air is burned and more exhaust gas is formed. The additional gas, ducted through the exhaust manifold to the turbocharger, makes the turbine spin faster, from 25,000 rpm while "loafing" to 200,000 rpm working speed. The turbine is connected by a shaft to another turbine on the compressor side of the turbocharger. Air from the air cleaner is sucked into the compressor and compressed to as much as 10 psi (about 170 units of air compressed into the space of 100 uncompressed units). The compressed air goes to the intercooler where it's cooled, just like water in a radiator. (Cool air has more potential energy, carries less risk of detonation.)
From the intercooler, the compressed, cooled air is ducted to the intake manifold, where it goes into the cylinders and is burned along with injected fuel. Extra fuel is also injected into the intake manifold via Callaway Microfueler to provide correct fuel-air ratio and prevent detonation.
Pressured intake charge yields more power and more exhaust gas, so turbine spins faster, forces still more air through compressor until 10 psi boost limit is reached. Then wastegate opens and excess exhaust gas is routed straight into exhaust, rather than through turbine.
This was a long but very interesting read, did you enjoy it too ?
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