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Discussion Starter #1
I need front rotors for my 2018 STI. Turned them when I installed track pads and they machined down to just above minimum thickness after 20K highway/street miles. No way I'm buying the replacement Brembo rotors as they wore way too fast under street driving and they are more expensive than any of the higher end rotors currently offered.

After my single trackday with XP12's and the rotors just above min thickness, they are cracking around the drillings. Swore I wouldn't buy another drilled set, but these StopTech's are very affordable at $120 each. Has anyone used them, street or track? I know this is low probability given the newness of the 6 pots, but speak up if you have used them on your 18+, or even earlier years for comparison.

If I don't try these, I'm going to buy the Girodiscs. Larger upfront investment, but replacement rings are cheaper than slotted DBA's if I am going to go through rotors on the track.
 

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I am sure you are already well aware that if you track on any sort of regular basis, you should stay away form drilled and go with slotted rotors. I have had StopTech slotted rotors in the past on my other cars, and they have held up very nicely.
 

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Discussion Starter #3
Yeah,
I had another chat with Ken at KNS today and he said the same thing when I asked about the Stoptechs. He also said they are on backorder everywhere, anyway and he has DBA 4000 Blanks made for KNS that are the same price as the Stop Tech's, but with high quality DBA iron and pillar vane setup.

I just ordered a pair of those (Fronts) to try out at Laguna Seca in August. My factory drilled Brembos are at minimum thickness and cracking around most holes right now, after 1 track day. Worth it to try blanks for $250/pair to see how they hold up, before I throw down $800-900 on Girodiscs. I would not even bother buying the DBA 4000 slotted since they are over $600 a pair and I can get replacement Girodisc rings for $550 a pair and the advantage of rotating mass reduction and floating rotor design. If the blanks do well, I'll just leave the XP12's in all the time, so I don;t have to swap pads after track days. Just bleed before and drive.
 

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Just curious i've got a 2019 STI & the brakes are fine I have 14,000 miles on the car. Since May the brakes squeal so much it is really annoying me & considering on getting new rotors as well.
 

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Yeah,
I had another chat with Ken at KNS today and he said the same thing when I asked about the Stoptechs. He also said they are on backorder everywhere, anyway and he has DBA 4000 Blanks made for KNS that are the same price as the Stop Tech's, but with high quality DBA iron and pillar vane setup.

I just ordered a pair of those (Fronts) to try out at Laguna Seca in August. My factory drilled Brembos are at minimum thickness and cracking around most holes right now, after 1 track day. Worth it to try blanks for $250/pair to see how they hold up, before I throw down $800-900 on Girodiscs. I would not even bother buying the DBA 4000 slotted since they are over $600 a pair and I can get replacement Girodisc rings for $550 a pair and the advantage of rotating mass reduction and floating rotor design. If the blanks do well, I'll just leave the XP12's in all the time, so I don;t have to swap pads after track days. Just bleed before and drive.
In reality, unless you upgrade to Girodisc or something equivalent, blank discs are just fine even for track events. That's because today's brake pads does not produce as much gases like decades ago. With that being said, if Girodisc is within your price range and if you do track often, especially at a place like Laguna Seca, I would recommend that you to just go ahead with the Girodisc. While you are at it, consider changing to SS brake lines and cylinder bracket for better feel if you have not already done so.
 

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Just curious i've got a 2019 STI & the brakes are fine I have 14,000 miles on the car. Since May the brakes squeal so much it is really annoying me & considering on getting new rotors as well.
Unless the pads and/or rotors are truly worn out, try re-bedding them first.
 

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Discussion Starter #7
In reality, unless you upgrade to Girodisc or something equivalent, blank discs are just fine even for track events. That's because today's brake pads does not produce as much gases like decades ago. With that being said, if Girodisc is within your price range and if you do track often, especially at a place like Laguna Seca, I would recommend that you to just go ahead with the Girodisc. While you are at it, consider changing to SS brake lines and cylinder bracket for better feel if you have not already done so.
Budget for tracking right now is aimed at tires since I think I only have 1 more event left in the current set. Otherwise, I would have just gone Girodisc now. I'm thinking this winter, I'll upgrade front rotors, have the caliper cerakoted, and I'll do SS lines at the same time. I installed the Perrin M/C Stiffener within a week of buying the car. The firewall flex is pitiful. I consider this to be one of the 1st upgrades you should do for any STI.
 

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Just curious i've got a 2019 STI & the brakes are fine I have 14,000 miles on the car. Since May the brakes squeal so much it is really annoying me & considering on getting new rotors as well.
I would take a close look at the rotors to see if they have excessive wear. Myself and others have noticed that the factory rotors wear extremely fast, and pads show little to no signs of wearing. With 20K miles on my car, the rotors were worn to minimum thickness, but pads looked to have 75% life left in them. Unfortunately, I did not notice until I installed race pads for the track. I've seen here on the forum where people took the car in and Subaru replaced pads and rotors under warranty. Its worth taking them in to be inspected if you see excessive wear on rotors. That said...these are high performance brakes and it is normal for them to make some noise at low speed braking.

Snap some pictures of your front rotors and put them here. Take some close pictures showing the outer and inner edges of the rotors and I'll be able to tell you if the front rotors are worn.
 

