I think he's referring to the S190 chassis code of the Lexus GS (2005 - 2011).

 

Yes exactly👍

 

I can see the reason that the brakes in GS is larger since it is more of sport sedan instead of the luxury land yacht. GS is most likely to be driven harder than LS.

If you mean by shortcoming is vibration or pulsation, my LS with OEM parts stops smoothly without any vibration.

Not trying to argue here, understand that things (engine, brakes, handling, whatever) can be bigger/better/improved but kinda surprised to hear one describing the brakes in LS430 as ****. Anyone knows what is the stopping distance of LS vs other similar large sedans?

I am just not seeing how a slightly larger disc is going to improve braking noticeably, but someone can educate me here. It will add unsprung weight for sure.

I believe with everything else being the same, a wider and lower profile tire will improve stopping distance.

 

Would this be a bad time to interject that rotors do not warp, they become unsmooth? lol

(for example, how do rotors develop grooves, when the pad has never worn out)

 

the essence is a more modern rotor design, which cools faster than factory disks, for example: if I make a 200-0 quick stop on factory disks then they will become very hot and stop stopping, on gs disks I can do this 3 times in a row.

 

I think the "force" on the pads is nearly irrelevant regarding ability to stop the car. The anti-skid system will allow the pads to take whatever force is required to lock the wheel and then prevent it from just locking. That means regardless of the brakes, they are subjected to extract an equal amount of energy for stopping a car going at a certain speed under a panic situation where the driver jams the brake down and holds it until the car is stopped. The brake energy must equal the energy to stop the car. It the pads are located at a larger diameter on the rotors they will still be subjected to the same amount of energy. Since the rotors are subjected to extracting the energy at a bigger diameter, the rotors will have more area to extract the energy. That means that the only difference will be that the larger diameter pad location will not heat the rotor as much as the smaller diameter. If you're racing the car on a track you would want the brakes designs to have large rotors and pads to keep from warping the rotors and burning the pads as quick. Braking distance won't change until the rotors and pads deteriorate.

 

Just make an experiment for yourself, stop the car from 200 km / h to 0 km / h, and then accelerate again to 200 km / h, you won’t be able to stop as fast as the first time, no matter how much you would like it, because the wheels and pads are hot and no longer cope with their task, no matter how you press on the pedal.
Just think, if you argue according to your logic the anti-skid system does not matter what diameter of the discs, how many cylinders will press on the pads, it is so strong and reliable that it is possible to put reduced diameter rotors and calipers not 4 piston but 1 piston and with all this it will stop the car.

 

Can someone please explain if I am missing anything, but I never have any breaking beating or whatever is discovered here, does everyone else has this problem? I installed powerbrakes, both rotors and pads, and I love the quality of braking, there is no pulsation, just a nice braking sound from the pads. It smoothly brakes from any speed and I don’t feel the heating problem is anyhow exposed to diminish it.

 

show your rotors?

 

I have these installed for a year or so

 

The OEM discs are simply too small for this car if you regurarly overspeed. And I do.
The discs surface become uneven in 10 000 km (6 200 miles)
You never have this if you are a calm driver.
I have changed the OEM discs 3 times in 1 year.

 

I don't have any pulsation but to be real, I drive as if there's an egg between my foot and the gas and brake pedals.

Another thing I would note about Asian cars, it doesn't matter how big the rotors are, even 14". The pad does not sweep edge to edge like they do with German cars. There's always a big rust stripe that can be 1/3 of the possible swept area. To me, it would require a larger pad to even utilize what's already there from the factory.

 

...so let me get this straight, you are increasing rotor size, and swept area, spacing out the caliper, but utilizing the OEM UCF30/31 pad?

 

The problem is not in the area of the pads and caliper force, but in the fact that the disc overheats due to its small diameter and structural defect, as a result of which the disc is bent after a short time, this problem was fixed
only on subsequent models LS/GS

 

But you do realize long-term, what this will do, right? It's gonna leave the rotor grooved or lipped due to the pad not being matched to the rotor face. If overheating is what you're trying to mitigate, a better ventilated / slotted rotor that is the OEM size would be another option.