If the IS 350 kit fits then maybe there is a solution for the people wanting better brakes. I found the front kit for $4400. Comes with rotors, calipers, pads, steel lines, and all hardware.

 

Nope started doing it again yesterday once I started doing a couple of hard brakes from 220kmph to 140kmph.

How can you give a car with 500hp brakes like these, only Lexus knows.

I have driven my c63s atleast thrice as hard and never experienced this.

 

I think the brakes are perfectly fine for the car. The fact that you're having such a hard time again and again makes me wonder if it's user error.

 

You're repeatedly doing hard braking at 140 mph? I don't think this car was made for that. Even in a track setting there aren't many times when you will be hitting the brakes at 140 mph repeatedly.

You definitely qualify as an extreme use case. If your AMG can do it then better stick with that. This is not a Lexus equivalent AMG vehicle.

 

OP has literally told us he’s abusing the car several times and y’all are still wondering if it’s user error lol.

 

Yup, I would say you'd need to get the big brake kit or perhaps swap some RC F brakes on.

 

Which if you need for street driving, there are other issues at play. I think the brakes would be just fine with better pads.

 

I don't have any problems with mine per say but not sure my front rotors are showing this striation, only the front...maybe I don't brake hard enough? I will mention this to my dealer.

 

If you call twice repeatedly. Accelerated to 220kmph once, had to slow down. Then accelerated back to 220kmph again and had to slow down again, brake pedal started pulsating the second time.

happens every time the brakes warms up upon hard use.

The brakes on a car should match the power and weight figure of the car rather than how the car is meant to be driven. I get that it’s not an AMG, but it has 480hp. And once this car gets going, it’s not a slouch by any means, it gains speed pretty fast. Except it doesn’t have the brakes to match that power figure.

If it has the RCF engine, it should have gotten its brakes too. It’s not user error at all. Just bad engineering.

 

Mate, I've gone close to the same speed and had to slow down too, and my brakes are just fine.

 

We've listed some options for upgrading the brakes, so maybe you should try some of those. If you think you have a case to bring to Lexus, that's something you can try as well. Though I'm not sure what they can do about it.

 

Define "hard brake" for us, please. Are you engaging ABS? Traction? Tire squeal?

If none of the above, I think OP is right in being disappointed with the resultant disc thickness variation. For a $75k, 500hp vehicle, I don't think 137mph to 87mph braking is abuse of the vehicle.

No offense, but that's a pretty pathetic claim given the automotive tech available in the year 2022.

OP, have you had the rotors looked at? Did they check for any hub runout? Next time you have rotors installed, make sure they write down on on the work order what is the stated disc runout of the entire assembly. Or better yet, spend $40 on amazon and get your own gauge to measure it. Check YouTube on how to do this.

It's probably an edge case, but if you've got a bad hub, or the rotor was out of spec in the first place, it won't matter how you drive it. We're only talking variations no thicker than a Post-It note which can result in what you're experiencing.

With all that being said, I regularly take off-ramps in a similar manner of driving as what you're describing. Probably closer to 100mph to 60 in a very short distance, but the same physics apply. Original rotors are still kicking with over 95k miles on them.

 

Heat causes expansion and will exacerbate any already-existing disc thickness variation.

I don't want to impugn anyone here, but it is possible the Lexus techs just don't know what they're doing. Any number of things can cause what you're experiencing. Poor brake job, over-torqued wheels, too much rust build-up on rotors in-between drives. Did you bed the new pads into the new rotors after the install? Can you describe exactly everything from when you picked the car up from the dealer to when you did those two braking maneuvers? It would go a long way in diagnosing this.

This is not a problem unique to Lexus, either. Same thing will happen with Brembo. Check the Audi forums for complaints about brake judder.

 

OP is seemingly the only person with these persistent issues, suggesting the cause is something unique to him.

 

Can anyone confirm the correct OEM Part Numbers for IS500 OEM Rotors + pads?