320i brakes in front and now..., The rears feel undersized Options

[banderson]

I did the standard conversion to 320i front calipers and removed the proportioning valve last summer and now I think that I may have increased the stopping distance. The rears don’t feel like they are working hard enough. I overhauled the system with new rotors, rear caliper rebuild kits, DOT SS lines and street pads.

Because my front brake pistons are bigger, it takes less effort to lock the front wheels than it did before. Now the front wheels lock well before the rears come close.

I havn’t heard of anyone complaining about this before and Grassroots motorsports reported that they needed an adjustable valve to keep there rears from locking. This makes me wonder if my rears are working properly. They get hot, so I know they are doing something. The pedal is solid and they don’t bind.

I am considering changing to a high performance street pad, or putting different ones on the back, but I don’t want them to grab too much.

Your thoughts?

[Brad Roberts]

I need to get a engineer to do thermal tests on a 914 rotor with stock calipers/pads and with the BMW setup on a stock rotor. Heat is the killer here and I personally believe the BMW caliper is too much for the stock rotor to handle proper heat dissipation. It may stop 2-3 times real nice with tires smoking... but how many times can you do this before the brakes fade from boiled brake fluid ?? I know how many times and how fast the stock ones fade. I'm willing to bet the BMW setup fades twice as fast.


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