Table of contents
motorcycles
Technology: exhaust gas cleaning
Technology: exhaust gas cleaning
Scourer
How clean is the F 650 GS really, asked MOTORRAD in issue 10. Now the BMW and its competitors had to go to the exhaust test bench again.
Waldemar Schwarz
07/03/2000
When comparing the 650 enduros, MOTORRAD examined the efficiency of the various exhaust systems in issue 10/2000. On the test bench, astonishing things came to light. The representative with at least the theoretically best technology for reducing pollutants, the BMW F 650 GS with injection and regulated catalytic converter, emitted the lowest amount of pollutants in the ECE 40 exhaust cycle among competitors Aprilia Pegaso, Honda Transalp and Suzuki Freewind.
Buy complete article
Technology: exhaust gas cleaning
Scourer
6 pages) as PDF
1.00 €
Buy now
But while the competitors delivered similar values after a warm start, the BMW suddenly produced 30.4 g / km carbon monoxide, 34 times the original amount. After several attempts, the first surprise quickly turned into certainty: the BMW recognizes the test cycle based on a number of parameters. The lambda control then ensures low levels of pollutants. In comparable operation on the road, a different regulation of the mixture preparation comes into effect.
When asked about this discrepancy, the engineers from Munich argued: “Together with the TU Darmstadt, BMW has created the typical driving profiles of a motorcyclist in everyday use. Today’s test cycle for motorcycles hardly affects this area. Real driving operations are not or only insufficiently covered, which is why the existing exhaust gas test cycle is no longer up-to-date.”
A logic that MOTORRAD can understand, but not the conclusion that BMW draws from it: using tricks to meet the limit values of the emissions test.
The BMW men bring up technical problems: “Due to the high efficiency and the low friction of the engine, the engine control calculates correspondingly short injection times at low loads. These in turn cause problems in the formation of the mixture, the consequence of which would be a more or less pronounced engine jolt. For this reason, for reasons of driving comfort, the single-cylinder must deviate from the optimal lambda value at the lowest loads and the fuel / air mixture must be enriched.”
But overall, the BMW technicians are certain, the F 650 GS not only sets new standards in terms of torque and power, but also in terms of consumption and emissions in this class. The Bavarians wanted to provide proof in the presence of MOTORRAD.
In order to investigate the pollutant behavior, especially that of carbon monoxide, which is obviously difficult to control, in speed ranges outside the legal cycle, MOTORRAD selected two further cycles, which simulate cross-country traffic with a maximum speed of 120 km / h and on the other hand motorway use with a maximum of 140 km / h . All measurements were made with a warm start, i.e. with the engine at operating temperature.
For comparison, the Honda Transalp with an uncontrolled catalytic converter and secondary air system and the Suzuki Freewind without any exhaust gas purification competed – initially on the exhaust test bench of the neutral TuV Suddeutschland.
The first measurements for inner-city operation already confirm the high level of pollutant emissions from BMW, which was already noted in issue 10. With 29.2 g / km of carbon monoxide CO, it emitted many times the Transalp, which this time with 8.2 g / km CO after the warm start was slightly higher than during the cold start. The Suzuki also surpassed the cold start values with 24.7 g / km. When it comes to HC hydrocarbons, BMW also emitted 82 percent more than its competitors. There was almost a tie when it came to nitrogen oxides (NOx) alone.
In the next discipline, the extra-urban cycle that cars have to complete for homologation, the BMW was just ahead of the curve when it came to carbon monoxide. At 15.5 g / km, their balance was more favorable than the 18.5 and 18.7 grams from Honda and Suzuki, but not in terms of HC and NOx emissions.
In the motorway cycle, the three test persons moved at a constant 140 km / h, interrupted by braking to 110 and 80 km / h with subsequent full-load acceleration, that is, the motorway speed typical for a journey with braking maneuvers. In this discipline, the Transalp went beyond the scope. With 39 g / km CO, it emitted more than twice as much as the BMW and almost 40 percent more than the Suzuki without any exhaust gas purification. The picture was similar for HC emissions: at 1.31 g / km, it was significantly higher than that of the BMW with 0.53 and the Suzuki with 0.46 g / km. In the NOx alone, it was able to clearly undercut its rivals.
