BMW M52TU engine

Pictured above is a lovely, creamy inline 6 cylinder that powers my father's E46 320i M Sport. By far one of my favourite engine configuration to date thanks to its impeccable smoothness. Give the throttle a light prod, all 6 cylinders work together to provide a chauffeur smooth, yet satisfying acceleration. Well, I digress. That engine in the above photo is the M52TU. So, what is M52TU then?

M52TU is basically a variation of BMW M52 engine family, meaning it is still an inline 6 DOHC 24v with aluminium block (with the exception for North American models that used iron block instead thanks to their high-sulphur fuel). What sets apart the M52TU from the regular M52 is the former is a much enhanced version of the latter (TU stands for Technical Update). This entails the addition of features such as Dual VANOS and DISA valve.

VANOS refers to BMW's proprietary variable valve timing system. The system exists in two iterations: (1) Single VANOS (varies intake valve timing only) and (2) Dual VANOS (varies both intake and exhaust valve timing). Single VANOS is used in the regular M52 engine; the more advanced Dual VANOS is used in the enhanced M52TU engine, as found in my father's E46 320i M Sport. The advantage of Dual VANOS over Single VANOS is continuous adjustment of valve timing. In other words, it is not an on/off switch where variation in valve timing takes place over discrete steps (i.e., retard intake low rpm, advanced intake high rpm and back to retard as rpm lowers). From my understanding, Dual VANOS offers greater flexibility in choosing the most appropriate valve timing rather than sticking with Single VANOS restrictive stepped-setting. Theoretically, this further improves performance and efficiency over the M52.

Another addition to the M52TU is the DISA valve, BMW's lingo for variable length intake manifold. It adds a butterfly valve inside the intake manifold that opens and closes to create a dynamic effect of long and short manifold for better cylinder filling over wider rev and load range. In conjunction with Dual VANOS, it should theoretically aid the engine in delivering the potent performance and efficiency that improves on what the M52 is capable of.

Sounds like the M52TU trumps the M52, but does the M52TU really offer significant improvement over the M52? Lets take a look at the performance curve below:

Source: http://www.bmwtech.ru/pdf/e46/ST034/9%20Engines.pdf 

It turns out it doesn't make much difference peak torque-wise. Both M52 and M52TU output the same peak torque, but the latter peaks earlier than the former (3500 vs 3950 on the M52). Also, power peaks at the same 5500 rpm but with slightly more power for the M52TU (170 vs 168 on the M52).

The addition of Dual VANOS and DISA valve does not really do much to increase peak torque value. As suggested by the above curve, what they do instead is increase low-end torque. From the above curve, the M52TU exhibits much higher torque at low rpm and increases all the way until it reaches peak torque rpm. In contrast, the M52 has a slight bump roughly between 2000-2500 rpm and more obviously, significantly less low-end torque than the M52TU. Eventhough the M52's torque peaks at higher rpm compared to the M52TU, the curve shows that the area under the curve at the M52TU's torque peak is much larger compared to the area under the curve at the M52's torque peak. Essentially, the M52TU still has the edge as torque dips at almost the same rate for both the M52 and the M52TU.  

On the power front, the superior low-end torque garners higher low-end power for the M52TU, albeit the area under the curve is smaller. Power peaks at the same rpm for both engines, but slightly higher for the M52TU.

Overall, the addition of Dual VANOS and DISA valve do improve performance if you are looking for fatter torque curve. If peak value is what you are looking for, then it is a moot point as there is not much difference in peak torque and peak power.

That's about the detail I am able to cover in this post. If you want more details about the M52TU engine, click on this link: http://www.bmwtech.ru/pdf/e46/ST034/9%20Engines.pdf

Autonomous cars

Source: http://abc7chicago.com/automotive/ntsb-driver-killed-in-self-driving-car-was-going-9-mph-over-speed-limit/1444006/

Unless you have been living under the rock, you have probably heard of autonomous cars getting into an accident. One accident involving the semi-autonomous Tesla Model S unfortunately led to the fatal death of Joshua Brown, the owner of the ill-fated Model S, when his Model S drove underneath a tractor trailer making a left turn. Apparently, Brown's Model S failed to detect the trailer, as observed by Tesla, "Neither autopilot nor the driver noticed the white side of the tractor-trailer against a brightly lit sky". As a result, the Model S failed to apply the brake and hit the trailer's underside, ripping off the Model S roof, consequently killing Brown.

Source: https://www.google.com/selfdrivingcar/where/

Another accident involving an autonomous car is a Google car which struck a bus trying to switch lane. As highlighted in an article by ExtremeTech, the vehicle being tested, the 2012 Lexus RX450h, thought the bus would give way. In contrast, the bus driver also thought the Lexus will give way. Result? Neither of them budge and they came into contact, damaging the Lexus front left fender, wheel, and driver side sensor.  

What do the two incidences entailed then? Does this mean the claim autonomous cars are safer than human drivers are dubious? Before we go in with guns blazing thinking cars that drive itself around are 4-wheel deathtrap, we should take a deep breath and look at the bigger picture.

Autonomous cars are still at its infancy. More R&D is still on the card. Meaning, it will take years before the software improves. As a comparison, even automatic transmission technology took several years until it becomes impeccably refine in the present day. What used to be a sluggish and fuel guzzling 'slush box', the technology has improved so much that it is not just more fuel efficient than the manual transmission, but also enhances a car's performance level above what the manual transmission used to offer.

If automatic transmission technology can improve, surely autonomous cars can do the same. With some software tweaks, autonomous cars will be able to do what it fails to do today.

In the present state, there may be some negative perception about the credibility of autonomous cars, but with time, autonomous cars will improve so much that it can recognise wide range of road obstacles at every angle.

BMW F10 5 series bowing out with a bang, with the M5 Competition Edition

Source: www.press.bmwgroup.com

Like everything in life, there is the beginning and the end. The same rule applies to cars. Once it reaches the end of its generation, it ceases existence, and a new generation model takes over its place. In the case of the BMW F10 generation 5 series, its end is drawing to a close, with the next generation G30 and its high-performance F90 M5 alter ego slated to take over. But, it would not be a muted farewell as Munich wants to give a special valediction to the F10 series, in a form of BMW M5 Competition Edition.

What better way to close the F10 chapter, other than giving it an extra boost of power to its wonderful 4.4 litre TwinPower Turbo V8. Thanks to recalibration of boost pressure, 600 hp and 700 Nm overall output is yours to play, up from 560 hp and 680 Nm. Result? 3.9 second 0-100 kph time, a good 0.5 second quicker than the non-Competition Edition M5. Before being consigned to the history book, it is a good idea to leave unforgettable performance figure that makes the car meaningful.

Source: www.press.bmwgroup.com

It wouldn't be a perfect send off if you end up in the ditch somewhere. So, BMW outfitted an uprated spring, an electronically controlled damper and a thicker stabilizer bar courtesy of the M Competition Package. Also, carbon ceramic brakes housed within the 20-inch 7 double-spoke alloy wheels ensure the farewell party doesn't end with mangled metal for our F10 friend.

Only 200 units are available. Colour wise, there are 2 available colour schemes: Carbon Black and Mineral White, with 100 units each getting either colour schemes.

With the F10 on its way out, hopefully the upcoming G30 and F90 M5 will be even better.

Source: www.press.bmwgroup.com