Date: Wed, 11 Jan 95 23:11:51 CST
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Joel Walker <JWALKER@ua1vm.ua.edu>
Subject: another road test: 1983-1/2 VW Vanagon
Volkswagen Vanagon Wasserboxer - Water cooling means improved
performance for this already delightful design
Road & Track, June 1985
What does the 1983-1/2 Volkswagen Vanagon have in common with Porsche's
legendary 935 Turbo racing car? If you guessed that both have rear
engines, you're right. And if you guessed that both engines are boxers
-- a flat-4 in the VW and a flat-6 in the Porsche -- you're right again.
But did you know that like its racing cousin, the Vanagon's latest
4-banger has water cooling? Volkswagen's reasons for turning on the
waterworks are not unlike Porsche's, at least on one count --
thermodynamic efficiency. When Porsche began turning up the boost on
its turbocharged racing 6-cylinders, it found itself reaching the limits
of the air-cooled engine's performance. Simply put, the factory
discovered that even the most effective fan could move only so much air
past hot cylinder barrels. So the wizards of Weissach devised water-
cooled cylinder heads used with air-cooled cylinders to bring operating
temperatures within optimum levels and make the turbocharged Porsche
Porsche racing engine one of the most powerful in the world.
Meanwhile, back in Wolfsburg, VW had been having similar problems with
its air-cooled Vanagon powerplant. Displacing almost 2.0 liters, the
4-cylinder was at the ragged edge of efficiency. At 67 bhp, the Type 4
(located at the rear of a large box and subject to less than ideal
airflow) was doing all an air-cooled engine could to propel a 3300-lb
vehicle and stay alive. Something had to be done and that something
was water cooling, not just the cylinder heads, but the cylinders as
well. There were other reasons for this change, namely, better fuel
economy and less noise. This last point is very important especially
in a country such as Switzerland, which has very strict noise
regulations.
After nearly three years of development the Wasserboxer has been
unveiled. Similar in outward appearance to the air-cooled version, it
is internally almost totally new. For example, the engine is shorter
because the water-cooled cylinders are closer together than their air-
cooled predecessors. Thus, the crankshaft is new and it has a shorter
stroke than the old crank (69.0 versus 71.0 mm). The crankcase is also
new and now has an integral water jacket that occupies the space once
filled by the finned cylinder barrels used in the air-cooled engine.
The new barrels are now cylinder liners and repose inside the hollow
water jackets. Metal O-rings, top and bottom, form a seal to keep
coolant from seeping into the crankcase or the combustion chamber.
The cylinder heads, while bearing a visual resemblance to their air-
cooled counterparts, are redesigned and have their own water jackets
with coolant openings at each end. Larger intake and exhaust valves
are actuated by the usual rocker arms and pushrods and the intake and
exhaust passages have been reshaped for better flow. Unlike other VW
powerplants, the Wasserboxer has Heron-type combustion chambers. That
is, the pistons are deeply dished and most of the combustion chamber is
in the piston and not in the cylinder head. Furthermore, the shape of
the combustion chamber and the location of the sparkplug (it's angled
toward the intake valve) provide for smooth and efficient burning of the
fuel/air mixture and produce a uniform burning rate by controlling
combustion. According to Volkswagen, this results in smooth power
production and permits the use of an 8.6 versus the 7.3:1 compression
ratio of the air-cooled version.
Although the Wasserboxer's camshaft is conventionally located in the
middle of the case, just below the crank, the cam's lift and profile
has been altered to develop more power at low- and mid-rpm ranges.
Elsewhere inside the engine, diameters of the piston pins, the main
bearing journals and the rod journals have been increased.
Topside, there's a redesigned fuel injection system, which VW calls
Digi-jet. An offshoot of the previous Bosch L-Jetronic, the new
system's control unit uses digital rather than analog technology and,
generally speaking, it is simplified. Based on experience with our own
long-term Vanagon (see R&T, April 1983) and reader feedback as well,
we'd conjecture that the Digi-jet system is a response to electronic
gremlins bedeviling the first-generation Vanagon's fuel injection.
In any case, one of its functions is limiting engine speed to 5400 rpm
by shutting off the fuel pump. Sensing of engine rpm is performed by
the ignition control unit, part of the Wasserboxer's Hall-type
transistorized ignition.