Additional tests on the exhaust test bench of BMW development with similar cycles showed the same tendencies. In the case of the BMW, the CO values leveled off at around eleven g / km at even higher loads, while the Suzuki showed concentrations of 23 to 39 grams, depending on the load. The Honda emitted over 42 grams – more than the test bench can measure.
The water-cooled engines of the BMW and Honda with complex systems for reducing pollutants can by no means show an overwhelming superiority over the air-cooled carburettor engine of the Suzuki without any measures to reduce the harmful substances. The BMW technicians are also aware of this, and although they see the undeniable advantages of injection, such as good mixture adaptation to various operating conditions such as a cold start, they also know the problems.
In fact, there still seem to be development deficits in injection technology for large single cylinders: The current injection valves are difficult to manage the balancing act between the smallest quantities in the partial load and large quantities in the full load range.
This thesis is proven by an F 650 GS prepared by BMW for demonstration purposes, which MOTORRAD editors were able to move around Munich. A control unit that maintains the mixture over almost the entire load range around lambda 1 and thus nips the emergence of high concentrations of pollutants, the so-called raw emissions, in the bud, had to prove its drivability in everyday operation on the road. In contrast to the series or the old F 650 version with carburettor, the modified model annoys you with unacceptable jerking when driving at constant speed in urban areas at 50 km / h in fourth gear or out of town in fifth gear up to 90 km / h.
The balance of the three different concepts is food for thought. The BMW is anything but environmentally friendly not only in city traffic, but also when strolling along country roads, but with increasing load it becomes a clean man. In stark contrast to the Honda, which shows a decent pollutant behavior in the lower to medium partial load range, but then produces carbon monoxide en masse at higher load and speed ranges. The age-old concept of the Suzuki Freewind doesn’t leave a bad impression. She is not really an honest man in any area, but nowhere is she a real arsonist either.
Both BMW and Honda show that there is still a lot to be done when it comes to optimizing emissions from two-wheeled engines: The development activities in Munich show that the BMW engineers also see great potential here.
Technology: Comparison of pollutants (archive version)
Role play
read more
Related articles
-
www.jkuenstle.de 7th pictures Unger 1/7 After the tourist faction is well represented in the long-term test fleet with the Triumph Trophy and BMW GS, the…
-
PS reader question about motorcycle technology – cleaning the radiator
www.factstudio.de, Joachim Schahl 7th pictures archive 1/7 Picture gallery, technical question: cleaning coolers. Werner Koch 2/7 When the delicate…
-
Annual review test and technology
fact motorcycles Annual review test and technology Annual review test and technology Focal points What a year: We are celebrating 100 years of MOTORRAD,…
-
Technology: comparison of pollutants
motorcycles Technology: comparison of pollutants Technology: Comparison of pollutants (archive version) Role play Exhaust gas cleaning is not only…
-
Technology of the 2002 model year
motorcycles Technology of the 2002 model year Technology of the 2002 model year Undercover In the 2002 season it is the inner values that count, and…
-
Technology of the new 600 super sports car
counselor technology & future Technology of the new 600 super sports car Technology of the new 600 super sports car New base The new 600 super athletes…
-
MotoGP technology: valve trains
counselor workshop MotoGP technology: valve trains MotoGP technology: valve trains Sex offender Stoner? Traction control? Tire technology? Happiness? It…
-
Technology Superbike developments
Suzuki 16 pictures archive 1/16 Variable valve control Suzuki GSX-R 1000/2016. archive 2/16 Suzuki engine technology in detail: low speed. archive 3/16…
-
Exhaust test Yamaha FZS 1000 Fazer
Jahn accesories Exhaust & silencer Exhaust test Yamaha FZS 1000 Fazer Exhaust test Yamaha FZS 1000 Fazer Sound appeal 17 Accessory silencers for the…
-
Technology: engine technology super sports car
fact 23 pictures fact 1/23 The Honda Fireblade has been a great performer for twenty years. PS takes a close look at the development of engine…