FAQ: Vibration under braking: warped rotors? NO!

[djerickd]

KNS Brakes

 

[dddd]

Just curious - I've seen the Euro pads mentioned here, and some have gone that route. Are they the same as the Australian pads, or different yet again? What about KDM spec pads?

I checked my pads and they are FG rated ( I believe EU is rated GG and are semi metallic) which means they are ceramic, same as USA, and yes I have the brake shudder issue also

 

[Waynerm002]

Haven’t been in this post in a bit but based on my experience, the vibration goes away on its own somewhere around 10k miles. I remember reading about this in a review or maybe it was a video review. I replaced my pads and it was still there but minor. I had forgotten about it as I was so busy with work until my buddy who was looking to upgrade his pads asked me how mine is doing (he saw the same review), on my drive home I noticed it wasn’t there anymore. With the brake pad change, it certainly reduced the vibration but the pads squeak at low speed, while having really good stopping power. I didn’t mine the trade off as it made the car feel better. I went with the Stop Tech versions.

 

[Rennokas]

I have EU GT model and breaks are squeeeky and not smooth.

 

[djerickd]

I have EU GT model and breaks are squeeeky and not smooth.

You can probably sell them to someone on here

 

[Rennokas]

You can probably sell them to someone on here

US has it worse?

 

[SeanFL]

That's what some believe. When Car & Driver magazine had significant trouble with their Stinger on the track, I believe Kia put on the European pads and they did much better stopping the car after some high speed runs. Search for "Car & Driver a23132712" and you'll find their story about the lightning lap. I tried to put the link here but I'm not able to post the link due to forum settings.

Maybe someone else can shed light on if those EU pads lead to less deposits and brake shuddering long term.

 

[Rennokas]

It breaks fine, just the squeeking is annoying. Tried to clean with break cleaner, but suppose I have to take it apart and do a proper clean.

 

[MerlintheMad]

It breaks fine, just the squeeking is annoying. Tried to clean with break cleaner, but suppose I have to take it apart and do a proper clean.

The Stinger manual warns that "high performance Brembo brakes" are noisy sometimes. That "scratching, rrrr sounds are normal operation". I've quoted the part verbatim several/many times on the forum (that is not a direct quote, only a paraphrase from memory: I am in haste at the moment).

 

[Helo58]

That's what some believe. When Car & Driver magazine had significant trouble with their Stinger on the track, I believe Kia put on the European pads and they did much better stopping the car after some high speed runs. Search for "Car & Driver a23132712" and you'll find their story about the lightning lap. I tried to put the link here but I'm not able to post the link due to forum settings.

Maybe someone else can shed light on if those EU pads lead to less deposits and brake shuddering long term.

In the latest "Lightning Lap" (NOV2019 issue), the Genesis G70 was around 5 seconds faster around VIR than the Stinger. The article suggests that this is entirely due to better braking performance of the G70 vs the Stinger with the cars being so similar otherwise. They specifically mention the Stinger going off-track during the previous testing of the Stinger at Lightning Lap.

 

[G70 Owner]

In the latest "Lightning Lap" (NOV2019 issue), the Genesis G70 was around 5 seconds faster around VIR than the Stinger. The article suggests that this is entirely due to better braking performance of the G70 vs the Stinger with the cars being so similar otherwise. They specifically mention the Stinger going off-track during the previous testing of the Stinger at Lightning Lap.

Just so you guys know...since we discussed this on our side too. We think C&D got their wires crossed when they were writing that. The Stingers time was set with euro spec pads after it went off track. The g70 dynamic they tested also comes with euro spec pads. So pads and braking systems are exactly equal between the cars during their testing. Weight and suspension tuning could be the only factors coming into play for that 5 second lap time gap. I think if they had run a sport trim (which comes with normal pads) we would have seen them do the same thing they did with the Stingers first outing

 

[Helo58]

Just so you guys know...since we discussed this on our side too. We think C&D got their wires crossed when they were writing that. The Stingers time was set with euro spec pads after it went off track. The g70 dynamic they tested also comes with euro spec pads. So pads and braking systems are exactly equal between the cars during their testing. Weight and suspension tuning could be the only factors coming into play for that 5 second lap time gap. I think if they had run a sport trim (which comes with normal pads) we would have seen them do the same thing they did with the Stingers first outing

From the article, "Foot down. Pedal feels solid. The car sheds 92.7 mph like it's nothing. Easy. Apparently, luxury-brand Genesis fits its sports sedan with track-worthy pads as standard equipment (the Kia required accessory pads to safely record a fast lap). In fact, the G70's stoppers seem to enjoy the abuse. If you ever doubted the importance of good brakes, take a look at the over-one-second advantage the G70 holds over the Stinger after the first corner. The majority of the 4.3-second difference between these cousins' lap times occurs in VIR's brutal braking zones."

