Question about SMG tranny

Last E92 M3 · 11-09-2006, 07:59 PM

i heard Z4 M coupe perform really well.
btw, i dont like convertibles...
i havent seen it in person but next week, i am going back to home.
i will go to bmw dealer and see what's there.

JK42 · 11-09-2006, 08:13 PM

The Z4 M Coupé is not a Convertible - it's a Coupé - as the name implies - and probably the most fun BMW that there is right now. The Z4 M Roadster is the convertible version, and I'd skip that one, the chassis is not even nearly as rigid on the convertible, not as fun to drive. I don't like convertibles that much either, even if the weather might be good. They're noisy and you just get bored of the sunshine. I like my A/C even in hot climates.

Best regards,

Jussi

Last E92 M3 · 11-09-2006, 08:32 PM

i am just saying it in general, i know what coupe is...though i ask "stupid" questions on this forum regarding bmw

(i am not that stupid!)
i am with you. i'd take a/c even if it consumes more gas.
convertibles mess up my hair :/ lol! i am playing guys...hahaha..

replicat · 11-09-2006, 10:09 PM

Question: I thought that in anticipation of the chassis flexing in the Roadster with out a roof or B and C pillars, M division stiffened the Z4 M Roadster's chassis alot, so much that it even surpassed the Coupe in a rigidity test. Just info I thought I remembered hearing on SPEED TV test drive of the M models.

-Pete.

JK42 · 11-10-2006, 11:54 AM

Not correct.

The Z4 M Roadster chassis has about 14500Nm of torsional rigidity, which is indeed very much better than the old Z3 M Roadster which was about as stiff as a Bratwurst

- But as a result, the hardtop version, i.e. the Z4 M Coupé has the most rigid chassis of all current BMW models - with torsional rigidity of 32000Nm. The 130i comes as a good second with around 25000Nm.

Best regards,

Jussi

replicat · 11-10-2006, 05:38 PM

Oh hokie dokie, I must have heard incorrectly, they probably were saying what you just did, about it being stiffer than the Z3 M Coupe.

swamp2 · 11-12-2006, 01:28 AM

Quote:

Originally Posted by JK42

Not correct.

The Z4 M Roadster chassis has about 16000Nm of torsional rigidity, which is indeed very much better than the old Z3 M Roadster which was about as stiff as a Bratwurst

- But as a result, the hardtop version, i.e. the Z4 M Coupé has the most rigid chassis of all current BMW models - with torsional rigidity of 32000Nm. The 130i comes as a good second with around 25000Nm.

Best regards,

Jussi

Z4 M is darn stiff, stiffer than even a Murcielago. Where did you find these torsional stiffness specs? It would be interesting to know the spec for all BMW models. BTW, the proper unit of torsional stiffness is Nm/degree (or ftlb/degree). Leaving off the per degree is like saying 50 km/hr = 50 km.

JK42 · 11-12-2006, 09:21 AM

Quote:

Originally Posted by swamp2

Z4 M is darn stiff, stiffer than even a Murcielago. Where did you find these torsional stiffness specs? It would be interesting to know the spec for all BMW models. BTW, the proper unit of torsional stiffness is Nm/degree (or ftlb/degree). Leaving off the per degree is like saying 50 km/hr = 50 km.

Yes, it's marked Nm/o (small o meaning degree.) I left that out for brevity since I wasn't going to dig up the source at that time.

The torsional stiffness was mentioned in the Official press release of the Z4 M models. Part of the one for the Z4 M Coupé can be found here:

http://www.carbodydesign.com/archive...z4-m-coupe.php

One for the Roadster can found at least here, and several other web pages:

http://www.worldcarfans.com/news.cfm...ml/country/gcf

It was lower than I remembered at 14500Nm/o instead of 16k.

Most other models can be asked from your local knowledgeable reseller or importer, but I haven't seen them on the web anywhere, which would be nice to see, as you mentioned. They should just include them on the specs on the bmw.com website.

