In conjunction with it’s 70th anniversary making oil burners, Mercedes Benz had something very interesting to show us at the 2005 Geneva Motor Show.
The Mercedes Benz SLK320 CDI Tri-Turbo Vision
Mercedes Benz’s history making diesel engines goes all the way back to 1935 when they rolled out the 260D, a diesel powered mid sized sedan making 45 horsepower with it’s 2.5 litre inline-four diesel engine. Diesels were only invented 38 years before that, by Rudolph Diesel.
Fast-forward 70 years later, Mercedes Benz showcased their concept SLK320 CDI Tri-Turbo Vision powered by a new 3.0 litre common-rail direct injection tri-turbo diesel V6 engine. The oil burner comes with 4 valves per cylinder. What’s special about this concept engine is the usage of 3 turbochargers to minimize turbo lag and maximize performance.
How does it work?
The engine is driven by 2 small turbochargers and 1 large turbocharger. Each small turbocharger drives 1 bank of cylinders at both sides of the engine, and these are in turn are connected to 1 single large turbocharger positioned in the middle of the 2 banks of cylinders in the V6 engine. At low RPMs, all three turbochargers are at work, with most of the boost provided by the small turbochargers while the big turbocharger spins up. Later, a bypass is activated and air flows through the big turbocharger alone supplying a huge boost and massive amounts of torque.
What does this give us? 286 horsepower and 628Nm of torque. The car goes from 0-100km/h in 5.3 seconds. How does this figure stand up to the SLK350 powered by a petrol engine? The SLK350 does it in 5.1 seconds. Only 0.2 seconds difference. Very impressive.
The engine also makes 14 extra horsepower and 69Nm more torque than the BMW 3-litre inline-6 turbodiesel which won the diesel engine of the year award for 2005. However the BMW oil burner is a production engine but this Mercedes Benz is still a concept. Mercedes officials say it is still too expensive to mass-produce.
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unimpeachable….
As you mentioned, the tri-turbo concept is used to reduce turbo lag. Using a turbocharger, exhaust gasses are extracted to 'power up' the turbo pump. That is why the turbo lag exists, because it takes time for enough exhaust gasses to be collected and run the turbocharger. Usually what happens is if you look at the power curve, it gives relatively low hp at low rpms. As the rpm goes higher, the hp steadily increases, until a sudden surge of power at the moment the turbocharger kicks in. But you just gave the max hp output. Any details on how much the turbo lag is reduced?
I can imagine that having a concept of tri-turbos is a brilliant way to reduce turbo lag, especially since turbocharging is the only viable way to make diesel engines produce more respectable power outputs. But having more components means a lower overall engine efficiency, and don't mention the cost increase. it would be interesting to see how Merc tackles this problem.
I think this is just another form of sequential turbo charging which we've seen in the Mazda RX7 since years ago. Just that this one has 3 turbos because there are 2 sets of exhaust headers in the V-formation engine so they have 2 of the smaller turbines insead of one. One small turbine for each exhaust header.
Mercedes did not release any torque and horsepower curve charts.
should be 0.2 seconds difference
paul,you too should learn simple math :)
hehehe. corrected. more likely to be a typo. look at the time i blogged it.
"I think this is just another form of sequential turbo charging which we’ve seen in the Mazda RX7 since years ago. Just that this one has 3 turbos because there are 2 sets of exhaust headers in the V-formation engine so they have 2 of the smaller turbines insead of one.'
Correct me if I'm wrong – So basically, Mercedes can simplify things by using an inline-six instead of a V6.
I'd like to mention, also the Supra TT and the Mitsubishi 3000GT TT (aka GTO! Fun cars, but 3000GT on the heavy side.
Also how not forgetting the Nissans: the Nissan 300ZX Fairlady, Silvia and Skyline GTR. All available with twin blowers, and all started in the 80's too.
too quick on the draw, scratch the Silvia, since it's one of your favorites and it's only a 4 cylinder so twin blower setup is technically complicated.
when will we ever get cheap diesel passenger cars with roadtax comparable to petrol ones??
still remember this chick of mine who drove a wira 2.0 diesel… hahahaha…
Too many mechanicals, Mercs always comes out with unconventional way of doing things. Like the sensotronic brakes, 1.8L engine kompressor etc. They do not contribute to durability like they use to and with too many electronics, the maintenance cost is going to be high. Three turbo charges will be expensive to maintain and trouble shoot if there is a problem, why not just try VGT or improve on it, instead. Borg-Warner VGT can increase hp by at least 30% and improve fuel consumption too. The way to go forward now is to increase power and decrease fuel consumption but without jeopardising comfort and durability.
Jason, MB already knows that it is too expensive. So it was more of a PR exercise to impress the normal motoring public – "Look, 3 turbos!".
(Although I think the Bugatti Veyron has 4 turbos)
Where is a good place to find out more about VGT?
I think electric seems promising too. Toyota is working on an electric supercar. Imagine, each wheel driven by its own motor, with minimal energy loss through heat, or the drivetrain.
walao eh….. dooling……
Hi CH,
Yes I know they said too expensive to produce. But for a big company like Mercs to come out with such an idea and waste money on this kind of test, it is silly isn't it? Just like previously there were some Malaysian investing in an Australian Company called CMC Systems producing small engine generators to be installed in the boot so as to produce extra electricity for the car of the future. Their argument was future cars with electric seats, sunroof, etc would need more electricity so they came out with this system. Maintaining the engine in front is already a cost and to maintain a small generator in the boot? Silly idea isn't it. Like the latest Mercs, just install 2 batteries for the car solves the whole problem. Batteries are cheap and can be changed anytime, anywhere. But a generator has many parts, Just to troubleshoot will kill. We are slowly moving towards less labour intensive scenario in Malaysia. Time is money. We can't afford to visit the workshop every other month just to replace parts or troubleshoot problems. When C&C or rather Daimler Chrysler gives 3 year unlimited mileage warranty on its cars, it was pointless for me. My car's aircond compressor were replaced twice, once for water pump, once for alternator, twice for recall on the Sensotronic Brakes, and I can't remember is it twice or thrice for the jerkings in the transmission. What we need is durability, eventhough the warranty period can be 1 year but the parts can withstand wear and tear at a longer time frame.
Anyway to your question, please check website www.3k-warner.de OR at worldwide.hyundai-motor.com/common/html/innovation/powertrain_common.html
Hope you r not offended. Just trying to make my point. It seems DC maybe going the wrong direction.
CH,
the second website at hyundai has four alphabets missing. There should be "html" after the word common, ie. "………/powertrain_common.html". Anyway this VGT is different from Paul's VGT engine. This VGT means Variable Geometry TurboCharger.
ah, great. thanks, mate. Impressive. I wonder when if either will make it into affordable consumption.
it's not really a new thing.. but a new concept.. some cars nowadays even incorporate a quad turbo system solely to output monstrous power.. haha.. i wonder how long can the car be revved
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neurra: the only commercially available quad turbo I know is the Bugatti Veyron. Are there others?