Installed rotors and pads, now too much vibration, wear pattern is odd, help needed.

Update
Got a call from Pat McCleish at StopTech.
He explained that using the StopTech brake-in procedure was directed at drivers who plan to track their cars.
He suggested that for normal use that particular break-in procedure wasn't needed.
He pointed out that Honda didn't prescribe a break-in procedure for the stock NSX and oem brakes work fine.

Meantime I've had my NSX rotors turned at the Acura dealership to clean them up and will put them on in the new year.
 
I also installed stop tech cross drilled and slotted rotors front and rear before the nsxpo. I found the holes didn't line up either. I contacted them and they said it was a error of which holes got threaded vs which got beveled. I beveled the drilled and threaded holes they line up perfectly to the rotor screws. I don't know if that had any thing really to do with your issue thou. This is more to address the screws not lining up. My setup has been great so far, I did the hawk hps pads and did the break in process and ate super blue along with stainless lines. I only have maybe 2000 miles on my setup so far. Hopefully milling will solve your issue.
 
An update on my brakes:

I had the dealership turn the Stoptech rotors down to make them uniform thickness.
I sanded the new oem brake pads to remove any glazing and/or buildup.
I did not follow the Stoptech pad break in procedure, instead drove the car normally and all is well so far.

I think the problem stemmed from using the aggressive pad break in procedure from the StopTech website on oem pads.
This resulted in a buildup of pad material on the rotors and perhaps some rotor warping as well.

Next time I'll go back to oem rotors.
I had over 90 k miles on my original oem rotors with no trouble at all.
 
Last edited:
I've got a note to add to this as others may look to this thread when experiencing the same issue.

I was told by a fairly savy track technician that often very aggressive vibration is actually due to uneven metallic properties in the rotors themselves. The sensation feels like "warped rotors". The aggressive vibration is felt under light-mid breaking.
The best example is a long downhill road with a stop light at the bottom. While decending, one is riding the breaks to slow down, this heats up the breaks quite uniformly. Upon reaching the bottom, one must stop at the red light. When stopping, the rotor is allowed to cool all but the rotor still being squeezed by the pads. If the rotor was heated hot enough, and the pads were held on a single porton of the rotor for too long, the rotor properties will be slightly different in that one section.

When lightly breaking, the difference in friction in the rotor is apparent. However, under heavy breaking, the vibration disappears since the rest of the rotor is becoming more & more uniform with heat. I can personally attest to this.

The solution to this problem (if you think this is the case) is to do some high speed driving on a track with some heavy breaking followed by light driving with minimal breaking (sort of like heat cycling the breaks). The theory is that with each heavy brake, the rotor is becoming more uniform. Then, by allowing a cooling period, the rotor is allowed to cool evenly. Rinse-lather-repeat until the vibration has disappeared under light breaking.

Not sure if this is the case for you Jim, but if vibration comes back, your rotor's might be metallurgically uneven due to something like the long-hill stoplight scenario.

Has anyone else heard of this theory?

Lucas
 
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JD Cross and BrianB, I just want to confirm that you're not crazy. I've had a new set of Centric/Stoptech rotors (mine are cross-drilled) here for a few months and just got around to installing them today. My front rotors have exactly the same problem - the wrong holes are countersunk for the set screws. Front rotors only, the rears are fine. I'll countersink the second set of holes next thing, but what a PIA. I wonder how many rotors Stoptech sent out this way?
 
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To me, Stoptech should have replace all of them, regardless.
 
Agreed, but two minutes of countersinking kept the project moving.
 
I'm surprised people continue to buy the OEM pads. I'm sure there is nothing wrong with them, but if you street your car only I find a set of powerstop evolution ceramics work fantastically well. And they are full ceramic. 22 dollars on RockAuto with new clips and springs.
 
An update on my car.
After sitting out the winter I drove the NSX yesterday for a 40 mile trip.
The vibration on braking has returned despite the rotors being turned and the pads being deglazed.

I'm more convinced than ever there something wrong with the Stoptech rotors and will be emailing Pat MacLeish at StopTech to try and resolve this.
Perhaps it is a metallurgical or design matter?
Something in the metal that StopTech uses or their design that is not stable under heat and pressure.
I wonder if anyone else has experienced this?
 
Tangoman said:
I'm surprised people continue to buy the OEM pads.
Click to expand...
I'm not. The OEM pads have it all. Because they are designed specifically for the NSX, they can stand up to the heat of the racetrack (or high speed driving elsewhere), and they offer great stopping performance. They also offer relatively low dusting.

Every "generic" brake pad I've seen - meaning, designed for a wide variety of vehicles (including the Legend and other Acura models, whose pads are the same shape/size as the NSX's) - and especially those crappy ones you get for twenty bucks at the auto parts store - will NOT stand up to high-speed driving, and will NOT offer stopping performance as good as the OEM pads. There are high-performance aftermarket pads available from quality manufacturers like Hawk, but you won't find them for twenty bucks.
 
Update

I emailed Pat McLeish at Stop Tech advising him of the return of the problem.
I've suggested they send me two plain (not drilled or slotted) rotors correctly drilled and countersunk for NSX fitment.
I'll install those rotors, find out if they perform better, and report back to him and this forum.
 
I'd also send him a link to this thread, to make sure he understands a large audience is seeing this. If they have an error, they should take responsibility and correct it.
 
Dave
I did send him a link to this thread.
Not sure if it will help but can't hurt.
 
Update on StopTech
No reply from Pat McLeish at StopTech. He may no longer be there.
No reply from the StopTech support email address either.
 
Update
Mark Cornwell from StopTech has contacted me and after reviewing the file has told me StopTech will warranty my rotors.
He has also offered a lot of technical advice including brake pads to match the new rotors.
I am pleased they are coming to my rescue and hope this will fix my brake problem.
 
As Ken mentioned a lot of the technical info is on their website
Mark Cornwell did add that he has seen some changes in oem brake pad compounds over time.
He believes some oem pads today are not the same compounds as originally came from the factory.
For my application which is street and highway driving he suggested their Posi-Quiet Ceramic pads as an alternative to current oem pads.
 
Final Update

I installed the new front StopTech plain rotors that they warrantied and their recommended StopTech Posi-Quiet pads which they sold me at their jobber price.
The difference is like night and day, the NSX is back to normal, and I'm very pleased with the support from Mark Cornwall from StopTech
 
That's great!! Good to know they stand behind their product. I still haven't had a issue with my cross drilled and slotted rotors. Must of just been something with the set you received? Did they happen to say why you were having issues?
 
BrianB said:
That's great!! Good to know they stand behind their product. I still haven't had a issue with my cross drilled and slotted rotors. Must of just been something with the set you received? Did they happen to say why you were having issues?
Click to expand...

Mark Cornwall from StopTech felt it might be the interaction between the slotted rotors and oem pads.
He commented that oem replacement pads these days are not necessarily the same compound as the oem pads that came from the factory.
 

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