BMW Z4 chassis secrets March 22, 2009Posted by Richard Aucock in Launch fever.
Tags: 2009, Alicante, BMW, Krusche E89, launch, Z4
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Heinz Krusche is BMW’s chassis guru. I’ve met him several times, and always enjoyed top insight from him (not least his tales of how he keeps DSC turned on for the road – but ‘always’ turns it off when on track…).
Such people exist in every car company, but they don’t always have the power of Krusche.
He wields the same sort of influence as Jost Capito at Ford. There’s another genial genius – and look at how well Fords drive. Lotus, too, has Matt Becker, ensuring that every model drives sublimely.
So, speaking to Krusche is always enthusing. Here, then, are five reasons why the Z4 is another tick against his name.
1. Stiff Body In White
The basic bodyshell is 25 percent stiffer than before. Vital, said Krusche, for the entire driving experience. This torsional rigidity is the starting point, the vital gear in the cog. Without such a good starting point, he said, it is impossible to make cars drive well.
‘It is a big step down if the tolerances are too great.’ You can’t turn a fundamentally bad car into a good one with tweaks alone.
2. 3 Series front axle
The new Z4 uses the 2-joint front axle from the E90 3 Series (and also the various iterations of 1 Series). It’s vital, said Krusche, not least for improving feedback to steering.
With it, BMW can independently tune directional stability, steering feel and lane change stability. Curing a major flaw of the E85 Z4: its wearisome camber steer.
The rear axle, incidentally, is a development of the old Z4 (and is also on the X3). ‘There was no reason to change it,’ said Krusche.
3. Axially parallel layout electric power steering
The new Z4 also uses the axially-parallel EPAS system from the 3 Series. It means the engine isn’t sat on the steering column, so mass is reduced and a purer feel from the road is allowed. The electric motor is in parallel to the steering rack.
The EPAS system has also allowed Krusche to tune the frequencies from the road surface. Basically, you want to isolate high frequencies, but allow through low frequencies. Cumulative learning from the old, oft-criticised Z4 EPAS has allowed BMW to do this.
‘You can vary steering torque with the switch in the car,’ said Krusche. It means it can be (over) light in normal mode, meatier in Sport +.’
He’s tuned it so there is no resistance for when you need to make steering corrections – tidying up snap oversteer, for example. ‘We also vary the feel for when you come to the limit, adjusting the Servotronic function for more feedback.’
4. Greater understanding of run-flat tyres
The E85 Z4 was a run-flat pioneer, and earned much criticism for being so. The tyres’ necessarily stiff sidewalls, and greater weight, both counter ride fluidity. Almost a decades’ learning, plus BMW’s close collaboration with tyre maker Bridgestone (the rubber’s bespoke for the new Z4) mean big improvements.
The evidence of this learning is illustrated by driving the E60 5 Series alongside the newer E90 3 Series, for example. But for greatest contrast, feel how the E85 and E89 Z4s deal with impact harshness and sudden surface imperfections.
Krusche makes a further revelation here, though: again, close work with the Body In White team has led to yet more improvements. By working out the intricacies of where run-flats need compliance in the structure, and where they’ll benefit from extra stiffness, BMW’s been able to tune and filter the natural frequencies of the bodyshell to dramatically improve ride quality.
It’s all about incremental understanding, he said.
5. Change in BMW setup philosophy
Since the 1 Series Coupe, BMW has subtly tweaked its basic chassis setup to improve comfort. Spring rates are slightly softer, and dampers a little stiffer. This has been influenced, again, by knowledge from the characteristics of run-flats.
The secret to doing this well, says Krusche, is in damper tuning. By playing with internal baffles, the size of the holes within them, the rates of flow between the three internal champers – goodness, even the material of the plunger on the strut! – depth is engineered in. Fine art? Call it black magic…
Despite all this, though, Krusche says he doesn’t get the final sign off. It’s always down to the BMW Board – who, at least thrice a year, will drive test cars and give the final say-so.
Krusche can only do so much. The final Z4 we drove on the launch was not one chosen by him, but the good Dr. Ings. You have to say, all have not done a bad job…
NEW: BMW Z4 photo stream on Flickr March 21, 2009Posted by Richard Aucock in Launch fever.