I get what you are saying, but they acknowledged the brake change on the Stinger to get the fast lap and still attributed the difference in lap times to the brakes. Do you think it was a confidence issue? From personal track experiences, it would be for me. Not trusting your brakes will DESTROY your times. Also, it appears that the G70 is about 136# lighter than the GT2 (as equipped for this test), on the same tires, and using the same brakes(?). If not brakes, it appears as though suspension tuning is drastically different.

Quoted from the Stinger in 2018: "But competent brake pads don’t turn the soft if powerful Stinger into a track car. With its brake problem solved, the Stinger stopped embarrassing itself but still posted the second- or third-slowest segment time everywhere except sector five, where it topped the BRZ and Accord and tied with the Camaro 2.0T 1LE. Still, after we set our baseline time, the Stinger’s laps deteriorated. Its phobia of deep braking points and fast turn-in isn’t a sign that it’s a bad car. But it’s certainly not a track machine."

This seems to allude that the Stinger brakes still are horrible even with good pads.

 

[G70 Owner]

From the article, "Foot down. Pedal feels solid. The car sheds 92.7 mph like it's nothing. Easy. Apparently, luxury-brand Genesis fits its sports sedan with track-worthy pads as standard equipment (the Kia required accessory pads to safely record a fast lap). In fact, the G70's stoppers seem to enjoy the abuse. If you ever doubted the importance of good brakes, take a look at the over-one-second advantage the G70 holds over the Stinger after the first corner. The majority of the 4.3-second difference between these cousins' lap times occurs in VIR's brutal braking zones."

I get what you are saying, but they acknowledged the brake change on the Stinger to get the fast lap and still attributed the difference in lap times to the brakes. Do you think it was a confidence issue? From personal track experiences, it would be for me. Not trusting your brakes will DESTROY your times. Also, it appears that the G70 is about 136# lighter than the GT2 (as equipped for this test), on the same tires, and using the same brakes(?). If not brakes, it appears as though suspension tuning is drastically different.

Quoted from the Stinger in 2018: "But competent brake pads don’t turn the soft if powerful Stinger into a track car. With its brake problem solved, the Stinger stopped embarrassing itself but still posted the second- or third-slowest segment time everywhere except sector five, where it topped the BRZ and Accord and tied with the Camaro 2.0T 1LE. Still, after we set our baseline time, the Stinger’s laps deteriorated. Its phobia of deep braking points and fast turn-in isn’t a sign that it’s a bad car. But it’s certainly not a track machine."

This seems to allude that the Stinger brakes still are horrible even with good pads.

It could be a confidence issue, as ~150 pounds less weight will work the brakes less even when they are the same exact setup between cars allowing a driver to push them more. Year over year track conditions also will not be exactly the same so that could account for a second or two of that 5 second gap

 

[Helo58]

Year over year track conditions also will not be exactly the same so that could account for a second or two of that 5 second gap

There is a sidebar topic in the C&D Lightning Lap article that I think says the difference on their test car between optimal conditions and least optimal conditions was 2.7 seconds (I think). Same car, same track, same driver, but different day or time of day. Interesting!

 

[D.J.]

No, the rotors are not warped. The pads Kia used "melt" and leave material deposit build-up on the rotor surface. The bedding procedure removes those deposits.

A higher quality ceramic pad will not leave the material deposits. I am using Centric Posi-Quiet ceramic pads and flawless performance.

Which PN of Centric pads are you using?

I agree with everything you are saying - just wanted to add the the pads Kia used are in fact Brembo pads. These are from my 2018 Stinger in Canada

Just had my front pads and rotors replaced under warranty along with a new head unit. This is after an initial visit where they stated they would not replace under warranty (even though the car only had ~3k miles at the time in less than 8 months of use). They offered to cut the rotors but I declined. We'll see how far these go until there's an issue again.

Why the new headunit? - Curious

 

[D.J.]

I just had all 4 rotors replaced under warranty at 10,320 kms.
Just rotors - not pads.

Durham Kia - Oshawa, Ontario

They are smooth - for now...

I had all 4 rotors replaced AGAIN the 2nd time at 23,774 kms. Seems I this car needs rotors nearly a much as oil changes.
The replaced the rotors with no questions asked...

 

[itguy61]

Replacing rotors is a temporary fix without different pads.

 

[JVsGT]

Replacing rotors is a temporary fix without different pads.

Dealership offered to cut my rotors with about 13k miles as a "courtesy". Of course their diagnosis is warped rotors. They said they could install my Stoptech pads for $25 but can't warranty anything. I figured that would be better than just cutting the rotors and putting the same OEM pads back on.

 

[itguy61]

I agree. Not sure what they can warranty anyway as the don't warranty pads or rotors after 12k miles. Brake friction parts are just consumables anyway.

 

[Metalmania82]

Why the new headunit? - Curious

There's a common issue where the FADE setting for some reason reverts itself to rear speakers only. You can go in and change it to where you like and then a couple of startups later, go to check again and the FADE is in the rear again. SOMEHOW, this couldn't be solved with just a software update, had to have the h/u replaced with whatever latest software they have.
So far so good!