BMW M5 Forum and M6 Forums banner

1 - 20 of 72 Posts

·
Registered
Joined
·
675 Posts
Discussion Starter #1
M6 & M5 atthe nurburgring

apparently the m6 is 8 seconds quicker round the circuit,now considernig that its slightly lighter and has the same engine,is this possible ? Engineers reckon the shorter wheelbase allows it to be more agile.
 

·
Registered
Joined
·
2,810 Posts
Re: M6 & M5 atthe nurburgring

its not really THAT much smaller.. and overall lenth is really close.

I think in a coupe version they can go a bit more extreme on the handling, giving up a bit more comfort. Possibly a lower center of gravity due to the CF roof. Isn't the overall weight a bit lower too?

Alot of other things could account as well. Coldest part of winter increasing power output from the engine. Driver more familar with the 6. Some additional tuning of SMG, etc.

We really need back to back same day tests to judge.
 

·
Registered
Joined
·
344 Posts
Re: M6 & M5 atthe nurburgring

vndkshn said:
its not really THAT much smaller.. and overall lenth is really close.

I think in a coupe version they can go a bit more extreme on the handling, giving up a bit more comfort. Possibly a lower center of gravity due to the CF roof. Isn't the overall weight a bit lower too?

Alot of other things could account as well. Coldest part of winter increasing power output from the engine. Driver more familar with the 6. Some additional tuning of SMG, etc.

We really need back to back same day tests to judge.
I thought M6 is 200 to 300lb lighter than M5.
 

·
Registered
Joined
·
2,810 Posts
Re: M6 & M5 atthe nurburgring

sounds about right. that could make up a sizable difference by itself. Can't remember the rule of thumb, something 10lbs is worth 1hp or something like that. Of course, I am thinking in terms of drag racing.
 

·
Registered
Joined
·
344 Posts
Re: M6 & M5 atthe nurburgring

vndkshn said:
sounds about right. that could make up a sizable difference by itself. Can't remember the rule of thumb, something 10lbs is worth 1hp or something like that. Of course, I am thinking in terms of drag racing.
I just double checked my number, maybe I am way to optimistic. According to BMW, M5 is 3.6kg/bhp while M6 is at 3.5kg/bhp, both of them have the 507bhp V10 engine, so that gives you 1825.2kg and 1774.5kg respectively (of course lots error due to rounding there, since there are only two significant figure in the kg/bhp number). That's only a difference of 50.7 kg which is roughly 112 lb. That's something but not as much as I said earlier. I guess the suspension setting might be a lot different on M6 than the one on M5.
 

·
Registered
Joined
·
1,655 Posts
Re: M6 & M5 atthe nurburgring

... and i think as the ring is so long it is not a good indication of car's performance. you can never repeat the same conditions to be able to compare apples to apples, and with the lenght of the curcuit, differences accumulate to the point of skewed and non-representative results...

i am not defending bmw, just stating something that i have been thinking for a while...

alex
few cars

ps... anybody that has ridden a sports bike actually has encountered that i am sure- one moment you have maximum traction and you are scraping knees left and right, the next moment you enter a colder area (feels like entering suddenly a freezer) and traction is reduced immensly.... i am sure the ring has tons of transitions like that and passes done on different days present vastly different conditions.... so too many variables are presented that a car being 10 seconds faster than another one is not a significant difference. imo.
 

·
Registered
Joined
·
200 Posts
Re: M6 & M5 atthe nurburgring

Mhhh. Would like to see engines in the two cars on the dyno (or something else that gives an indication of the produced power. I wouldn't be surprised if some difference showed up...

Guust
 

·
Administrator
Joined
·
8,806 Posts
Re: M6 & M5 atthe nurburgring

AJ said:
ps... anybody that has ridden a sports bike actually has encountered that i am sure- one moment you have maximum traction and you are scraping knees left and right, the next moment you enter a colder area (feels like entering suddenly a freezer) and traction is reduced immensly.... i am sure the ring has tons of transitions like that and passes done on different days present vastly different conditions.... so too many variables are presented that a car being 10 seconds faster than another one is not a significant difference. imo.
You assume correctly - the Ring is so long that I have encountered snow at one part of the lap and clear blue skies at the other end.
 

·
Registered
Joined
·
3,886 Posts
Re: M6 & M5 atthe nurburgring

Guust Flater said:
Mhhh. Would like to see engines in the two cars on the dyno (or something else that gives an indication of the produced power. I wouldn't be surprised if some difference showed up...

Guust
I don't think there is any chance the M6 has a more highly 'tuned' version of the V10. If it did, BMW would be the first to tout the extra hp as justification for the exhorbitant $'s they are charging. An 11 lb weight savings on a carbon roof might give you a few tenths, but won't make as much difference as a 30 lb difference in drivers.

