bigger wheels/tires = new brakes?

[shanec]

Since putting on 18x9.5 wheels with 255/45/18 up front and 285/40/18 in the back (GT500 sizes) - my front disks are showing hot spots....so says my tire shop guy. The discs to have dark swirls on them. He says they've been glowing at one time at least.

This is not a track car, just a DD.

I'm wondering if the extra rotating mass on these bigger wheels & tires is making it tough on my brakes.

Car seems to stop OK...but again, I'm not auto-x'ing it so I can't tell you whether or not the 100-0 stop distance has changed. LOL

 

[Ken04]

Since putting on 18x9.5 wheels with 255/45/18 up front and 285/40/18 in the back (GT500 sizes) - my front disks are showing hot spots....so says my tire shop guy. The discs to have dark swirls on them. He says they've been glowing at one time at least.

This is not a track car, just a DD.

I'm wondering if the extra rotating mass on these bigger wheels & tires is making it tough on my brakes.

Car seems to stop OK...but again, I'm not auto-x'ing it so I can't tell you whether or not the 100-0 stop distance has changed. LOL

more rotating mass is harder to stop than smaller, but, normally hot spots are from having hot brakes and hot pads clamped to hot rotors while being stopped. Worse thing you can do to disc brakes other than abusing them is to roll up to a stop when they're hot and keeping brake pedal pushed. I have a manual so if I'm on level ground at a stop, I let off the brakes. Even with an auto I keep creeping ahead little by little so I don't make hot spots and transfer hot pad material to the rotors. Which BTW is usually called warped rotors, which isn't. It's pad material built up that makes brakes pulsate, not warped rotors.

 

[shanec]

Thanks for that. I have a manual too and I'll try to do the same.

BTW, I have no brake pulsation or anything else strange going on other than hot spots on the rotors.

 

[shanec]

Just curious - when you apply the emergency brake, what's getting engaged? I assume it is not in the hydraulic system that could apply disc brakes but I don't know what else it could do since I have not noticed any brake drums either.

 

[Ken04]

Thanks for that. I have a manual too and I'll try to do the same.

BTW, I have no brake pulsation or anything else strange going on other than hot spots on the rotors.

a hot spot in one place can only be from your hot pads clamped to the rotor, right ? IIRC the e-brake is mechanical. It does clamp the pads to the rotor.