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Why does the 35is speedo stop at 160mph?

Specific discussion about the E89 2009 Z4 (sDrive35is, sDrive35i, sDrive30i, sDrive23i)
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chasBMW
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Why does the 35is speedo stop at 160mph?

Post by chasBMW » Fri Jul 21, 2017 1:14 pm

Pastry wrote: Wed Jul 19, 2017 11:11 pm
sunnydays wrote: Wed Jul 19, 2017 10:58 pm
Pastry wrote: Wed Jul 19, 2017 9:21 pm

Well if I ever decide to ditch my fun weekend car that drives as great as it breeding and take up drag racing instead, I know where to look :poke: :D
Funny how handling always comes up yet the 35is beats the M in almost all track tests :wink:
Heard it all before :roll: I've had both, so I know how they drive :poke:
I have been lucky enough to own both to own both an E86 & E89 and I would agree with Mr(?)Pastry , as such the E89 isnt a bad car but on the occasions I drove it like I stole it felt like it was at its limits whereas the E86 didnt
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Why does the 35is speedo stop at 160mph?

Post by john-e89 » Fri Jul 21, 2017 2:04 pm

Power is nothing without control. Same corner, same speed, im more concerned about the 35is breaking loose than the M. Both on all but new MPSS's. Not that I drive like a loon, but there's a couple tight corners that are off camber, the M is tighter. I would suggest that a 35is is quicker round a track due to the DCT, you simply cannot change gear as quickly with a manual box, plus there's no throttle lift with the DCT, that and the 35is has more torque.

Both splendid machines though. :)
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GuidoK
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Why does the 35is speedo stop at 160mph?

Post by GuidoK » Fri Jul 21, 2017 2:19 pm

buzyg wrote: Wed Jul 19, 2017 6:19 pm E85 CD .35, frontal area 1.91 m2, 338bhp @ 7900rpm (Precisely the RPM needed for the E85 to reach it's top speed in 5th gear). :thumbsup:
E89 CD .34, frontal area 1.96 m2, 335bhp @ 5900rpm ( Alas I don't know the power curve or max speed in gears/ratio's)
Afaik the z4m has a CD 0,38 and A is 1,92m²
(the front bumper of the z4m certainly isnt designed for top speed with its large vent holes)
So drag for the z4m is 0,7296q and the drag for the e89 is 0,6664q, so considerably lower. (the normal e85 is quite on par it seems with 0,6685, although somehow I still have a hard time believing it because the e89 has a coupe like roof and the e85 roof shape doesnt seem that aerodynamically....)
But I havent checked the e89 figures, and of course that also comes with different bumpers, so differend coefficients..
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Why does the 35is speedo stop at 160mph?

Post by buzyg » Fri Jul 21, 2017 5:42 pm

GuidoK wrote: Fri Jul 21, 2017 2:19 pm
buzyg wrote: Wed Jul 19, 2017 6:19 pm E85 CD .35, frontal area 1.91 m2, 338bhp @ 7900rpm (Precisely the RPM needed for the E85 to reach it's top speed in 5th gear). :thumbsup:
E89 CD .34, frontal area 1.96 m2, 335bhp @ 5900rpm ( Alas I don't know the power curve or max speed in gears/ratio's)
Afaik the z4m has a CD 0,38 and A is 1,92m²
(the front bumper of the z4m certainly isnt designed for top speed with its large vent holes)
So drag for the z4m is 0,7296q and the drag for the e89 is 0,6664q, so considerably lower. (the normal e85 is quite on par it seems with 0,6685, although somehow I still have a hard time believing it because the e89 has a coupe like roof and the e85 roof shape doesnt seem that aerodynamically....)
But I havent checked the e89 figures, and of course that also comes with different bumpers, so differend coefficients..
Good point I meant E86 CD is 0.35, from the BMW brochure :D :thumbsup:
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Why does the 35is speedo stop at 160mph?

Post by sunnydays » Sat Jul 22, 2017 11:36 am

So now that we have established the car is capable in the region of 173 - 177mph.

It seems simply because its not an 'M' they capped the speedo to 160 which is ridiculous....

Pbondar

Why does the 35is speedo stop at 160mph?

Post by Pbondar » Sat Jul 22, 2017 11:55 am

One could argue from a human factors viewpoint..

Normally they are limited to 155 anyway
Better to 'see' the limiter coming in at the 'top of the dial'
If you have a dial that goes to say 200mph then you will be upset when it 'only' does 165 or whatever..

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Why does the 35is speedo stop at 160mph?

Post by buzyg » Sat Jul 22, 2017 12:38 pm

sunnydays wrote: Sat Jul 22, 2017 11:36 am So now that we have established the car is capable in the region of 173 - 177mph.

It seems simply because its not an 'M' they capped the speedo to 160 which is ridiculous....
It's simply as it should be. :poke: :wink: :lol:
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