[David1]

For you guys running the Carbotech 1521 how are your rotors holding up? I just looked at a Supra that has had them on for 11k miles and the rotors are pretty groovy. They have some autox time on them and 1 HPDE day. What do your rotors look like and miles. I am about to order if they don’t eat the rotors like what I just saw.

[///MPhatic]

Originally Posted by David1

For you guys running the Carbotech 1521 how are your rotors holding up? I just looked at a Supra that has had them on for 11k miles and the rotors are pretty groovy. They have some autox time on them and 1 HPDE day. What do your rotors look like and miles. I am about to order if they don’t eat the rotors like what I just saw.

The 1521 is a pure street pad, and AFAIK unmatched in rotor friendliness (on the 2NH), as long as you're not doing something stupid, like Auto-X and HPDE's...

Street means street/canyons, not competition of any kind.

[HP Autosport]

Originally Posted by David1

For you guys running the Carbotech 1521 how are your rotors holding up? I just looked at a Supra that has had them on for 11k miles and the rotors are pretty groovy. They have some autox time on them and 1 HPDE day. What do your rotors look like and miles. I am about to order if they don’t eat the rotors like what I just saw.

Show us some photos. Some grooves are normal for heavy use.

[David1]

I’m not by the car now, but they are just super groovy like a vinyl record. They work fine.

[David1]

Here is a pic of how grooved they are but they work fine.

[///MPhatic]

I've seen that before, it's common, but I haven't seen it with the 1521.

[M3SQRD]

I have been using CT 1521 for 25 years on S2000s, an e46 M3, an e46 330ci, e92 M3s, a f22 240ix and a f82. I’ve used them in stock, AP Racing and PFC calipers. The 1521 are by far the friendliest street performance pads with minimal rotor wear. You can go thru at least two sets of pads before needing to replace rotors. However, I always properly bed new sets of pads and get a good pad transfer layer on the rotors so I have no idea what the wear is like on improperly bedded pads and rotors. They have excellent initial bite hot and even good initial bite when cold. I have quite a few friends that run these pads with similar results so I have no idea what’s caused the grooves in the rotors. Improper bedding? Aggressive braking with cold pads and rotors?

I would highly recommend them as a street-only pad. They are not be used in autox and on track. Their XP12 and XP20 track pads are great for the track; however, I’m a PFC-only track pad user since mid 2000s

[medphysdave]

I've only had them on for a couple weeks but if anything they look like they polish to rotors more than anything. Very gentle. I can't believe how little dust they produce. Two weeks of DD and my wheels still look clean. I had xp12s on the car prior and the 1521 has given me a few oh crap moments because they require more pedal pressure. I have brake coding done, so this may not be experienced with stock programming. Carbotech told me not to bed them and no need to scuff the discs because I was using the xp12. Overall I'm happy to be running this pad on the street. Rotors should last longer with this pad, no noise, low dust. They will stop you no doubt and I feel like some aggressive driving will be fine as long as you don't have a lot of quick hard braking. Give them a bit of time to cool and should be no problem. I don't think you'll have to baby the pad. Just be mindful that it will start to give. I haven't read any feedback on how this pad starts to let go when temps are exceeded. Is it gradual and then hits peak inefficiency like the stock pad, or does it completely let go so there is virtually no braking?

[///MPhatic]

Originally Posted by M3SQRD

The 1521 are by far the friendliest street performance pads with minimal rotor wear. You can go thru at least two sets of pads before needing to replace rotors.

The Akebono pads are better in every way, but sadly not made for the 2NH.

Originally Posted by M3SQRD

However, I always properly bed new sets of pads and get a good pad transfer layer on the rotors so I have no idea what the wear is like on improperly bedded pads and rotors.

This is interesting because CT told me NOT to bed the 1521 in, and that doing so would cause glazing. They recommended 300 street miles before hard use as the bed-in.

[medphysdave]

Originally Posted by ///MPhatic

The Akebono pads are better in every way, but sadly not made for the 2NH.



