2018 BMW X1 DCT Review; More Economical, Compacter and Cheaper
BMW X1 DCT Review; More Economical, Compacter, and Cheaper: The conventional vending machine makes BMW’s front wheel actuators and Mini-place for a dual-clutch transmission. Is that change also an improvement? We take a closer look at the new bucket.
The vending machine in the first generation of the 2001 new Mini was a CVT, a push belt from the same supplier who previously put the Variomatics for Daf and Volvo together. However, in Generation Two (2006), the SC was said goodbye, favor a conventional, planetary dispenser with torque converter of Aisin. The classic vending machine has spread like an oil slick over the mini-models and is now also just right at the front of the mini-related BMW X1 DCT. Until now, because BMW and Mini come with a new vending machine, a transmission with the double clutch (DCT). This principle is not entirely new to BMW because in the M3 we have been in DCT’s since 2008. This time, however, it is a slow-track gearbox for slightly more modest motorized front wheel actuators, replacing the conventional machine with torque converter. The rear BMW just keep the familiar vending machines of ZF.
The seven DCT comes first in the X1 2.0 sDrive and the Minis One and Cooper D, both the three-and five versions of the Cabriolet. From March onwards, more potent motorized minis are also given the seven DCT, because it is suitable for engines up to 300 nm. The Cooper (136 hp and 230 nm) and Cooper S (192 hp and 300 nm) also belong to this. The advantage of the DCT is that-ie is lighter than the conventional vending machine and that it has less internal losses. This is partly due to the need for much less oil pressure, which is all beneficial for consumption (and thus for CO2 emissions).
We have the DCT first extended to the tooth felt in the BMW X1 DCT with the 192 HP Strong 2.0-liter four-cylinder. The electronics know exactly when to switch, there is no time hesitated. The switching itself is hotfix and silky. It is of the level that we are accustomed to the classic vending machine and that is sometimes significantly less in other DCT’s. The steps between the gears are nicely chosen and in the next move, the motor is kept neatly in the correct touring area. The emphasis here is on comfort. In the Sports mode, the gearbox keeps the engine more on touring, but also the emphasis remains on comfort. We have no time to feel that we want to interfere with the acceleration choice.
Basically, both the hardware and the software for the DCT in the BMW X1 DCT and the Mini alike, only the calibration is different. This is done because the Mini is lighter than the BMW and also has a sportier inches. There, the one and the zeros in the control unit take a neat account: the tuning is more dynamic and therefore runs just a little more in the past with the character of the Mini. The switching strategy is just a little different from the X1; The switching itself goes that as with that model hotfix. and also when we interfere with the acceleration choice by means of a tap against the newly designed poker, our switching command is executed immediately. For both the BMW and the Mini, it is true that the flippers are not on the menu and-according to one of the engineers from the development team has not been developed either. It is only a pity that the new poker in the Mini has become slightly shorter, so you have to move your arm further away from the handlebars.
The fact that fuel consumption has been an important reason for the switch from conventional vending machine to the DCT also shows that the switching strategy can be adapted to data from the navigation system. When approaching a roundabout or the built-up bowl, the transmission can stage the correct gear, as in approaching a slope or descent. These are such details that can make the difference.
2018 BMW X1 DCT Review – Electric VERSUS Hydraulic Switching
The DCT as used in the BMW and Minis is not BMW’s own development but comes from transmission manufacturer slow. It is in the base the same DCT that slowly also delivers to Renault, only they have poured their own sauce in Munich. This means, among other things, that the switching points have been adjusted and that the speed at which the switch is switched is slightly greater. Although we encounter the DCT at BMW and Mini for the time being in front wheel actuators, it is also possible to use it in a four-wheel drive, as long as the engine is at the front. DCT stands for double clutch transmission or a gearbox with two clutches. One clutch is for the even and the other for the odd gears. The gears for the even gears sit on its own shaft, just like the gears for the odd move. When an even acceleration is on, an odd acceleration can be staged on the other axis. If there is then to be actually switched on, it is only a matter of coupling the even gears open while simultaneous the clutch of the odd gears is closed. This happens lightning fast.
With a manual gearbox, the respective gears are inlaid by the movement you make as a driver with the acceleration poker. This movement is transformed into the gearbox into a longitudinal movement of a switching fork that allows for a connection of the gears belonging to the selected gear with the outbound axle. This sliding movement can be achieved in different ways. In the DSG’s as developed by gearboxes manufacturer BorgWarner and licensed by the Volkswagen Group, the movement is hydraulically established; A hydraulic cylinder is attached to the front and back of the rod on which the fork is located. The oil pressure in these cylinders is controlled from a mechatronic line block. This electro-hydraulic control unit is powered by an oil pump and sends (as soon as it needs to be switched) via solenoid valves the oil to the corresponding rod with switching fork. That all happens lightning fast.
Slow it up for the DCT’s of Renault and BMW in a completely different way. Instead of hydraulic cylinders and an electro-hydraulic control unit, switching rollers are used to remember what you might know about a motorcycle or car gearbox. The even and the odd gears have in the slow DCT each on such an electric motor-driven role. Each roller is fitted with a groove with a profile. A ridge on the rod to which the steering fork is attached follows that profile in the role which allows the fork to be moved back and forth. Because the profile is to be followed in the role, no acceleration can be skipped. From 7 to 3, it is not possible to let the switching fork go by 5, and on the other side, it does not go from 6 to 2 without tapping the 4. So it really works sequentially. This is not with a closed link, so as a driver you do not notice anything, it all happens without you being very much in it. Both the electro-hydraulic(VW) and the electromechanical (BMW) system work hotfix. The advantage of the electromechanical system is that only oil pressure is needed for the clutch (which is only a little bit) and not for switching, which means less energy loss in the powertrain because there is not a pump to run all the time. Furthermore, the heavy and voluminous mechatronic unit can be omitted and the correct gear can be set up without a rotating oil pump (for example while waiting for a traffic light).