Talk:Twincharger
Interwiki de:wp
the article in de:wp is only an disambiguation.--Ottomanisch (talk) 07:58, 28 August 2010 (UTC)
Title
It's a good article, but I'm not convinced that 'twincharging' is actually a generic name - rather it's what VAG call their version of it. There only seem to be three manufacturers who use it - and neither of the other two use twincharging as a name. However, I can't think of a better page title to use instead!Jellyfish dave (talk) 12:46, 18 April 2013 (UTC)
Notabillity
It is a good artical, but are these systems not the same as used on GM diesel (compression ignition) engines? They a variety of turbocharged and supercharger (rootes blower type) setups. Andrew Robbins (talk) 03:12, 31 October 2014 (UTC)
Toyota 4A-GZE
It mentions the 4A-GZE in the article in connection with an electromagnetic clutch that can disengage the supercharger to reduce parasitic losses...however, I think it is important to note that this is nothing to do with twincharging, rather it is intended to bypass the supercharger and allow the engine to operate as a normally aspirated unit when under low-load conditions, as described here: http://mr2.com/TEXT/SuperChargerInfo.html )..45Colt 10:48, 11 February 2015 (UTC)
Efficiency
Suggest replacing the following text: "However, the efficiencies of the turbo and supercharger are also multiplied, and since the efficiency of the supercharger is often much lower than that of large turbochargers, this can lead to extremely high manifold temperatures unless very powerful charge cooling is employed. For example, if a turbocharger with an efficiency of 70% blew into a Roots blower with an efficiency of 60%, the overall compression efficiency would be only 42% -- at 2.8 pressure ratio as shown above and 20 °C (68 °F) ambient temperature, which means that air exiting the turbocharger would be 263 °C (505 °F), which is enough to melt most rubber couplers and nearly enough to melt expensive silicone couplers. A large turbocharger producing 27 psi (1.9 bar) by itself, with an adiabatic efficiency of around 70%, would produce air at just 166 °C (331 °F). Additionally, the energy cost to drive a supercharger is higher than that of a turbocharger; if it is bypassed, the load of performing compression is removed, leaving only slight parasitic losses from spinning the working parts of the supercharger. The supercharger can further be disconnected electrically (using an electromagnetic clutch such as those used on the VW 1.4TSI or Toyota's 4A-GZE, although this is not because it is a twincharged engine; it is intended only to bypass the supercharger under low-load conditions) which eliminates this small parasitic loss."
with this: "The work of the combined turbo and supercharger are however divided (or shared), and since the efficiency of the supercharger is often much lower than that the turbocharger, the more efficient compressor (i.e. turbocharger) should perform most of the work otherwise this can lead to extremely high manifold temperatures unless very powerful charge cooling is employed. Additionally, the energy cost to drive a supercharger is higher than that of a turbocharger; if it is bypassed, the load of performing compression is removed, leaving only slight parasitic losses from spinning the working parts of the supercharger. The supercharger can further be disconnected electrically (using an electromagnetic clutch such as those used on the VW 1.4TSI or Toyota's 4A-GZE, although this is not because it is a twincharged engine; it is intended only to bypass the supercharger under low-load conditions) which eliminates this small parasitic loss."