Why BBK for front only

[yomny]

I had never seen this done much until now. It seems to be a common upgrade within our community. Why do some only upgrade their front brakes to Brembo, Stoptech, AP... and leave the rear setup stock? I would rather hear from people that have done so and their reasons why. I'm not a racing pro but with EBD(brake force thing) on modern cars wouldn't a strong bite upfront only cause the rear to act up? I also see that some front rotors are smaller than the rear, this is due because of the e-brake drum being within the disc?

[f0rge]

The same reason almost all cars come from the factory with larger vented rotors in the front and smaller solid ones in the back, the front brakes do approx 70% of the braking.

[choi0706]

smaller in diameter?

on some kits (not sure about frs/brz) you loose the parking brake going with bbk in the rear..

[CSG David]

Originally Posted by yomny

I had never seen this done much until now. It seems to be a common upgrade within our community. Why do some only upgrade their front brakes to Brembo, Stoptech, AP... and leave the rear setup stock? I would rather hear from people that have done so and their reasons why. I'm not a racing pro but with EBD(brake force thing) on modern cars wouldn't a strong bite upfront only cause the rear to act up? I also see that some front rotors are smaller than the rear, this is due because of the e-brake drum being within the disc?

Reflect on above post, you get a majority of your energy dissipation from the front. When you brake, you notice the weight transfers to front too right?

On another note, properly designed BBKs will have correctly sized pistons to ensure proper braking distribution.

A huge reason for a BBK is really meant for consistency due to additional mass for thermal loading. The BRZ/FRS actually has a really well sized front brake setup. You're not going to magically drop stopping distances. Stopping distances is more of a function of tires.

[yomny]

So its practical then to upgrade in this manner? I dont mind either option, just curious as to why i see it done more with this car than others. Which kits let you retain the emergency brake? Is is recommended then to use the kits with bigger discs up front?

[yomny]

Originally Posted by f0rge

The same reason almost all cars come from the factory with larger vented rotors in the front and smaller solid ones in the back, the front brakes do approx 70% of the braking.

I know the front does more braking hence bigger discs up front, but going to a BBK and retaining the stock rear is not the same proportion as manufacturers design.

[BlueDubbinTDI]

Because most cars are heavily front biased under breaking IIRC

[Guillaume]

Don't take this the wrong way, but your ignorance on the subject (nothing wrong with that) tends to indicate you don't need bigger brakes. Why do you think you need bigger brakes?

Everyone pretty much agrees that with a stock motor, decent (read "sporty") pads and discs for the OEM set-up are more than enough, even if you get regular track action.

[yomny]

Originally Posted by CSG David

Reflect on above post, you get a majority of your energy dissipation from the front. When you brake, you notice the weight transfers to front too right?

On another note, properly designed BBKs will have correctly sized pistons to ensure proper braking distribution.

A huge reason for a BBK is really meant for consistency due to additional mass for thermal loading. The BRZ/FRS actually has a really well sized front brake setup. You're not going to magically drop stopping distances. Stopping distances is more of a function of tires.

Everything stated and mentioned still leaves me wondering as to why only upgrade the already bigger front disk to an even bigger one with more stopping power. I know traction is everything and nothing can substitute it, given that's constant, a front bbk only would cause more weight distribution, more ABS function and more everything.. My doubt here is, is it wise to just upgrade the front or to retain proportion and upgrade both, if money weren't a factor.

[yomny]

Originally Posted by Guillaume

Don't take this the wrong way, but your ignorance on the subject (nothing wrong with that) tends to indicate you don't need bigger brakes. Why do you think you need bigger brakes?

Everyone pretty much agrees that with a stock motor, decent (read "sporty") pads and discs for the OEM set-up are more than enough, even if you get regular track action.

Seriously, now my question is being ignorant. Who told you i wanted or needed bigger brakes?

[yomny]

People lets focus here... Its just a simple question except for @CSG David i dont think there are many experts here. I simply asked why is it so popular to only upgrade front brakes on this car as compared to others. Please if you have nothing better to do than come on threads and flame it to death.. get lost!

Back to basics, read the question and answer it, in parts if you must. This isn't a critical thinking question or a topic for you wise man to elaborate on..This only applies to the ones with the smart remarks, everyone else i appreciate your input. How is anyone suppose to learn, make decisions with arrogant dope heads replying in such ways.

[yomny]

Originally Posted by choi0706

smaller in diameter?

on some kits (not sure about frs/brz) you loose the parking brake going with bbk in the rear..

Yes sir, i've noticed a lot of them have a smaller disc in diameter up front.

example:
Front-StopTech ST-40 Red Calipers with 328x28mm Slotted Rotors
Rear-StopTech ST-22 Red Calipers with 345x28mm Slotted Rotors

[enwave]

Different strokes for different folks, but here's my opinion on the matter:

Stopping faster shifts more weight up front, meaning there is less friction on the rear tires (less downforce/weight, less friction). For many people, especially on stock/looser suspension, you're not using the rear brakes as much. Because of that, many people don't see the need to upgrade the rear brakes. The bigger the bite in the front, the less you actually use the brakes in the back.

This can lead to some funky behavior for sure, if you're not used to driving that way. The car can become a little extra tail happy under braking, and often braking distance can actually decrease.

However, with a good stiff and flat suspension setup, you can help with some of that weight shift (a little). I think many people hit the zone where their suspension is stiff enough to help keep those back brakes doing some work, but not stiff enough to where the back brakes need more love.

If your car (theoretically) stayed perfectly flat all the time, upgrading all four is definitely necessary. In any other situation, you just need to find the right balance of front/back distribution. Once the suspension is modified, that can change very quickly. Size of the front brakes also matters. There are a lot of good articles out there about this subject if you're looking to read a little more about it.


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[Guillaume]

Originally Posted by yomny

Seriously, now my question is being ignorant. Who told you i wanted or needed bigger brakes?

Huh, I just assumed it (wrongly so, it appears).