BMW X6M suspension secrets July 25, 2009
Posted by richard in : Technology , add a commentSTANDARD BMW X6 models, in corners, work harder, earlier, for agility.
And that, explains Head of M Development Albert Biermann, is down to how the clever torque vectoring rear axle is programmed: power is shuffled round quite considerably, to give a rear-steer effect and kick the back end into corners.
The X6M uses this same technology – but is more linear. ‘It is not as agile, so we don’t work the rear end as much early on.
‘However, once you’re within the corner, we engage it far more – here, the split happens much earlier than in the standard X6.’
Why? ‘So the driver can get on the throttle earlier.’ And feel the ‘rear drive’ balance M reckons is a characteristic of its cars.
It’s not only here where the ‘M-gineers’ (arf) have been busy. ‘Dampers and springs are stiffer – and there are bespoke EDC settings. The ABS and Dynamic Drive are specially adjusted – the stiffness of the roll bar goes hand-in-hand with the dampers.’
There are stiffer upper wishbone hearings, and stiffer rubber in the rear axle carrier. ‘This gives better off-centre feel and more precision.’ The engine mounts are stiffer, too.
‘The upper shock mounts are also completely different.’ This solution, says Biermann, was very expensive, and could be easily overlooked. It shouldn’t be.
In the standard X6, there are three components, all settled together in the upper mounting. This sees the helper spring and damper share a common rubber bearing.
It’s a compromise. The helper spring is offsetting the rubber bearing over a spring, for example.
So, with the X6M, we’ve separated the bearing and piston rod from the helper spring. This means the two bearings fit better together; and one is dedicated to the damper, the other to the helper spring.
Advantages? Considerable, especially over challenging roads. It’s particularly good for comfort – it’s at least as good as the regular X6…
BMW Z4 has 3 Series Convertible to thank
How do you make a BMW X6M? July 20, 2009
Posted by richard in : Technology , 1 comment so farBMW X6M. Or, but for Mazda, the MX6. What in Lord’s name is it all about, ask hardcore M fans worldwide.
Well, it was certainly a challenge, admits M Head of Product Management, Carsten Pries.
‘M cars,’ he revealed, when asked about the process of the X6M’s creation, ‘must display the core values of the brand.’
Which are?
According to our man Pries, M cars must be best in:
• Acceleration
• Lateral dynamics
• Efficiency
• Steering behaviour
• Braking distance
He admits they weren’t sure the X6 could be made suitably ‘M’ at first. The department eventually figured it could – but it wouldn’t be simply a matter of making a big M3.
‘Customers in this segment are different to M3 buyers. We thus had to define in the early stages exactly what these new needs were.’
An SAV, he says, is ‘completely different’, particularly in terms of size and weight. It is therefore vital to develop a good sense of the key requirements.
Which are not the same as an M3, whose buyers are ‘deep into technology – they go into dealers and give them a hard time with their in-depth knowledge! They know so much…’
So what about these M SAV (or, as the rest of the world prefers, ‘SUV’) buyers? ‘They’re performance orientated, but not that into the last technical detail. They want high performance, and a differentiated character in terms of suspension, chassis, steering and design.
‘It needs to be dynamic, easy to control, have a clear emphasis on rear-wheel drive.’ M-lite, if you like. M with bling, you could also say.
See, it is vital the model is highly exclusive – a particular requirement for this segment. ‘It must stand out, be instantly recognisable as something different to an xDrive50i. It should be seen as being the latest, the most powerful. It’s also not a car for people who just like to pretend. Form must follow function. ‘
What Pries means here is that it should not be merely chavv’d up. A no to show without go.
There was another consideration, too. ‘It was vital we didn’t compromise its off-road ability. People want to take these to the Alps – if we restrict this in any way, it will not be as successful as we wish.’
No wonder it took them two and a half years to develop.
Along the way, he ditched potential grumble-areas. BMW M drivers, it seems, don’t like Active Steering. Their power steering systems have to be consistent. That’s why M spent big developing a bespoke Servotronic steering system for its most expensive X SUVs.
Servotronic means variable weight – it’s light at low speeds, weightier at higher speeds – but the steering ratio is consistent.
‘We intentionally didn’t use Active Steering – the steering angle must be consistent whatever the road speed,’ says Pries. ‘This is appreciated by our sports car drivers…’
There it is again. Sports car drivers. BMW’s thought long and hard about this one, about whether an SUV can actually also be an M. It reckons so.
Me? The jury’s out…
BMW Z4 has 3 Series Convertible to thank
BMW tells me why its instruments are lit in orange
BMW LCI not ASAP for M July 18, 2009
Posted by richard in : Minutiae of cars , 1 comment so farBMW facelifted the 3 Series last year. Odd, how M hasn’t followed with the M3. Why’s that?
Well, it’s because M has such independence from BMW AG.
It’s able, says Head of Product Management Carsten Pries, to make deliberate decisions separately from mainstream BMs
‘We launched the M3 in March 2008,’ says Pries. ‘In September, AG launched the LCI (life cycle impulse) 3 Series. We didn’t follow, keeping instead the same existing front end.
Why? ‘Because we didn’t think it was necessary.’
The M3, says Pries, is suitably differentiated from the 3 Series not to need the additional expense of an (admittedly subtle) LCI so soon into its like. ‘We carried over the revised design tail lights, that’s all.’
This independence, he adds, comes through M being so well integrated into BMW AG. It can make unilateral decisions 12, even 24 months ahead, as it did in this case.
‘It’s exciting to do LCIs – as with the M6 Competition – but if it’s not necessary, we won’t automatically do it.’
Purity and purpose, rather than marketing for marketing’s sake. That’s M. Now, the X6M…
BMW Z4 has 3 Series Convertible to thank
BMW tells me why its instruments are lit in orange
What Porsche gives to BMW M April 23, 2009
Posted by richard in : Minutiae of cars , 6commentsBMW’s M3 is the core of the M brand, Rolf Sheibner from the division told me.
So who is its closest relative? Step forward the Porsche 997 911. Yes, really. ‘In terms of dynamic skills and character, the M3 and 997 are like relatives,’ Sheibner revealed.
Well, I’ll be.
He was straight up, though. The M division hadn’t benchmarked the M3 against other M cars, but the mighty and ever-better Porsche, the definitive everyday supercar.
‘For 30 years, M3 customers have also been drawn to Porsche. When someone considers one, they’re usually looking at the other, too.’
Which presents quite a high bar for the M division to clear. That’s why they start early. Albeit, from a solid base.
‘We let the road car division develop the standard 3 Series for two years. And, once they reach a certain level, we then start to develop the M version.’
Makes sense. So how much independence do they have here? A wry smile from Sheibner. ‘Look in our papers: we’re a maker! We’re called M GmBH…’ All that was missing here was the cheeky wink.
He knows his customers pretty well, though. I asked about the eight million different settings for the V8 M3’s suspension, engine mapping and whatever else. How on earth will customers get their heads around it?
‘They will play at the beginning,’ he said. ‘But then, after 3 weeks, they’ll probably leave it, happy that they’ve explored enough.’
Hence the importance of getting the standard setup right – and why there will always be a degree of computer reprofiling as per driving conditions here.
Even if customers can’t be bothered prodding buttons, there still needs to be some reward for the money spent…
BMW tells me why its instruments are lit in orange
Porsche makes cranky Cayenne cool
