# E46 M3 torsional rigidity...



## ALEX325i (Dec 19, 2001)

Does anybody know what the E46 M3 torsional rigidity is? :dunno:


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## nate (Dec 24, 2001)

Same as the E46 coupe before the strut brace :dunno:


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## ALEX325i (Dec 19, 2001)

Thanks! :thumb:

I though so too. However, since the E46 Coupe and the E46 M3 do not share a single body panel, I thought that maybe the torsional rigidity had been revisited too... :dunno:


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## nate (Dec 24, 2001)

ALEX325i said:


> *Thanks! :thumb:
> 
> I though so too. However, since the E46 Coupe and the E46 M3 do not share a single body panel, I thought that maybe the numbers were different... :dunno: *


I don't think that there is any additional bracing :dunno:

Still selling your M3?


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## ALEX325i (Dec 19, 2001)

nate328Ci said:


> *
> 
> I don't think that there is any additional bracing :dunno:
> 
> Still selling your M3? *


Technically yes...  I started to get leads on the 325i though... Funny how I just can't reach those who left me messages inquiring about the M3...


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## nate (Dec 24, 2001)

ALEX325i said:


> *
> 
> Technically yes...  I started to get leads on the 325i though... Funny how I just can't reach those who left me messages inquiring about the M3...   *


You can drive the M3 everyday! :thumb:


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## ALEX325i (Dec 19, 2001)

nate328Ci said:


> *
> 
> You can drive the M3 everyday! :thumb: *


I sure can! :thumb:


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## Dr. Phil (Dec 19, 2001)

ALEX325i said:


> *Funny how I just can't reach those who left me messages inquiring about the M3...   *


:lmao:

And I now you try back at 7 or 8 times :lmao:


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## ALEX325i (Dec 19, 2001)

PM 325xiT said:


> *
> :lmao:
> 
> And I now you try back at 7 or 8 times :lmao:  *


Most definitely :angel:


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## ezsce46 (Mar 7, 2002)

ALEX325i said:


> *Does anybody know what the E46 M3 torsional rigidity is? :dunno: *


I think since E46 M3 uses E46 convertible's subframe, it should be more rigid than the regular E46 coupe.


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## in_d_haus (Jan 2, 2002)

I was told recently that it is 11,000lbs to twist and E46 (non-M) this is up from the E36 which was something like 8000lbs.


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## nate (Dec 24, 2001)

in_d_haus said:


> *I was told recently that it is 11,000lbs to twist and E46 (non-M) this is up from the E36 which was something like 8000lbs. *


E46

Sedan (w/o folding seats): 18000Nm/deg of torsion 
Sedan (w/folding seats): 13000Nm 
Sport wagon (w/folding seats): 14000Nm 
Coupe (w/folding seats): 12500Nm 
Convertible: 10500Nm

The M3 is stiffer due to the subframe....


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## in_d_haus (Jan 2, 2002)

I got my info from the Mini dealer who was bragging because the new Mini is stiffer than the 3er BMW. They said it takes 22,000lbs to twist a Mini


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## EdCT (Mar 14, 2002)

It's interesting to me that whenever a carmaker comes up with a new model, they always manage to find another 10-50 percent addition rigidity.

Where do they find it?

Why can't they just make it as solid as it needs to be the first time?

Where's the limit?

Ed


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## bmw325 (Dec 19, 2001)

Ed--

I've noticed that too. I think this has become very prevalent in recent years due to advances in Computer Aided design software used to design the bodyshells and maybe increased used of high strenght steel. I think those "increase" numbers are starting to taper off again-- for example, I think the E65 7 series is only about 10% more rigid than the e38. But basically the answer to your question is that the body shell designers make the car as rigid as they can given the technology, time and budget they have at the time they design the car. Obviously, these factors change with each new designs. I also read somewhere that rigidty has only recently become such a big topic for carmakers-- probably due to higher saftey requirements, and the desire to improve the suspension performance/comfort. So, in the past 5 years, they've focused a lot of energy on it. Initially, it was easy to make big gains over previous designs-- but I'd bet they're reaching a plateau now without going to new materials like carbon fiber.

The other interesting this about this whole rigidity topic is that you never see the actual figures published (yes, people on this board have managed to dig them up for the e46)-- or comparisons between cars. I think someone posted that you can't really compare these numbers between car makers because they all use different techniques to make these measurements-- and some measure the bodyshell w/ glass installed-- others do it without, etc. Despite this, i've tried digging up the numbers for other cars, but haven't found anything.


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## Sean (Dec 22, 2001)

Wait a minute. Alex, I thought you had sold the M3? :dunno:


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## AF (Dec 21, 2001)

Sean said:


> *Wait a minute. Alex, I thought you had sold the M3? :dunno: *


I am pretty sure he did sell it but this post is from May !!


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## EdCT (Mar 14, 2002)

robg said:


> *Ed--
> 
> I've noticed that too. I think this has become very prevalent in recent years due to advances in Computer Aided design software used to design the bodyshells and maybe increased used of high strenght steel. I think those "increase" numbers are starting to taper off again-- for example, I think the E65 7 series is only about 10% more rigid than the e38. But basically the answer to your question is that the body shell designers make the car as rigid as they can given the technology, time and budget they have at the time they design the car. Obviously, these factors change with each new designs. I also read somewhere that rigidty has only recently become such a big topic for carmakers-- probably due to higher saftey requirements, and the desire to improve the suspension performance/comfort. So, in the past 5 years, they've focused a lot of energy on it. Initially, it was easy to make big gains over previous designs-- but I'd bet they're reaching a plateau now without going to new materials like carbon fiber.
> 
> The other interesting this about this whole rigidity topic is that you never see the actual figures published (yes, people on this board have managed to dig them up for the e46)-- or comparisons between cars. I think someone posted that you can't really compare these numbers between car makers because they all use different techniques to make these measurements-- and some measure the bodyshell w/ glass installed-- others do it without, etc. Despite this, i've tried digging up the numbers for other cars, but haven't found anything. *


Rob,

Good answer, makes sense.

Ed


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