Tags: 2009, Alicante, BMW, launch, Z4
Want to see what I’ve been up to on the BMW Z4 launch? Well, check out my Z4 photo stream on Flickr.
And be sure to come back here over the next few days, as I plough through all my notes and feed back to you…
… clicking on the images should give you a taster, though!
Pre-launch impressions: BMW Z4 2009 March 21, 2009Posted by Richard Aucock in Pre-launch impressions.
Tags: 2009, Alicante, BMW, E89, launch, Z4
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Sitting on the plane, going through the press information for the Z4, writing this, I’m really rather intrigued.
See, I have a fair impression of what this car is going to be like. Fast, very crisp and agile. Sublimely cultured and smooth. Bigger and more grown up than the old one. And, vitally, smoother riding.
I don’t expect it to have lost the original’s alacrity and rear-balanced precision. Indeed, I expect this to be enhanced, as there’s surely no way the new one can tramline and follow the road surface as badly as the old?
And, with the improvement in ride quality, it’s going to be a much easier car to drive on rough surfaces.
There should be a sat-back, powerful feeling, judging by how close the seats are positioned to the rear axle. That will be enhanced by an engine I adore – the 3.0-litre twin-turbo. 306bhp, 62mph in 5.2 seconds… it’s just dawning on me how fast this is likely to be.
Negatives? Well, I reckon they could have done more with the interior which, apart from a Z8 style centre console, lacks the special style of Audi’s TT. The instrument panel also looks a bit cheap, still, despite apparent improvements elsewhere.
Back to ride, though. They’ve got to, got to, have improved it, surely? In fact, I can guess they have. The press pack tells me the optional electronic damper’s stiffest setting is only as stiff as the old car’s standard set-up…
I have doubts over the price, though. The sDrive35i I’m driving today is £4400 dearer than the sDrive30i – that car’s almost as fast. What are the benefits of the sDrive35i? I’ll be grilling them to find out the intricacies.
My aim now is to always record these pre-impressions, then to see how the reality fares. You can follow my thought processes, and any preconceptions I take into the road test, for a more accurate representation of how a car actually is.
France goes digital – soon! March 21, 2009Posted by Richard Aucock in What randomly caught my eye today.
Tags: 6Music, BBC, DAB, digital, France, George Lamb, radio
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I’ve got an in-car digital radio; it’s so awesome, I’d never be without it. This boy, he don’t need much.
Made by Pure, it works a bit like Griffin’s pioneering iPod transmitter – transmitting a low-power signal that the in-car stereo, tuned to the specified ‘blank’ station frequency, can pick up. All for £60.
It’s faultless, and means I can have BBC 6Music wherever I drive.
I need this aftermarket add-on, though, because in-car DAB is still virgin territory. Despite being available for years now, few makers have picked it up. It’s still a rarity, even in the high-spec test cars we sometimes get in the Motoring Research office.
Things are about to change, though. In a surprise move, the French Government has made it law that all cars from 2013 must have standard DAB digital radios. Wow! That’s one way of imposing a digital switchover…
It’s certainly caught the industry on the hop. Standard on few, barely 20 percent of new cars offer DAB even as an option – and it usually costs £300 or more where it’s offered.
This means that standards are fragmented across Europe, too. Each country uses different digital bearers, which makes developing, for example, the successor to RDS TMC traffic reports – TPEG – hard.
France’s move is admirable, but the risk is that standards are rushed through that aren’t compliant with other countries. Could Britain risk missing out? It will be up to regulators over here to respond fast to France’s move, to ensure we’re not.
In the meantime, I’ll bear the faff of juggling mobile phone charger with DAB power socket in the 12v socket, if it means not missing George Lamb… yyyyyea!!
What I learnt… from Fleet News, 20 March 2009 March 20, 2009Posted by Richard Aucock in What I learned today.
Tags: Fleet News, Government, green, sales, scrappage, SMMT
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So far, new car sales have fallen by 28 percent. The new car market is predicted to fall from over 2 million new car sales, to 1.7 million sales, or less.
Yet the SMMT says it could be boosted by 250,000 sales in an 18-month period by a new car scrappage scheme.
