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Old 10-18-2017, 07:03 PM   #104
anassa
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I actually did take some time to google and find out why the distance from hub to clamp point would make a difference but as you mentioned yourself:

Quote:
Originally Posted by AFDanHef View Post
It was surprisingly hard to find something that explained this well actually. I wanted to find a nice handy dandy YouTube video but couldn't find sh1t.
It still doesn't make 100% sense why having the clamp point being farther away from hub = better stopping power. I understand it for cooling purposes or if for some reason the pad does not have full contact = more surface area to apply clamping force on, but if in both cases clamping force of the pad has full surface area contact -( being a casual enthusiast and not engineer )- I can't picture in my mind how it would help.

As for the initial example stopping the rotor = stopping the car, so that doesn't seem to make much difference, and when pushing the wheel of the car, we push the outside because we have best grip - like on a bicycle the bigger the gear the more torque you need to apply to push it forward, so the bigger the wheel the more torque you need, so if the wheel was huge - well I wouldn't even be able to push it then lol - but I would pull/push from where I have the best grip and maybe push from closer in if there was a handle. But this goes into a whole different talking because now we are practically talking about gearing and transmission.

Quote:
Originally Posted by AFDanHef View Post
1. Increase disc radius
Larger discs will allow for more brake torque as the brake pad will apply pressure at a larger radius, allowing for a higher moment. Brake torque is equal to the force applied by the pad multiplied by the distance at which the force is applied from the center of the wheel. In this case, we’re increasing the distance from the centre. This is a good thing.

https://www.carthrottle.com/post/eng...g-performance/
I can't imagine this in a way that makes sense.

Honestly this was more for me about the discussion and exploration of the idea then necessarily getting the perfectly correct answer.

Quote:
Originally Posted by AFDanHef View Post
Also, the 128i uses 300x24 in front and 300x20 in rear. 4mm thickness difference ... and probably pads and calipers are smaller. They would never use the exact same setup in the front as they would in the rear ... unless they were using some electric wizardry to control the bias ... and then what would be the point!?
I was just talking about diameter! Both being 300mm - the above examples of the m3 and 330ci also have different thickness, that is just one more factor that makes it more complicated, but again I think it has more to do with dispersion of the heat as heat is always the main enemy. Also it decreases the chance of cracking rotors.

As for what you mentioned about using the same setup front and rear, that was only talking about rotor diameter the calipers clamping down on the 300mm rotors would be different, like the e36 m3 front and rear caliper/piston size are different - thus still having acceptable/safe brake bias.

So that brings me still to the idea of using:

Rotors:
-Front: e46 300x22
-Rear: 128i 300x20
Calipers:
-Front: e36 m3
-Rear: e36 m3
Brake Booster: e36 m3 booster?

The rear would get sufficient cooling - the difference in front/rear piston/caliper size will keep the brake bias even, e36 m3 booster would give solid pedal feel. The front might get hot/fade quickly if on track without good ducting and cooling since it is a smaller rotor (just guesstimating)- but will be fine on the street, could potentially be not as good as stock e36 m3 brake setup due to above mentioned theory, but still better than stock caliper, and potentially best 15" wheel setup?? Provided the caliper itself isn't too big.

Biggest problem is . . . will the caliper fit on a e46/z3 bracket for 300mm discs??



(Btw thanks for diving into this with me, this is more fun mind exercise for me than anything else )
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Last edited by anassa; 10-18-2017 at 07:07 PM. Reason: grammar/spelling
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