M5 Big Brake Kit
06-01-2008, 01:50 AM
#21
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Originally Posted by nicke60gre' post='592789' date='Jun 1 2008, 11:29 AM
Yes they are amazing, I have now only the front ones installed and the stopping ability is incomparably better to the 545i (348mm) I had before.
Can't wait to put the rear 370mm on and make some braking tests with my 1,560kg light-weight car, almost 300kg. (660 lb) lighter than 545i/550i/M5 
Wtf are you talking about ?
545i 1630 Kg, 645ci 1615 Kg, M5 1750 kg (empty cars)
Edit : 1460 Kg the 520i, so 150 Kg less, not 300 .
PS :
The weight can help the car to stop : the Continental GT brakes very well, with its 2500 kg .
06-01-2008, 01:52 AM
#22
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Originally Posted by andy545' post='592791' date='Jun 1 2008, 11:36 AM
Nick, get some stronger seat belts for the braking test 
Don't worry, we have the engine in the front and M5 brakes are not so powerful : it doesn't become a Porsche GT3 RS (that is absolutely astonishing in braking on track! - without 4 points belt you would jump against the windshield) .
06-01-2008, 02:05 AM
#23
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Originally Posted by AlexFW' post='592793' date='Jun 1 2008, 12:50 PM
The diffence is not given by the mm but by the pistons of the calipers .
Wtf are you talking about ?
545i 1630 Kg, 645ci 1615 Kg, M5 1750 kg (empty cars)
Edit : 1460 Kg the 520i, so 150 Kg less, not 300 .
PS :
The weight can help the car to stop : the Continental GT brakes very well, with its 2500 kg .
Wtf are you talking about ?
545i 1630 Kg, 645ci 1615 Kg, M5 1750 kg (empty cars)
Edit : 1460 Kg the 520i, so 150 Kg less, not 300 .
PS :
The weight can help the car to stop : the Continental GT brakes very well, with its 2500 kg .
Source: BMW
M5 (4012 lbs)
550i (3968 lbs)
Divide by 2.2
06-01-2008, 03:57 AM
#24
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Damm Nick 
I need those BMW Performance stickers for my 545 calipers.
I need those BMW Performance stickers for my 545 calipers.
06-01-2008, 06:11 AM
#25
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Originally Posted by nicke60gre' post='592797' date='Jun 1 2008, 12:05 PM
So heavier means better? Wtf they do in F1 then? Are they crazy using carbon parts and make cars lighter?
545i :
1630 Kg
550i :
http://snipurl.com/2bw01
1660Kg
M5 :
http://snipurl.com/2bw04
1755Kg
These are numbers we have here on logbook (and I think also in other European countries)
550i is 100kg lighter .
Don't force me to search for N62N and S85 weights ...
06-01-2008, 06:39 AM
#26
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Originally Posted by AlexFW' post='592793' date='Jun 1 2008, 04:50 AM
PS :
The weight can help the car to stop : the Continental GT brakes very well, with its 2500 kg .
The weight can help the car to stop : the Continental GT brakes very well, with its 2500 kg .
did you forget your basic physics lesson about momentum and what it takes to overcome it? the GT has some HUGE multi piston brakes. If weight dictated braking power, SUVs would stop on a dime!
Force=Mass*Acceleration
braking is negative acceleration (deceleration). so, if you increase mass, the force applied MUST be higher to maintain the same desired deceleration rate. (The brakes apply the force.)
so,
if we solve the equation for acceleration, you get
accel=force/mass
Let's say you want two cars of different weight to have the same braking (remember, negative acceleration) rate.
(force1/mass1) = (force2/mass2)
if you increase mass, you are increasing the denominator. Thus, the total fraction is smaller unless you increase the force as well. translation=bigger mass needs bigger brakes to slow down at the same rate.
the additional rolling friction due to added weight does not help in any significant amount when you want to stop QUICKLY. Sure, the GT will take less distance to coast to a stop (given the aerodynamic drag coefficient is the same) but if you need to stop before you hit that wall in front of you it's not much help.
class dismissed.
06-01-2008, 07:19 AM
#27
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Originally Posted by fvicente' post='592835' date='Jun 1 2008, 10:39 PM
did you forget your basic physics lesson about momentum and what it takes to overcome it? the GT has some HUGE multi piston brakes. If weight dictated braking power, SUVs would stop on a dime!
Force=Mass*Acceleration
braking is negative acceleration (deceleration). so, if you increase mass, the force applied MUST be higher to maintain the same desired deceleration rate. (The brakes apply the force.)
so,
if we solve the equation for acceleration, you get
accel=force/mass
Let's say you want two cars of different weight to have the same braking (remember, negative acceleration) rate.
(force1/mass1) = (force2/mass2)
if you increase mass, you are increasing the denominator. Thus, the total fraction is smaller unless you increase the force as well. translation=bigger mass needs bigger brakes to slow down at the same rate.
the additional rolling friction due to added weight does not help in any significant amount when you want to stop QUICKLY. Sure, the GT will take less distance to coast to a stop (given the aerodynamic drag coefficient is the same) but if you need to stop before you hit that wall in front of you it's not much help.
class dismissed.
Off to the mall 
, seriously +1
06-01-2008, 07:38 AM
#28
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Originally Posted by fvicente' post='592835' date='Jun 1 2008, 04:39 PM
did you forget your basic physics lesson about momentum and what it takes to overcome it? the GT has some HUGE multi piston brakes. If weight dictated braking power, SUVs would stop on a dime!
It was an example, just to talk ... I know 2 people who drove the ContinentalGT and they reported "It's heavy, but very good brakes!"
06-01-2008, 08:54 AM
#29
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My Ride: 2007 E60 530i
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STEP | Sport | Premium | NAV | Logic 7
EXTERIOR:
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There Alex goes again with his hearsay.
06-01-2008, 09:04 AM
#30
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Originally Posted by AlexFW' post='592794' date='Jun 1 2008, 11:52 AM
Don't worry, we have the engine in the front and M5 brakes are not so powerful : it doesn't become a Porsche GT3 RS (that is absolutely astonishing in braking on track! - without 4 points belt you would jump against the windshield) .
I was just just having some fun mate, relax.