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      12-29-2012, 12:56 PM   #4
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bigjae1976's Avatar

Drives: 11 E90 M3 Individual
Join Date: Mar 2006
Location: Wichita, KS

iTrader: (14)

Garage List
2004 BMW M3  [4.50]
2011 BMW E90 M3  [5.00]
2013 BMW 328i  [5.00]
I may test these at Circuit of the Americas in a couple of weeks and I was thinking about how to set up a test to collect useful data.

I think COTA will be the perfect place to test these. There's a 3/4 mile long straight that unlike most that utilize NASCAR ovals, the overall elevation change is neglible. At Texas World Speedway, you have to climb up the banking a little due to the trajectory of the fastest line exiting the turns leading onto that front straight. Back to COTA, 3/4 mile straight that starts down hill, climbs up, back down a bit into a flat braking zone into a sharp left hander. On Vettel's pole lap, he went from 308 kph to about 86 kph. For us americans, Vettel was scrubbing off 140mph which according to the commentators is -6g's of force! I will not be going anywhere near those speeds but I would hazard a very rough guess that I'll be going from 140mph to about 40 mph.

How about this...I know I'll get at least 4 sessions on the full course. So I run 2 with the Pagid Yellows and then 2 with the ST Racing pads. I'll try to pick something comparable (less initial bite, longer life).

I'll be in my E90 M3 with NT01s. The only adjustment other than the pads is tire pressure after each is 38psi hot. I'll swap and measure the pads after 2 sessions. I'll use a micrometer which reads 100th of mm (Nanometer???...not sure what that is since I'm a filthy Imperialist American).

I'll collect the following data points:

# hot laps (subtract warm up and cool down)
before thickness of pads
after thickness of pads from 2 sessions

Divide the # laps into the change in pad thickness to get a wear rate of per lap. Of course, add in the subjective measurements of fade resistance, pedal modulation (on/off or a progressive feel), stopping power.

2015 F34 328iX GT Glacier Silver
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red