This is interesting because CT told me NOT to bed the 1521 in, and that doing so would cause glazing. They recommended 300 street miles before hard use as the bed-in.

Carbotech told me the same thing regarding 1521 bedding.

[M3SQRD]

Originally Posted by ///MPhatic

The Akebono pads are better in every way, but sadly not made for the 2NH.



This is interesting because CT told me NOT to bed the 1521 in, and that doing so would cause glazing. They recommended 300 street miles before hard use as the bed-in.

I disagree about Akebono pads being better. This shows the major issue with recommending pads because no two people are looking for the same thing from a pad.

Well, I’ve been doing this for close to three decades without issue. The problem with driving regularly for 300 miles could mean a panic stop at cold temp at mile 15 of 300 which could result in pad and/or rotor damage. I don’t bed them in the same way I bed-in a race pad. It’s fewer stops and from a lower speed delta. It results in a perfect uniform pad transfer layer. I’ll stick with my own experience with the pad.

[Distinct]

Any suggestions on where to buy Carbotech 1521 pads? Thank you.

[///MPhatic]

Originally Posted by M3SQRD

I disagree about Akebono pads being better. This shows the major issue with recommending pads because no two people are looking for the same thing from a pad.

For a pure street pad the Akebono dusts less, is more friendly on rotors, costs less, and works just as well. I've had them both, pure street and on The Dragon.

Originally Posted by M3SQRD

Well, I’ve been doing this for close to three decades without issue.

I don't doubt it, but for pure street the 1521 is obviously more aggressive than the Akebono.

Originally Posted by M3SQRD

The problem with driving regularly for 300 miles could mean a panic stop at cold temp at mile 15 of 300 which could result in pad and/or rotor damage.

It's unlikely that a single panic stop would glaze the rotor/pad, but it's possible.

Originally Posted by M3SQRD

I don’t bed them in the same way I bed-in a race pad. It’s fewer stops and from a lower speed delta. It results in a perfect uniform pad transfer layer.

Let us know the exact speed and number of stops. I'm happy to ask CT if it's a better way to do it than 300 street miles, since I recommend the pad weekly.

Originally Posted by Distinct

Any suggestions on where to buy Carbotech 1521 pads? Thank you.

Direct from Carbotech. They prefer phone calls to online orders. Just call them.

(877) 899-5024

[M3SQRD]

Originally Posted by ///MPhatic

For a pure street pad the Akebono dusts less, is more friendly on rotors, costs less, and works just as well. I've had them both, pure street and on The Dragon.

There’s no such thing as a dustless pad and if there is then it’s not stopping a car. Akebono pads are ceramic which have lower dust levels and much lower temp performance. Please show me one ceramic pad that starts to drop its CoF from about 175-200 F at a significant rate?

I don't doubt it, but for pure street the 1521 is obviously more aggressive than the Akebono.

Metallic by definition will be more “aggressive” and there are many levels of aggressive. 1521 is not even remotely aggressive as any of the so-called dual-purpose pads.

It's unlikely that a single panic stop would glaze the rotor/pad, but it's possible.

Ok. Sure, if that’s what you believe.


Let us know the exact speed and number of stops. I'm happy to ask CT if it's a better way to do it than 300 street miles, since I recommend the pad weekly.


There must be some serious reading comprehension issues because here’s what CT says about bedding 1521 pad compound:

Please note: The 1521 compound does NOT require bedding in. Put the pads on a clean rotor surface (like new) and drive normally for the first 300 – 400 miles. No special procedure is required. “JUST DRIVE THE CAR”.

The bedding process transfers friction material from the pads into the pores of the brake rotor. It also matches the microscopic contours of the pads and rotors to increase surface contact.Proper bedding of pads & rotors will result in greater performance, longer pad life & less rotor wear. Failure to properly bed in your pads could lead to friction materials chunking and breaking up. This could also lead to overheating your pads and causing them to glaze over resulting in the car not being able to stop or slow fast enough.

