Difference in the handling?
- Thread starter 2dogs
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The coupe has a stiffer body, so it will handle a little better on the track. I doubt that most of us would ever notice a big difference on regular streets.2dogs said:I have seen that some of you out there have owned a soft top and a coupe.
Did you find much differents in the handling and over all ride between the two models.
the roadster is lighter because unlike most coupe/convert cars the zed was designed as a roadster to begin with. Making it a coupe added some weight albeit made it stiffer too.
ive driven both, but the coupe was about a year before i owned my roadster so I dont even remember the difference.
ive driven both, but the coupe was about a year before i owned my roadster so I dont even remember the difference.
:exitright:
Boxster and Z4 are unusual in developing Coupes from roadsters. Seems the right way to go as all the roadster versions of coupes look lardy-assed and not a patch on the tin top version. I'm thinking TT, 350Z,even the 911.
Roadster or coupe? Well they both handle very well and you would have to be on a track to notice any difference. Still when it rains you can put the roof up on the roadster but when it's sunny you can't take the roof off the coupe
So it's a roadster every time for me 
Roadster or coupe? Well they both handle very well and you would have to be on a track to notice any difference. Still when it rains you can put the roof up on the roadster but when it's sunny you can't take the roof off the coupe
So it's a roadster every time for me They both handle well. My previous Z4R sport package with PS2 can keep up with almost any car on the twisty. I have a Z4MC now so its not a fair comparison. The short time I have OEM suspension I thought Z4R with sport package give me more confidence. That's probably because I know the car better. The roadster will suffer when you get over 120 mph with the top down.
I'm sure the differences between roadster and coupe are very marginal wheras the difference between those with/without ///M sport suspension will be much bigger, as will the run flat or not tyre choice
I have read somewhere that the torsion stiffness of the chassis in both cars is virtually the same, this is because the original chassis of the roadster is taken to create the coupe and therefore there is no need for any changes due to all the chassis strength being there already, it also said that in theory you could cut the roof off the coupe and it would drive ok as you would not be removing any of the chassis's rigidity. This is not the way of a car that was designed the other way as the roof is a structural part of the car hence alot of chassis work has to be done to strengthen it hence a weight increase.
I did find this from an article online addressing the M versions,
"Scoring 14,500Nm/degree in BMW’s torsional stiffness test, the M Roadster is pretty stiff for an open car, and despite its wide 225/45 and 255/40 rubber on 8.0J and 9.0J x 18-inch alloys rubber, scuttle shake on poor roads in minimal. Even so, it does not come close to the Coupé’s impressive 32,000 Nm/degree, which is more than double the Roadster’s rigidity."
Its hard to believe that its over 2x more rigid, but I guess the roof does a lot.
"Scoring 14,500Nm/degree in BMW’s torsional stiffness test, the M Roadster is pretty stiff for an open car, and despite its wide 225/45 and 255/40 rubber on 8.0J and 9.0J x 18-inch alloys rubber, scuttle shake on poor roads in minimal. Even so, it does not come close to the Coupé’s impressive 32,000 Nm/degree, which is more than double the Roadster’s rigidity."
Its hard to believe that its over 2x more rigid, but I guess the roof does a lot.
Yep I recall this discussion previously, it is definitely about twice as stiff, I thought the roadster was 16000 though.
I can believe it though, my Z4 roadster use to squeak, rattle and roll relentlessly, whereas no other hatch/coupe I have owned ever did that, even my Fiat Panda
It all adds to the charm of having a roadster though.
I can believe it though, my Z4 roadster use to squeak, rattle and roll relentlessly, whereas no other hatch/coupe I have owned ever did that, even my Fiat Panda
It all adds to the charm of having a roadster though.
bmwmike said:
...it's because the roof isn't bolted on like a removable hard top, it forms an integral part of the structure via the A and C pillars creating double the 'bridging' (for want of a better word) between the front and rear of the car....Picture a rolled up newspaper between your hands and twisting each end in opposite directions. Now do the same if you fold than newspaper over on itself so it's twice the thickness. It wil be much harder to twist?
Bess analogy I can come up with anyway LOL