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I would take a close look at the rotors to see if they have excessive wear. Myself and others have noticed that the factory rotors wear extremely fast, and pads show little to no signs of wearing. With 20K miles on my car, the rotors were worn to minimum thickness, but pads looked to have 75% life left in them. Unfortunately, I did not notice until I installed race pads for the track. I've seen here on the forum where people took the car in and Subaru replaced pads and rotors under warranty. Its worth taking them in to be inspected if you see excessive wear on rotors. That said...these are high performance brakes and it is normal for them to make some noise at low speed braking.

Snap some pictures of your front rotors and put them here. Take some close pictures showing the outer and inner edges of the rotors and I'll be able to tell you if the front rotors are worn.
I have an appointment with the Subaru dealer service department next week regarding the brake squeal. I will keep you guys posted.
 

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Just an update i had the Subaru service department inspect the brakes today. My car currently has 15,900 miles.

According to the technician: Front pads are worn down to 4mm & front rotors are uneven. However, the rear pads & rotors are fine & have 7mm left. The car is bone stock with just a catback exhaust. I don't track or drag race the car, just spirited driving on the weekends & the service advisor mentioned the brakes were abused so warranty will not apply here.
 

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Discussion Starter #11
You have a shit dealer. If you don’t have another option, I would contact Subaru of North America. If your calipers are still neon green, then there has been no abuse on your front brakes. It’s amazing how polarizing the dealers and advisors can be. 15000 miles is not a normal service life for front brakes. When you say rotors are uneven, do you mean warped or just worn uneven?

if warped, then I might see why they are saying abused. They are huge rotors and should not easily warp. But unevenly worn would indicate potential caliper problems.
 

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You have a shit dealer. If you don’t have another option, I would contact Subaru of North America. If your calipers are still neon green, then there has been no abuse on your front brakes. It’s amazing how polarizing the dealers and advisors can be. 15000 miles is not a normal service life for front brakes. When you say rotors are uneven, do you mean warped or just worn uneven?

if warped, then I might see why they are saying abused. They are huge rotors and should not easily warp. But unevenly worn would indicate potential caliper problems.
My calipers are still neon green. Now the front rotors the technician mentioned "rotors have mirror finish & are very uneven." Oh & I was quoted just front rotors & pads including parts & labor = $1,435.81 lol..

But really though once the time comes I really want to get 4 new rotors & pads either Stoptech or DBA. They have to be slotted & NOT drilled. I really want a good set that does not squeal. No way I am paying Subaru service for the same OEM rotors & pads.
 

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Discussion Starter #13
If you want better quality rotors without braking the bank, just buy the DBA KNS blanks. Front rotors are only $120 each, just no slots. Unless you are planning to track the car, your not really going to benefit with the better bite that the slotted rotors will provide. You’ll just probably wear through pads quicker.

I just replaced my fronts with the same KNS DBA4000 blanks (my OEM Rotors were at min thickness at 20,000 miles and one track day on race pads caused them to crack all over) and I track my car. I spoke with a Ken at KNS and just mentioned that I didn’t have budget at the moment to go Slotted and he said he has other customers tracking the blanks with no issues. I will run Laguna Seca at the end of the month, so we will see.
 

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If you want better quality rotors without braking the bank, just buy the DBA KNS blanks. Front rotors are only $120 each, just no slots. Unless you are planning to track the car, your not really going to benefit with the better bite that the slotted rotors will provide. You’ll just probably wear through pads quicker.

I just replaced my fronts with the same KNS DBA4000 blanks (my OEM Rotors were at min thickness at 20,000 miles and one track day on race pads caused them to crack all over) and I track my car. I spoke with a Ken at KNS and just mentioned that I didn’t have budget at the moment to go Slotted and he said he has other customers tracking the blanks with no issues. I will run Laguna Seca at the end of the month, so we will see.
Just curious with your new KNS set-up. Do they squeal once pressing the brake pedal?
 

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Just curious with your new KNS set-up. Do they squeal once pressing the brake pedal?
Well, yes, but I have race pads installed at the moment so that is expected. I haven’t run street pads on these rotors yet. I literally installed them yesterday and just bedded them in today.

I strongly suggest you contact Ken at KNS Brakes to discuss your application and questions. He’ll steer you in the right direction.
 

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Ken is the bomb. Literally he gets calls from all types of racers every day. Definitely knowledgeable and willing to help.
Well, yes, but I have race pads installed at the moment so that is expected. I haven’t run street pads on these rotors yet. I literally installed them yesterday and just bedded them in today.

I strongly suggest you contact Ken at KNS Brakes to discuss your application and questions. He’ll steer you in the right direction.
 

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Discussion Starter #17
Just curious with your new KNS set-up. Do they squeal once pressing the brake pedal?
Also to add, brake squealing has almost nothing to do with rotor material and design. Has to do with Brake Pad materials and design. Most street pads have design features such as dust channel and edge chamfering to reduce squeal. You can also get squeal from pad vibration against the pistons, so people of tend use shims and materials to try and dampen the sound from this vibration. This is not to be confused with Titanium shims, which are meant to insulate brake pistons and fluid from the extreme temps on the brake pads.

Not to be a dick here, but if you are buying a performance car, its going to be equipped with performance oriented brakes, which often have squealing noises because function is paramount over niceties. I don't understand why so many people complain about brake squeal and then look for pads that will be quiet, but often sacrifice on what they are meant to do. The same goes for brake dusting. These are things that go hand in hand with high performance brake parts...
 
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