Brake Caliper problem

[Yunlong Xu]

Hi guys, I've got a quesiton about brake calipers that I hope someone can help me with.

As you know, for most of calipers, there is a maximum operating line pressure. eg 70bar for Brembo P32G.

I'm just wondering what happens if the pressure from the master cylinder exceeds this limit? Does the pressure saturates at the limit or does it keep going up(but adds the risk of caliper failure)?

cheers

[Yunlong Xu]

Hi guys, I've got a quesiton about brake calipers that I hope someone can help me with.

As you know, for most of calipers, there is a maximum operating line pressure. eg 70bar for Brembo P32G.

I'm just wondering what happens if the pressure from the master cylinder exceeds this limit? Does the pressure saturates at the limit or does it keep going up(but adds the risk of caliper failure)?

cheers

[TacoPete]

I would think that you would blow apart the seals first before the caliper exploded. You also might want to look into what your line ratings are. The safest bet would be to call your caliper company and ask.

[STRETCH]

You'll actually find the caliper will fail before its seals, but only if its rated lower than the brake lines and master cylinder etc... strange thing to wonder - your not planning on runnning above the operating limit are you?

[Yunlong Xu]

No, not really planning to run over the limit. But just wondering what happens if the driver suddenly has an adrenalin rush...

[Drew Price]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Yunlong Xu:
No, not really planning to run over the limit. But just wondering what happens if the driver suddenly has an adrenalin rush... </div></BLOCKQUOTE>


http://fsae.com/groupee_common/emoticons/icon_biggrin.gif System should be designed so that you have enough safety margin that when you driver has a frighten, he doesn't pop the calipers.


Best,
Drew

[Yunlong Xu]

But I'm just thinking the higher the pressure you can run at, the smaller the discs are and you save weight(of course, assuming other properties are not affected, and heat dissipation is still not a problem,etc)

Say the 'adrenalin rush' results in 50% more force on the brake pedal. Then it means if I really want to play safe then I'd design for a normal operating pressure of about 1/1.5 of the rated maximum of the caliper. And hence 1.5 larger diameter for the discs comparing with the ones I would use if I designed it with the rated maximum pressure of the caliper.

Of course I'm not saying that designing the brakes operating at the rated maximum pressure is a good thing to do(it's actually stupid). But I'm just wondering how close you can get to it or how large a margin you should leave.

Bear in mind that the manufacturer should have alreayd included the safety factor into their specification(ie, if it says 70bar, but they've used a safety factor of two, you probably won't pop the caliper till 140bar)

And racing is always about pushing to the limit while still having a good probability of being safe.