RE: BMW 4 Series Convertible: Review
Discussion
A lot of favourable comments on the E46 on here (a car I do like, it must be said), and a lot of comments on the E93 being "wobbly".
It should be noted that, for anyone who cares about reality, it seems from the information I've been able to find the E93 (that is, convertible, derided as wobbly), is significantly stiffer than the E46 (the coupe version, universally praised).
It should be noted that, for anyone who cares about reality, it seems from the information I've been able to find the E93 (that is, convertible, derided as wobbly), is significantly stiffer than the E46 (the coupe version, universally praised).
May be so when you have the roof up. Roof down, no way - and shifting all that weight backwards will change how the front end behaves for the worse. I'm not saying the E46 is perfect, it isn't and I hated mine (318i Touring, slowest most gutless useless heap I've owned since I inherited my mother's Volvo 340!). I just do not like the whole idea of a folding hardtop convertible.
Why would opening the roof change the front-end for the worse? One thing I'm not a far of with most BMWs is the weight distribution - 50% over the nose is too much for my preference. Opening the roof moves the CoG backwards and downwards, both of which are good in my book. Of course it will also raise the polar moment of inertia a bit, which isn't so good.
kambites said:
Why would opening the roof change the front-end for the worse? One thing I'm not a far of with most BMWs is the weight distribution - 50% over the nose is too much for my preference. Opening the roof moves the CoG backwards and downwards, both of which are good in my book. Of course it will also raise the polar moment of inertia a bit, which isn't so good.
You put the weight of the roof further back, you're moving away from the 50:50 weight distribution - and, while you can set a car up for its weight distribution, short of active suspension, you can't tune it for two significantly different weight distributions. Oh, and BMW have less weight over the nose than most of their rivals (especially Audi!).Amirhussain said:
g3org3y said:
Amirhussain said:
Wills2 said:
Bungleaio said:
RoverP6B said:
The E92 was a fixed-head coupe. The E93 was the wobbly poser's blancmange.
As an owner of an E93 I would say it is far from wobbly, yes occasionally there is some vibration but it's not often.For me a folding hard top convertible is the best of both worlds and mostly people that I've had in it (that aren't really into cars) have no idea that the roof can go in the boot. I've covered a good few miles in mine in the past year both roof up and down and it's a great car, personally I can't see me changing cars for a good few years, the cost of the 4 series is far to high to justify the change at the moment plus I'm loving the NA straight six, an option that I doubt will be available in the 4
I'm not going to get into a convertibles are for posers argument, you either get it or you don't.
All went downhill after that.
RoverP6B said:
kambites said:
Why would opening the roof change the front-end for the worse? One thing I'm not a far of with most BMWs is the weight distribution - 50% over the nose is too much for my preference. Opening the roof moves the CoG backwards and downwards, both of which are good in my book. Of course it will also raise the polar moment of inertia a bit, which isn't so good.
You put the weight of the roof further back, you're moving away from the 50:50 weight distribution - and, while you can set a car up for its weight distribution, short of active suspension, you can't tune it for two significantly different weight distributions. Oh, and BMW have less weight over the nose than most of their rivals (especially Audi!).RoverP6B said:
kambites said:
Why would opening the roof change the front-end for the worse? One thing I'm not a far of with most BMWs is the weight distribution - 50% over the nose is too much for my preference. Opening the roof moves the CoG backwards and downwards, both of which are good in my book. Of course it will also raise the polar moment of inertia a bit, which isn't so good.
You put the weight of the roof further back, you're moving away from the 50:50 weight distribution - and, while you can set a car up for its weight distribution, short of active suspension, you can't tune it for two significantly different weight distributions. Oh, and BMW have less weight over the nose than most of their rivals (especially Audi!).Lets be honest, the 4-series is hardly going to be the sharpest of driving tools any form, let alone the cabriolet.
Edited by kambites on Tuesday 18th February 16:53
jdw1234 said:
Would you really notice on a sunny Sunday afternoon, roof down on your way for a pub lunch though
On the roads round here, I'd certainly notice the loss of rigidity. Even my 5-series Touring can be felt to flex a little on arguably the worst (well, most challenging) B-roads in the country. I would also definitely notice the front end going light.RoverP6B said:
redroadster said:
Yes they will sell loads, german cars are what most people aspire to hence why germanys economy is so strong look at france with citroen ,renault,peugeot.........
That's an extremely simplistic and inaccurate view of why Germany's economy is healthier than France's.kambites said:
Of course, but for me perfect weight distribution for a RWD car is about 40:60 F:R so it will bring it closer to that. As for how the suspension is setup, who knows whether it's designed primarily for roof up or roof down - I suspect it's a compromise of the two. I very much doubt I'm a good enough driver to tell the difference made by moving 50 odd kg backwards and downwards a couple of feet in a 1.8 tonne car anyway.
Lets be honest, the 4-series is hardly going to be the sharpest of driving tools any form, let alone the cabriolet.
How is an unbalanced weight distribution better than a balanced one? Next thing you'll be telling us Porsche have been wasting their time pushing the 911 flat six ever further forward and putting more weight in the front... a 4-series coupe could actually be quite a nice thing to drive, but Christ, a 1.8 ton folding hardtop convertible thingy... no way!Lets be honest, the 4-series is hardly going to be the sharpest of driving tools any form, let alone the cabriolet.
Edited by kambites on Tuesday 18th February 16:53
kambites said:
Turn that on its head. Why is it "perfect" to have half the weight over each set of wheels. The two axles aren't performing the same roles.
Light nose, heavy arse: overlight steering, pendulum effect, lift-off oversteer.Heavy nose, light arse: heavy steering, understeer, poor traction if it's RWD, possibly also lift-off oversteer.
You didn't answer the question. Obviously there needs to be a balance but why is that balance 50:50?
In (non road-car based) racing cars in series where the weight distribution is unlimited but the cars can only be 2WD, what weight distribution do people go for? You can bet it's not 50:50.
In (non road-car based) racing cars in series where the weight distribution is unlimited but the cars can only be 2WD, what weight distribution do people go for? You can bet it's not 50:50.
RichB said:
g3org3y said:
I just had this delivered to my work today (I get all my models delivered to work!)
That's really nice. Was it built for you to that spec? Nothing 'special', standard AutoArt (Millennium) model. Obtained from eBay.
Will match up nicely with my other AutoArt 328 Mille Miglia that I bought a couple of weeks back.
Back OT, apologies folks...
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