Considering you use/prefer ceramic pads, my bedding-in procedure doesn’t apply to you. What is the exact purposes of bedding-in pads and rotors? Let’s see if we even agree on the purpose before I share how I bed a pad I’ve been using for almost three decades, regardless of what CT says. I’ve worked with the owner of CT on a few projects over the years so I have a great understanding of the 1521 compound, going back to when it had different names. Also, I’m not going to list out one of my bedding-in procedures just to have someone perform it incorrectly and then try to put the blame on me. Property bedding pads and rotors require a precise procedure, if not followed will result in potentially glazed pads or overheated rotors. I find it interesting that you’ve taken an attacking posture on a simple pad recommendation that I have close to 30 years of practical experience with on vastly different cars and braking systems. Not sure why unless I do something different from what the pad manufacturer supposedly recommends?


Direct from Carbotech. They prefer phone calls to online orders. Just call them.

(877) 899-5024

If you recommend 1521 weekly, why aren’t you solely recommending the far superior, zero dust Akebono pads? I find that interesting and confusing.

I’ve been tracking for 36 years and over that time period I’ve learned a thing or two about street and race brake pads and it’s not always in agreement with documentation provided by pad manufacturers. If you have enough experience you should be able to modify and/or fine tune things based on your braking and driving styles. Will what I do work for everyone? Probably not. The key is to be able to threshold brake without engaging ABS. Engaging ABS is the worst thing you can do if you’re properly bedding-in brake pads and rotors.

The included photos show 1521 brake dust on wheels after 400-600 hard miles. Not sure why the second pic is rotated.

[///MPhatic]

Originally Posted by M3SQRD

If you recommend 1521 weekly, why aren’t you solely recommending the far superior, zero dust Akebono pads? I find that interesting and confusing.

First, I never said they were zero dust, I said they dust less than the 1521, and they do, I've had them both. I only recommend the 1521 over the Akebono because Akebono doesn't make a pad for the 2NH.

Originally Posted by M3SQRD

I’ve been tracking for 36 years.

I think this line says it all. I've also been driving since 1986, and have seen my fair share of tracks, but my opinion isn't skewed by being a track rat. You and I will have to agree to disagree...on everything, so this will be my last response to you.

Diamond Black BBS FI-R by Andrew Thompson, on Flickr

Jewelry. by Andrew Thompson, on Flickr

Holy Trinity. by Andrew Thompson, on Flickr

[M3SQRD]

Originally Posted by ///MPhatic

First, I never said they were zero dust, I said they dust less than the 1521, and they do, I've had them both. I only recommend the 1521 over the Akebono because Akebono doesn't make a pad for the 2NH.



I think this line says it all. I've also been driving since 1986, and have seen my fair share of tracks, but my opinion isn't skewed by being a track rat. You and I will have to agree to disagree...on everything, so this will be my last response to you.

Why are you showing multiple pictures of your BBS FI-R, or similar model, wheels? I was showing brake dust levels. I didn’t see you mention mileage and dust levels. Considering you said Akebono doesn’t make pads for the 2NH so are you proving 1521 don’t generate as much dust as you claim they do?

My experience goes well beyond tracking and I’ve been driving for more than 36 years. My background is technical so I have a better understanding of brake pads and braking systems in more advanced applications than cars. I guess you also missed when I said the 1521 bedding-in process is different from race pad bedding-in process.

Based on your ride height, it’s obvious you’re part of the stance crowd. BC dampers?

I guess you missed my latest update. Directly from CT so there must be reading comprehension issues:

Please note: The 1521 compound does NOT require bedding in. Put the pads on a clean rotor surface (like new) and drive normally for the first 300 – 400 miles. No special procedure is required. “JUST DRIVE THE CAR”.

The bedding process transfers friction material from the pads into the pores of the brake rotor. It also matches the microscopic contours of the pads and rotors to increase surface contact. Proper bedding of pads & rotors will result in greater performance, longer pad life & less rotor wear. Failure to properly bed in your pads could lead to friction materials chunking and breaking up. This could also lead to overheating your pads and causing them to glaze over resulting in the car not being able to stop or slow fast enough.