Water 'bout the Vanagon's unusual cooling system? Puns aside, it's
quite cleverly done with the radiator mounted at the front of the bus
behind an additional grille (as in previous water-cooled Vanagon
diesels; the original opening on the air-cooled model was used only
for cockpit ventilation). A thermostatically controlled 2-speed fan
comes on when needed to reduce the temperature of the coolant, which
flows back to the engine through two steel tubes located beneath the
body. When the engine is cold, the coolant remains in a closed loop
and flows only through the cylinder jackets and heads. But as the
temperature increases, the thermostat opens, allowing coolant to travel
through the radiator and (if desired) through the heater cores,
including the usual under-dash unit and an auxiliary heat exchanger
under the rear seat. This rear heater provides additional warm air
for back-seat passengers.
By converting to water cooling, VW got itself a bonus of sorts: extra
horsepower. It seems that the old crank-driven fan required about 3.4
horsepower, where the water pump now used needs only 0.7 bhp.
What does it all mean? A 22-percent improvement in horsepower, a
19-percent improvement in fuel economy (as measured by the EPA) and a
50-percent reduction in noise levels. To be specific, the Wasserboxer
develops 82 bhp compared to the air-cooled engine's 67, gets 19 vs 16
mpg in EPA city testing, and registers 77 instead of 80 dBA in European
drive-by tests. What do you get? A better Vanagon and perhaps the best
all-around family van yet from Volkswagen.
In redesigning the Vanagon's boxer engine, VW also reengineered the
gearbox, reinforcing the housings and the pinion and main shafts. The
shift forks, shift rods and selector interlock assembly were simplified
as was the reverse gear assembly, which now uses helical gears. The
number of mounting points was reduced from five to three, two at the
gearbox and one at the engine. Because the engine is shorter and sits
farther back in the chassis, the transaxle has been moved forward
proportionately, reducing the driveshaft angle to zero. This places
less strain on the inboard CV joints and increases their lifespan.
Although Europeans have a choice of either a 4- or 5-speed manual
gearbox as well as a 3-speed automatic, U.S. buyers get only the 4-speed
and the automatic. Volkswagen of America says that these transmissions
are adequate, given the power, torque and flexibility of the new engine.
Finally, if you're wondering why VW chose to stick with the flat-4
rather than switch to the Rabbit's sohc inline-4, it's because
1. the boxer is compact, has a low center of gravity and because of
water cooling, has closer cylinder spacing and is shorter than the
air-cooled version; 2. its opposed-cylinder design provides good
balancing of inertial forces and results in smoothness commensurate with
an inline 6-cylinder; and 3. the water-cooled engine can be built on
practically the same assembly line as the air-cooled powerplant. And the
possibilities of other water-cooled versions are fascinating: a
6-cylinder water-cooled 3.0 liter, perhaps?
At this point, some of you VW van and Beetle owners are undoubtedly
wondering if the new Wasserboxer can be retrofitted into these bodies.
"Anything is possible," says a Volkswagen of America spokesman. But he
cautions that such a project is far from simple (recall the different
drivetrain mounting) and that cost of conversion would far outweigh
whatever benefits might be derived from using the water-cooled
powerplant.
Since we mentioned the Rabbit engine, you may recall that it made a
brief appearance as the Vanagon diesel powerplant. But that engine has
been discontinued in the U.S. because of a changing market that has lost
its infatuation with the diesel.
Performance is something you won't find lacking inthe water-cooled
Vanagon (at least relatively speaking), because it's practically 3
seconds quicker than the air-cooled VW from 0 to 60 mph, at 18.3 sec vs
21.2. But the numbers don't tell the whole story and this is that the
new Vanagon is decidely more responsive in traffic. Also, out on the
highway, you're less likely to find yourself plugging up that long if
gentle grade in 3rd. It's smoother too and most definitely quieter,
a significant 3-4 dBA quieter across the board compared to the air-
cooled version. In fact, we heard more wind noise than we did
mechanical clatter. Perhaps this overall quietness induced us to
drive harder than we did in the air-cooled version.
Though we tested the 4-speed, we also sampled an automatic Vanagon. Most
of the staff strongly preferred the manual-shift model because it allows
one to use the engine's power optimally. The automatic, while certainly
adequate for casual cruising, and very handy indeed in stop-and-go
tedium, suffers from having only three gears and, what's more, their
shift points are set too low. To extract decent performance from the
engine, it's necessary to operate the shifter manually, holding it in
gear. This is not an easy task because the shift lever is a bit hard
to reach and its movement a bit stiff.
Actually, it's easy to overlook the Vanagon's few shortcomings because
the VW has so many positive attributes. It handles well and rides
smoothly, thanks to its independent suspension and low engine mass.
