Monthly Archives March 2014

BMW group front-wheel-drive models will use Aisin transmissions

With more collaborations between BMW and Toyota, we will find more of the Japanese company’s product in the German brand (Aisin is owned by its parent company Toyota).

According to BMW, their future FWD platform sedans’ transmission will be supplied by Aisin (the current BMW RWD cars’ transmission are majorly sourced from ZF).

The new Aisin transmission is improved for the damping capability of the torque converter, which is suitable for turbo engine. The turbo engine’s low end torque results the engine run at low RPM range more time. While this helps to optimize fuel consumption, it also significantly increases the level of torque fluctuations...

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Why the Lexus LFA is a special supercar – part 2

In part 1, we reviewed the body construction of the LFA. Now let us take a look at its heart – the 1LR-GUE 4.8L V10 engine.

Some may criticize it does not has fuel direct injection. However let’s see what is the benefit of using direct injection.

By using direct injection, the internally sprayed liquid fuel can lower the cylinder’s temperature, therefore lower the possibility that the fuel to be ignited by the high engine temperature. Therefore, a higher cylinder compression ratio can be utilized, and the higher compression ratio can thus raises the output and lower fuel consumption...

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Why the Lexus LFA is a special supercar – part 1

Index

Why the Lexus LFA is a special supercar – part 1 (carbon fiber technology)
Why the Lexus LFA is a special supercar – part 2 (engine)

When the Lexus LFA went on sale in late 2010 and early 2011, some of its specifications seem to be outdated: for example its V10 engine still uses traditional port injection for the fuels, while the 10-times-cheaper IS250 has already incorporated fuel direct injection for 4 years; and also the LFA is using a single clutch 6 speed automated sequential transmission, while there are plenty of sports cars using a more advanced double clutch transmission.

These indeed are shortcomings of the LFA, caused by the lengthy development cycle ...

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Media road test: BMW M235i vs. Mercedes CLA45 AMG vs. Subaru WRX STI

This road test comes from MotorTrend’s 2014 June Issue.

Note: If you cannot see the whole table when you are browsing using iPhone, you can turn your phone by 90 degree and view the full width version of the table.

2014 BMW M235i 2014 Mercedes Benz CLA45 AMG 2015 Subaru WRX STI (Launch Edition)
POWERTRAIN/CHASSIS
DRIVETRAIN LAYOUT Front-engine, RWD Front-engine, AWD Front-engine, AWD
ENGINE TYPE Turbocharged I-6, alum block/head Turbocharged I-4, alum block/head Turbocharged flat-4, alum block/heads
VALVETRAIN DOHC, 4 valves/cyl DOHC, 4 valves/cyl DOHC, 4 valves/cyl
DISPLACEMENT 181.8 cu in/2979 cc 121.5 cu in/1991 cc 149.9 cu in/2457 cc
COM...
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Why the Audi A6 is hard to maintain

Replacing the oxygen sensor – this task sounds easy.

For some cars this is actually an easy job. But for some it isn’t. Take this Audi A6 for example, the two red arrows point to the two oxygen sensors on its left exhasut manifold (the right manifold has another 2, too).

AudiA6O2Senser

Now please use your imagination: without disassembling the engine like what it shows in the photo, and with the cylinder head blocking your space (you can use the right hand side cylinder in the above photo as comparison), are you able to reach the sensor and take it out, then install a new one? For other people I am not sure, but I know I cannot.

 

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