[M3SQRD]

Originally Posted by medphysdave

I've only had them on for a couple weeks but if anything they look like they polish to rotors more than anything. Very gentle. I can't believe how little dust they produce. Two weeks of DD and my wheels still look clean. I had xp12s on the car prior and the 1521 has given me a few oh crap moments because they require more pedal pressure. I have brake coding done, so this may not be experienced with stock programming. Carbotech told me not to bed them and no need to scuff the discs because I was using the xp12. Overall I'm happy to be running this pad on the street. Rotors should last longer with this pad, no noise, low dust. They will stop you no doubt and I feel like some aggressive driving will be fine as long as you don't have a lot of quick hard braking. Give them a bit of time to cool and should be no problem. I don't think you'll have to baby the pad. Just be mindful that it will start to give. I haven't read any feedback on how this pad starts to let go when temps are exceeded. Is it gradual and then hits peak inefficiency like the stock pad, or does it completely let go so there is virtually no braking?

So the rotor in the picture was used with XP12 before switching to 1521? The groves are likely due to the XP12 being used on the street driving to/from a track day(s) plus any additional street use of the XP12. When cold, the XP12 acts like a brake lathe when the pads are operating well below their intended operating temp range. Attempting to rebed-in the 1521 likely won’t remove the groves; however, it may provide more consistent braking. Using the XP12 at low pad temps likely removed the pad transfer layer so there’s currently no pad transfer layer (it appears that way in the picture). Send me a PM if you’re interested in a good 1521 bedding-in procedure.

[medphysdave]

Originally Posted by M3SQRD

So the rotor in the picture was used with XP12 before switching to 1521? The groves are likely due to the XP12 being used on the street driving to/from a track day(s) plus any additional street use of the XP12. When cold, the XP12 acts like a brake lathe when the pads are operating well below their intended operating temp range. Attempting to rebed-in the 1521 likely won’t remove the groves; however, it may provide more consistent braking. Using the XP12 at low pad temps likely removed the pad transfer layer so there’s currently no pad transfer layer (it appears that way in the picture). Send me a PM if you’re interested in a good 1521 bedding-in procedure.

Not sure. My use case was switch8ng from xp12 to 1521. Not sure what OP is running.

[M3SQRD]

Originally Posted by medphysdave

Not sure. My use case was switch8ng from xp12 to 1521. Not sure what OP is running.

Sorry! Got you and the OP mixed up.

How do your rotors look? Do they have a grayish color on the surface? If it looks more like bare metal then rebedding will help improve braking performance.

If you get used to the initial bite of the XP12, any pure street performance pad will require the leg pressure of an F1 driver to develop the same level of braking torque. It takes time to reacclimate from a race pad to a street pad.

[medphysdave]

Originally Posted by M3SQRD

Sorry! Got you and the OP mixed up.

How do your rotors look? Do they have a grayish color on the surface? If it looks more like bare metal then rebedding will help improve braking performance.

If you get used to the initial bite of the XP12, any pure street performance pad will require the leg pressure of an F1 driver to develop the same level of braking torque. It takes time to reacclimate from a race pad to a street pad.

My rotors look shiny polished at the moment. I've always had lite pedal habits which is why I thing xp12 on street was appealing. Low pedal pressure yielding nice bite. I start braking early and slow speed up to traffic lights as opposed to higher speed and hard braking

[medphysdave]

Here we go. Rear is the drilled rotor. A little less polished than I remember.

[M3SQRD]

Originally Posted by medphysdave

Here we go. Rear is the drilled rotor. A little less polished than I remember.

Front looks a little better than the rear. Rear has a faint layer of material. A rebedding procedure will likely improve your street braking and minimize the oh 💩 events. I ran the brake bias calculation of the 2NH brake setup and was surprised that the front is 67.6% vs. the f8x blue calipers and 380/370 rotors is 62.8% front. An almost 5% shift forward is significant. It explains why Essex created a kit specifically for the f87 M2C which is within 0.2% of the stock bias.