In fact, the overall feel is that of a European family sedan, an Audi
perhaps, or one of VW's own models. This is especially true inside
where one finds similar materials used in a passenger car manner. And
let's not forget fit and finish, which are as good as you'd find in any
car. One more thing: The Vanagon is roomy. Want to see the ultimate in
the use of space? Then check out the Vanagon camper, which has
everything including the kitchen sink.
In our initial Vanagon road test (R&T, July 1980), we said that the VW
van "is clearly the leader in technological development in its class."
That's still true, as we discovered driving the standard shift and
automatic Wasserboxers. The new engine's power, flexibility, economy
and quietness are delightful and give the VW van a level of performance
that is commensurate with its design.
PRICE ENGINE
List Price, all POE ....... $11,700 Type ...... water-cooled ohv flat 4
Price, as tested .......... $12,265 Bore x stroke, in ..... 3.70 x 2.72
Price as tested includes mm ..... 94.0 x 69.0
AM/FM/stereo cassette ($565) Displacement, cu.in ........... 117
cc ............. 1915
GENERAL Compression ratio ........... 8.6:1
Curb weight, lb/kg .. 3400 ... 1544 Bhp @ rpm, SAE net ...... 82 @ 4800
Test weight ......... 3635 ... 1650 KW ........... 61 @ 4800
Weight dist (with driver), Torque @ rpm, lb-ft .... 106 @ 2600
f/r % ..................... 56/44 nm ....... 144 @ 2600
Wheelbase, in./mm ... 96.9 ... 2461 Fuel injection ......... VW Digijet
Track, front ........ 62.3 ... 1583 Fuel requirement .. unleaded 91-oct
rear ......... 61.8 ... 1570
Length ............. 179.9 ... 4569 DRIVETRAIN
Width .............. 72.6 ... 1844 Transmission .......... 4-sp manual
Height ............. 77.2 ... 1961 Gear ratios:
Trunk space, 4th (0.85) .............. 4.13:1
cu. ft ... 36.6+49.4+22.9 3rd (1.26) .............. 6.12:1
liters ... 1037+1399+649 2nd (2.06) .............. 10.01:1
Fuel capacity, 1st (3.78) .............. 18.37:1
U.S.gal/liters ... 15.9 .... 60 Final drive ratio ......... 4.86:1
CALCULATED DATA CHASSIS & BODY
Lp/bhp (test weight) ......... 44.3 Layout ..... rear engine/rear drive
Mph/1000 rpm (4th gear) ...... 18.2 Body/frame ............. unit steel
Engine revs/mi (60 mph) ...... 3300 Brake system,
10.9-in. (278-mm) discs front,
R&T steering index ........... 1.29 9.9x2.2-in. (252x55-mm) drums
Brake swept area, sq in./ton.. 219 rear; vacuum assisted
Wheels ......... steel 14 x 5-1/2J
Tires ........ Michelin X, 185SR-14
Steering type ....... rack & pinion
Turns lock-to-lock ......... 3.8
Front suspension:
unequal-length A-arms, coil
springs, tube shocks, anti-roll
bar
Rear suspension:
semi-trailing arms, coil springs,
tube shocks
ROAD TEST RESULTS
ACCELERATION FUEL ECONOMY
Time to distance, sec: Normal driving, mpg ...... est 19.5
0 - 100 ft ................. 3.7 Cruising range, mi (1-gal res) 293
0 - 500 ft ................. 10.9
0 - 1320 ft (1/4 mi) ....... 20.9 HANDLING
Speed at end of 1/4 mi, mph .. 63.5 Lateral accel., 100-ft radius,
Time to speed, sec: in g. ....................... na
0 - 30 mph ................. 4.8 Speed thru 700-ft slalom, mph .. na
0 - 50 mph ................. 12.5
0 - 60 mph ................. 18.3
0 - 70 mph ................. 31.5
SPEEDS IN GEARS INTERIOR NOISE
4th gear (4900 rpm) .......... 88 Constant 30 mph ................ 65
3rd (5300) ................... 64 50 mph ....................... 72
2nd (5300) ................... 39 70 mph ....................... 78
1st (5300) ................... 22
SPEEDOMETER
30 mph indicated is actually.. 29.0
60 mph ....................... 59.0
BRAKES
Minimum stopping distances, ft: Control in panic stop ... very good
From 60 mph ............... 178 Pedal effort for 0.5g stop, lb.. 25
From 80 mph ............... 297 Fade: percent increase in pedal
Overall brake rating .... very good effort to maintain 0.5g
deceleration in 6 stops .. 36
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