BimmerFest BMW Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
2,487 Posts
Discussion Starter · #3 ·
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:
 

·
I like cookies.
Joined
·
18,102 Posts
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?
 

·
Registered
Joined
·
2,487 Posts
Discussion Starter · #5 ·
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... :rolleyes: :D
 

·
The Original Dr. Phil
Joined
·
10,985 Posts
ALEX325i said:
Funny how I just can't reach those who left me messages inquiring about the M3... :rolleyes: :D
:lmao:

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

·
I like cookies.
Joined
·
18,102 Posts
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....
 

·
zeddy
Joined
·
7,668 Posts
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
 

·
Registered
Joined
·
10,697 Posts
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.
 

·
zeddy
Joined
·
7,668 Posts
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
 
1 - 18 of 18 Posts
Top