Ever wondered how WRC cars manage to deliver 300 bhp and above from an engine that, by rule, cannot exceed 2.0 liters of displacement? How on earth do the heavy, low-revving diesel engines in cars today stay competitive? Or what is it that makes it possible for the Bugatti Veyron to break the 1000 bhp threshold? Well, it certainly isn’t witchcraft. By means of “forced induction”, turbochargers today boost the automotive industry to a new direction of smaller, more-efficient and bloody good fun engines.
Volkswagen like to brand their most successful turbo diesel range as TDI while Porsche, being more plain about it, call their turbocharged cars, Porsche (insert model here) Turbo. BMW, on the other hand, would never hesitate to utter their own terms like “bitrubo” or “TwinPower” whenever describing the latest M5 engine. The variety of depicting turbocharged cars is bountiful, but essentially the principles of work remain the same in every case.
Beware reader, as I am now going to get technical:
In order to understand how a centrifugal turbocharger works, one must also have some basic knowledge on how four-stroke, piston engines work. We have an engine block that contains the cylinders, right? Inside each cylinder, a piston moves up and down. Every movement made is a phase, a stroke. First we have intake – a mixture of fuel and air is sucked into the cylinder. Compression is the second stroke where the cylinder moves up and…well…compresses the molecules in the mixture. The next ignition stroke is downwards as the piston experiences pressure coming from the combustion of the mixture. The exhaust stroke has the job to expel the remaining gases through the exhaust valve. Then the intake valve lets in a new batch of fuel mixture and thus the process is repeated.
However, as far as turbochargers are concerned, exhaust gases are not exactly throw-away material. Put simply, the turbocharger utilizes the energy of exhaust to compress the the newly arrived batch of air which is to be shoved in the cylinder. More air molecules means that more fuel can be injected into the mixture and more fuel means more power.
Before those exhaust gasses reach the exhaust system they go trough a turbine connected to a shaft. The more exhaust that goes through the turbine blades, the faster they spin. On the other end of the shaft we find a compressor which welcomes fresh air from the atmosphere, compresses it using the force of the turbine and then feeds it into the engine. To further increase the efficiency of the turbocharging system, an intercooler is added – it looks much like a car radiator but instead of containing cooling fluid, it holds the compressed air from the compressor. Air is denser when cooler and that’s exactly what the intercooler does – it cools the incoming air.
There are issues however. First of all, a turbine amidst the flow of exhaust is essentially an obstacle. The exhaust stroke has to deal with more back-pressure thus being slightly less efficient. A functional turboshaft has to handle extreme forces (speeds go up to 150 000 rpm within the turbocharger) so a special kind of baring is needed – liquid ones or state-of-the-art ball bearings. The latter is more efficient but more expensive. Then there’s the dreaded turbo lag. The problem here is that when you put your foot down, the response is far from electric. The turbine needs some time to kick off and start spinning the compressor blades. That’s why at low engine rpm one can’t really tell if the car has a turbo or not.
There are various ways to tackle this nuisance. Make things smaller and lighter. Tiny turbochargers will grant you that off-the-line jolt but won’t be too good on the upper rpm range. Besides, if too much exhaust starts going through a relatively small turbine things may get hot and disbalanced. Usually however, there’s the wastegate in most turbines – a valve that knows how much exhaust passes through and regulates the flow by simply diverting some of the gases away from the turbine. Some companies have started putting more than one turbochargers in their cars. One small and the other, big. The small one guarantees a more immediate response while the big one takes over at higher speeds.
Essentially, that’s the story with turbochargers. We can further dive into numbers and calculations about pressure and efficiency but this, I think, is already nerdy enough. Hopefully some of you learned something new while others refreshed their memory on how the turbocharger brings easy power to our everyday lives.
Do you know that funny little wingless cartoon birds. Well if you do, you are probably fan of the popular game “Angry Birds”. And more importantly we have some really good news for you. If you are looking forward to this year’s Formula 1 and are addicted to this particular game, then you will see some characters from the game onto the racing track. Till the present, maybe Formula 1 was one of those few areas where we couldn’t see our favourite characters. Nevertheless, recently the Finish company Rovio announced their newly signed contract with the Formula 1 racer Heikki Kovalainen. The Finnish god of the racing-track will wear a helmet, which was especially ornated with the logo of “Angry Birds” and in addition is designed to look just as the red wingless bird from the game. Actually, the Finnish F1 star has already debuted wearing this helmet on this weekend’s inaugural Formula 1 race in Melbourne, Australia. Furthermore Kovalainen seems to be a big fan of the game, and shares that given this fact and since he is Finn (as the funny characters are) he would be proud to wear the helmet.
To have Peugeot‘s latest hybrid modular technology it takes a 2.0-litre HDi engine and a 37 bhp electric motor put on a single frame. The diesel engine deals with the front axle while the electric motor operates the rear. Such a setup was fist used in the 3008 HYbrid4. Now the Peugeot 508 RXH and 508 Saloon also join the company’s hybrid fleet by succumbing to the HYbrid4 badge.
In search for an executive saloon but tired of BMWs or Audis and Mercedeses? They are the usual choice but one can never get hurt from trying something different. Oh Look! Here’s an Opel Insignia… and it’s been tweaked by German motoring specialists JMS. It’s a starter project with more options due to come. I basically depends on the customer.
Here is a nice video of Mercedes-Benz SLS AMG Roadster tested by Sport Auto.
Abt Sportsline has announced their tuning program of the new 2012 Audi A3. The name of the project is ABT AS3, which stands for “happiness in driving, always and everywhere” as Mr. Hans-Jürgen Abt stated.
Volkswagen has announced the UK price list of the new 2012 Passat Alltrack. Esentially, the vehicle features raised ride height, 4MOTION four-wheel drive and rugged body enhancements.
New stuff from SR Auto. Well, actually it’s the BMW M5, the E60 one. A project called the “Excalaber” – the strange 
Vorsteiner‘s GTRS3 program for the BMW M3 Coupe is not really something that came out yesterday – it’s been around for almost two years now. However, it sill is hot by today’s standards and the latest proof of that is what we see here – a matte blue GTRS3 M3 having a photo shoot in Taiwan and generally gaining popularity.