It would have to incorporate nearly new green cars to be of any benefit, though, a leasing company boss told Fleet News. Surprisingly, he said this would have to cover cars up to four years old.
This would stimulate the used car market and thus boost the new car market.
But, isn’t the used market already thriving, as buyers seek extra value? Aren’t car auctions seeing record results and a shortage of stock? I think he’s barking up the wrong tree here.
… Fleet sales once accounted for over half the new car market. Now, due to the recession, it’s down to 44.8 percent. Retail sales are, relatively, booming, taking 55.2 percent.
This is despite reports that retail customers are sitting tight, waiting for the Government to decide on a scrappage scheme. If it comes, I’d expect the proportion to become even more skewed.
… Those fields of cars we keep seeing on the news are just an illusion. Actually, fleet bosses say, there are not loads of cars sitting ready to go. So, huge fleet discounts are not on the table. One chief told Fleet News that swingeing cutbacks by car makers last year have slashed inventories.
… Car makers making the best of the recession include Ford, whose market share is approaching 20 percent – a massive increase on 15 percent last year. French makers are struggling, though. Citroen has 2.8 percent, Peugeot 3.8 percent (down from 6.1 percent) and Renault just 2.7 percent (down from 5.7 percent).
Secrets of the new Toyota Prius March 20, 2009Posted by Richard Aucock in The minutiae of cars.
Tags: economy, Geneva, Golf, green, Hybrid, Prius, Toyota, Volkswagen
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I was honoured to speak with the chief engineer of the new Toyota Prius, Akihiko Otsuka, at the Geneva Motor Show recently. Honoured, because the young dude is quite a guy.
Oozing enthusiasm for the Prius, his groundedness and sheer enthusiasm wowed me. We’re close in age, he and I, and I really felt how ‘here and now’ he is. Think everything that’s dynamic and invigorating about modern Japan, for an idea of his approach.
This whirlwind of ideas shows in the new car, which really is quite something. Official fuel economy of the current one doesn’t always carry through to reality, I said. Unbowed, he admitted so – a key target of the new car was to improve on this.
He told his team to benchmark against the Volkswagen Golf 1.9 TDI – not the default 2.0 TDI, which is a fair bit less efficient. Quite a challenge, as I know how economical that engine can be. But Otsuka ‘beat it’.
A new approach to body design helped here – he allowed the aerodynamic engineers to work with clay models, ‘despite the expense’. This is unheard of in the car industry, where stylists normally hold sway. But, getting aerodynamics engineers so closely involved in the shape means the drag factor is a startling 0.25. An old Mini, by way of comparison, is 0.56….
However, while the hybrid gear is the big deal, he admits that this contributes only half to the overall 14 percent economy improvement. The other 7 percent?
‘Low rolling resistance tyres, aerodynamics and other energy improvement methods.’ The same, in other words, as employed on a VW BlueMotion, Volvo DRIVe, Ford ECOnetic, SEAT Ecomotive…
This fact brings home the law of diminishing returns. And the scale of the challenge car makers face in making cars continually more green.
I have an absolute mass of information from the discussion, which I’m using to write a piece for Automotive Engineer magazine. Overall, though, meeting Otsuka-san was quite something. In a month or so’s time, we’ll be finding out if his car is as good.
What I learnt from Autocar – 18 March 09 March 19, 2009Posted by Richard Aucock in What I learned today.
Tags: Autocar, Citroen, Jaguar, Mercedes, Mini, Saab, Volkswagen, Volvo
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… I saw a heavily cloaked test car a few weeks ago on the M42. Looked like a Jaguar, beneath the disguise. It was – the new XJ, which Hilton says will be unveiled in June.
It was going to be a reskin of the current model, but is much more than that. Jaguar’s taken the lessons from the XF – a rehashed S-Type – and applied them here, for an extensive overhaul using the same air-suspension wheelbase.
Styling will wow. Jaguar designer Adam Hatton stressed as much over a beer late last year, at a function in the Cotswolds… and I believe the Malvern-dwelling dude (who rates the Citroen C4, but doesn’t like the new MINI).
There’s even going to be an all-glass panoramic roof.
Jag’s 3.0-litre V6 diesel will feature: this is so powerful and eco, it makes the V8 diesel redundant. Range Rover only for that, then? Seems an expensive way of doing things.