Regards,

Jussi

replicat · 11-13-2006, 07:21 PM

Quote:

Originally Posted by JK42

Yes, it's marked Nm/o (small o meaning degree.) I left that out for brevity since I wasn't going to dig up the source at that time.

The torsional stiffness was mentioned in the Official press release of the Z4 M models. Part of the one for the Z4 M Coupé can be found here:

http://www.carbodydesign.com/archive...z4-m-coupe.php

One for the Roadster can found at least here, and several other web pages:

http://www.worldcarfans.com/news.cfm...ml/country/gcf

It was lower than I remembered at 14500Nm/o instead of 16k.

Most other models can be asked from your local knowledgeable reseller or importer, but I haven't seen them on the web anywhere, which would be nice to see, as you mentioned. They should just include them on the specs on the bmw.com website.

Regards,

Jussi

Good links above, Ive been on the sites for 20mins now :rocks:

11-09-2006, 07:59 PM	#23
Last E92 M3 Lieutenant Colonel 34 Rep 1,507 Posts Drives: BMW M3 Join Date: Nov 2006 Location: Virginia iTrader: (0)	i heard Z4 M coupe perform really well. btw, i dont like convertibles... i havent seen it in person but next week, i am going back to home. i will go to bmw dealer and see what's there.
	Appreciate 0 Quote

11-09-2006, 08:13 PM	#24
JK42 First Lieutenant 20 Rep 374 Posts Drives: E70 BMW X5 4.8i Join Date: Oct 2006 Location: Northern Europe iTrader: (0)	The Z4 M Coupé is not a Convertible - it's a Coupé - as the name implies - and probably the most fun BMW that there is right now. The Z4 M Roadster is the convertible version, and I'd skip that one, the chassis is not even nearly as rigid on the convertible, not as fun to drive. I don't like convertibles that much either, even if the weather might be good. They're noisy and you just get bored of the sunshine. I like my A/C even in hot climates. Best regards, Jussi
	Appreciate 0 Quote

11-09-2006, 08:32 PM	#25
Last E92 M3 Lieutenant Colonel 34 Rep 1,507 Posts Drives: BMW M3 Join Date: Nov 2006 Location: Virginia iTrader: (0)	i am just saying it in general, i know what coupe is...though i ask "stupid" questions on this forum regarding bmw (i am not that stupid!) i am with you. i'd take a/c even if it consumes more gas. convertibles mess up my hair :/ lol! i am playing guys...hahaha..
	Appreciate 0 Quote

11-09-2006, 10:09 PM	#26
replicat Lieutenant 23 Rep 515 Posts Drives: 40MPG Join Date: Oct 2006 Location: Southern California iTrader: (0)	Question: I thought that in anticipation of the chassis flexing in the Roadster with out a roof or B and C pillars, M division stiffened the Z4 M Roadster's chassis alot, so much that it even surpassed the Coupe in a rigidity test. Just info I thought I remembered hearing on SPEED TV test drive of the M models. -Pete.
	Appreciate 0 Quote

11-10-2006, 11:54 AM	#27
JK42 First Lieutenant 20 Rep 374 Posts Drives: E70 BMW X5 4.8i Join Date: Oct 2006 Location: Northern Europe iTrader: (0)	Not correct. The Z4 M Roadster chassis has about 14500Nm of torsional rigidity, which is indeed very much better than the old Z3 M Roadster which was about as stiff as a Bratwurst - But as a result, the hardtop version, i.e. the Z4 M Coupé has the most rigid chassis of all current BMW models - with torsional rigidity of 32000Nm. The 130i comes as a good second with around 25000Nm. Best regards, Jussi
	Appreciate 0 Quote

11-10-2006, 05:38 PM	#28
replicat Lieutenant 23 Rep 515 Posts Drives: 40MPG Join Date: Oct 2006 Location: Southern California iTrader: (0)	Oh hokie dokie, I must have heard incorrectly, they probably were saying what you just did, about it being stiffer than the Z3 M Coupe.
	Appreciate 0 Quote