I suspect the major difference is suspension settings, combined with a slightly lower cg, and very slightly lower weight. The weight will make some small difference in acelleration, but will probably have more effect on the ability to transition in curves. Overall, cg, weight, and suspension settings probably are enough for the difference.

And of course, whatever the weather and track conditions are on that specific day will influence times significantly as well.
 

·
Registered
Joined
·
1,655 Posts
Re: M6 & M5 atthe nurburgring

Wolverine said:
An 11 lb weight savings on a carbon roof might give you a few tenths, but won't make as much difference as a 30 lb difference in drivers.
not to dig in, but 11 pounds difference will give you exactly nothing in terms of accelleration in the real world.

the m6 prolly transitions faster due to lower center of gravity... but who knows... nobody has driven them to tell us... yet :wroom: :haha:

alex
few cars
 

·
Registered
Joined
·
816 Posts
Re: M6 & M5 atthe nurburgring

vndkshn said:
We really need back to back same day tests to judge.
That was my question. Is the 8 secs difference based on a same day test, by the same driver, or at least 2 drivers of similar apptitude?

About the carbon fibre roof: the press release reads " ... haved saved more than 4.5 kilos on the M6"

About M6's weight: "dry weight is limited to a mere 1,785 kilos or 3,936 lb (ECE)"

About kg:bhp: M5 @ 3.5kg:bhp. M6 @ 3.3kg:bhp. (BMW press release source).

At least in theory, we would expect the M6 to out run the M5 in the ring, if both exposed to identical environment and driver.
 

·
Moderator Emeritus
Joined
·
2,823 Posts
Before we adopt this alleged 8-second differential as gospel, shouldn't we at least know the source so we can determine if other details are available? Perhaps markf can tell us where his information came from.
 

·
Registered
Joined
·
955 Posts
i wonder who did the test?

could it be Sport Auto? becasue i recall they tested the M5 on Nurburgring in less than ideal condition.

and i wonder if the M6 has the speed limiter removed.

at this point, the information we have is simply not enough to form any valid conclusion.
 

·
Registered
Joined
·
1,479 Posts
Re: M6 & M5 atthe nurburgring

AJ said:
not to dig in, but 11 pounds difference will give you exactly nothing in terms of accelleration in the real world.

the m6 prolly transitions faster due to lower center of gravity... but who knows... nobody has driven them to tell us... yet :wroom: :haha:

alex
few cars
The 11 lbs is just the saving in the CF Roof the overall weight difference is about 112lbs
 

·
Registered
Joined
·
2,810 Posts
My guess (assuming "legit" source, same driver, etc)... weather conditions... a bright sunny cold day. Bright and sunny to warm the track a bit.. cold for more dense air which can help the engine provide a bit more power. Also, more aggressive suspension tuning.

Possibly some additional computer/SMG tuning.

Then again, maybe the M5 had a full tank the the M6 a half tank.
 

·
Registered
Joined
·
3,886 Posts
Re: M6 & M5 atthe nurburgring

AJ said:
not to dig in, but 11 pounds difference will give you exactly nothing in terms of accelleration in the real world.

the m6 prolly transitions faster due to lower center of gravity... but who knows... nobody has driven them to tell us... yet :wroom: :haha:

alex
few cars
"a few tenths" refers to the 'ring time, not an acelleration run.
 

·
Registered
Joined
·
704 Posts
The weight diffrence along can account for most of that diffrence. Most people forget while weight and power determine acceleration that weight has even more of an effect on the cornering speeds. The two cars ride on the same size tires and tire grip progresses sub-linearly with force applied so the M6 can corner faster than the M5 even before you factor in the lower CG. So it can corner faster, exit the turns with more speed and then out accelerate the M5 from there.

Weight matters more than most think, this is why I was so against the heavier "torque engine" during the debates :)
 

·
Registered
Joined
·
28 Posts
Re: M6 & M5 atthe nurburgring

clee19821013 said:
I thought M6 is 200 to 300lb lighter than M5.
Acoording to the latest issue of Bimmer magazine(featuring M6 on cover) they list the M5 at 4026lbs and the M6 at 3762lbs, a diiference of 264lbs.

On a sidebar (do not mean to hijack the thread), has the January 2005 issue of UK CAR Magazine hit the states yet for non subscribers? Been looking for it at my local Barnes & Borders. Want to read the comparison test between the M5 vs CLS 55 and the M5 vs 911. It sures seem very late to not have arrived yet.

Thanks
 
1 - 20 of 72 Posts
Top