… VW’s said it’s planning a Bluesport range of green performance cars. Like Bluemotion, but faster. Raking in more profits, then.
… Mercedes will sell a diesel version of the next SLK, due in two years. As it’s based on the fine current C-Class platform, expect the brilliant C 250 CDI engine to feature.
… Sweden is not to ban petrol and diesel in 2020. It will ban them in 2030 instead. So that’s why Saab and Volvo are so big on biofuels…
More on the mighty Alpina D3 Bi-Turbo March 18, 2009Posted by Richard Aucock in What I learned today.
Tags: Alpina, BMW, Car Dealer Magazine, D3 Bi-Turbo, MSN Cars
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Matthew Kidd, sales chief for Alpina GB, dropped me a line after reading my post on the new Alpina D3 Bi-Turbo. It’s even more of a machine than I first thought!
As he says, ‘this is no simple chip-tune’. Engine software, for example, is completely bespoke to Alpina – written from scratch by the tech guys, and downloaded into the car on the regular BMW production line.
It even has its own engine wiring loom.
All this is why the 123d’s 2.0-litre twin-turbo enjoys such a power boost. But, here’s something: the bigger Bi-Turbo actually weighs less than the 123d! What’s more, at 1480kgs, it’s also 25kg lighter than the 325d.
Where it matters: up front.
It also has those distinctive big Alpina wheels, but they hide far more besides. The suspension comprises:
· Stabilisers from M Cars
· Secondary springs from the 335d
· Unique camber, caster and rolling radios
· Unique primary springs
· Bespoke settings for each variant – saloon, Touring and Coupe D3
Less than 100 saloons will be sold a year. The Touring and Coupe will be even rarer – ‘just a handful’.
When I can get up there, look out for more on how it fares on the road!
What I learnt… from Autocar, 11 March 2009 March 18, 2009Posted by Richard Aucock in What I learned today.
Tags: Audi, Autocar, Golf, green, Lamborghini, Mercedes, Mini, Renault, Volkswagen
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… Top VW product man Ulrich Hackenberg says customers are prepared to pay more for Bluemotion ‘green’ cars. That’s because they’re 5-10mpg more economical. Win-win for VW, then. It gets more cash for each car, which customers are happy to buy in decent numbers.
With such a business model, why would it thus apply the Bluemotion changes to all models, cutting such a profitable revenue stream?
VW’s rivals may snipe and say that ‘all our cars are green, not stand-out green specials’ – but they ‘aint getting the profits of VW. That’s why Bluemotion’s here to stay.
Hackenberg also says customers are understand that they must look at engine technology, not size, to gauge performance. Good news for the downsizing trend.
… Next year, MINI will start selling patterned soft-top Convertibles. Not easy to productionise down at Oxford, but extremely lucrative, I’d have thought.
… Renault reveals the Megane Renaultsport 250’s carryover platform has been re-engineered to take a short-shift 6-speed gearbox. Why go to the trouble? Unless there are future transmission developments we’re not aware of…
… The Golf R32 will lose its heavy V6 for a more eco four-pot turbo. Probably the TTS’s 268bhp unit. It’s for handling as well as emissions, says VW.
… the origins of the TTRS’s five-pot turbo are revealed. It’s actually a tuned-up version of an engine seen in the US-spec VW Jetta. Not, as Audi claims, half a Lamborghini V10. Ahem.
Social media brings close access to heroes! March 17, 2009Posted by Richard Aucock in What I learned today.
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Social Media is all about community, relationships and helping one another out. So, after days puzzling over my WordPress site layout, I had to admit defeat…
Help!, I asked Brendan. I can’t get flaming subscribe-to-feed tags into my blog profile – and they’re a must-have. Any tips?
Brendan came straight back with the answer four days of internet searching had failed to resolve. Succinct, on the money and just what I needed. And then, when I came across another grumble, I cheekily sent another e-mail: result? He was straight back, with two lines of aid that, when I enacted them, roused a cheer you could hear in Cherbourg.
Now, we’re all linked up – so do please follow me, if only to repay some of the effort that’s gone into it! – and I can only salute once again the brilliant Brendan Cooper. A true hero.
Coffees are on me next time, I’ve promised…