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      06-05-2012, 06:48 PM   #9
Naturally agitated
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Drives: 11 E90 M3, 15 WRX STi, 04 M3
Join Date: May 2012
Location: NoVa

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Originally Posted by r53s65e90 View Post
Can I check out any FMSI if I know the pagid reference number there?

Edit: I just looked, that gives the overall height of the backing plate, not necessarily the pad width. Getting real dimensions from FMSI specs seems like pulling teeth to me. It has taken a lot of first-hand intelligence to get specs from various pads to ensure that the swept area matches the rotor diameter - annulus when matching different caliper to rotor combinations. It also is a fundamental requirement when calculating the brake torque. The length of the pad is irrelevant, but the width is very much relevant and can change the bias significantly.

Your calculations are more accurate. I just used rotor diameter instead of the more accurate rotor diameter minus 60mm which takes into account where the piston applies force. If you do this you get 60*60*300/(46*46*290)=1.76. I was just interested in ballpark numbers to start with. Once I have the real piston sizes I can go fancy.
Gotcha - I always attach units to calculations so I don't lose track of where I got them from, which is confusing enough as it is.

This sounds nice. Can you share?
PM your eMail address.. I'll remove the riff-raff and shoot it over. It's rather comprehensive.. .. and not finished, but should still be an interesting read and help you with any calculations you're making. I'll promise you that, at least for the E46 M3, it'll be more comprehensive than anything else online!