Quick review: 034 front brake rotors

[Cool_Breeze]

UPDATE 10/29/21: An inspection this week revealed that both front rotors have cracked. It's unclear when it started or exactly why, but the kind people at 034 are replacing the rings at no cost and in good faith. I'm really impressed with how they're standing behind their products! To Jeff_Jeske's point in the comments, I'll run with XP12s instead of DS2500s on the track to help use the brakes in shorter bursts, as well as turn XDS off. Hopefully these can help keep temps down and increase rotor life. Overall I still love these rotors, appreciate 034's support, and will keep working on my skills. Since I don't see many reviews on these rotors I thought it was prudent for me to share, and I'll keep updating this post as I progress.



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I've done three track days, about 40-50 laps total, and they've been solid. They cool quickly - by the time I finish the cool down lap then get out and measure, the outer edge is only 500F and the inner roughly 350F. I'm still on street tires. Zero warping or brake judder, HOWEVER something nobody mentioned is the buzzing the J-slots can make. Whether coming to a stop light or hard into a turn, it sounds like thick tire treads smushing into the ground. 034 explains it's the heat outgassing, and their site claims it reduces noise compared to slotted rotors. It's not horrible, but just something I wish I knew. Anyway, aside from that they're performing very well. Btw, I've bedded these with Ferodo DS2500 pads, which are known to squeal, but with this setup there is absolutely zero squeal which I love. I might start swapping with dedicated track pads, but for now I love them!

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[rodacollier]

Sure nice that you shared that insight. You going to put the matching rear on next ?

My front OEM rotors have made faint ticking noise after I put 2k miles on the car and now I’m at 17k. Two dealers told me the noise was normal and gave me the degassing explanation. I don’t track the car and I’m itching to replace all four rotor & pads even though they look fine.

[Cool_Breeze]

My front OEM rotors have made faint ticking noise after I put 2k miles on the car and now I’m at 17k.

Are you noticing that ticking noise at lower speeds? If so it's totally normal, others have posted about it and I noticed it too. For the rears, not sure it's worth it, they hardly do anything. I think I'll stick with stock rotors and maybe some pads with more bite.

[DanMPower]

I did the front and rear kit on my RS3 and I also noticed the "slight" buzzing noise when coming to a stop. Only really hear it when I'm next to another car or a wall, doesn't bother me at all and I really have to listen carefully for it. I don't track my car but I wanted to save some weight plus add to the "cool" factor and they definitely did the trick. The fronts saved 7.5lbs each and the rear rotors even though much bigger is lighter by 1lb compared to the tiny stock rotor, but once you add in the weight of the new bracket which is exactly 1lb heavier than stock, it's a wash. So far I did a couple of hard stops from doing 60-130 runs and they stopped incredibly well and straight. Love them so far.
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[Arelax]

With the stock rotors I used to hear the buzzing/ticking noise all the time. Someone once told me it was because they were drilled.

After I switched to Girodisc rotors I don't hear it anymore. whatever it is, it had something to do with the rotor.

[A4 Centaur]

I've been following the J-Hook rotors for a while now and the reviews are interesting. Has anyone measured the actual rotor diameter? Wondering if they are 370mm or larger/ smaller?

http://apradical.stillen.com/brake-t...k-brake-rotors

[Cool_Breeze]

I've been following the J-Hook rotors for a while now and the reviews are interesting. Has anyone measured the actual rotor diameter? Wondering if they are 370mm or larger/ smaller?

http://apradical.stillen.com/brake-t...k-brake-rotors

They're stated as 370, but I haven't actually measured it, now I'm curious... 🤔

[Cool_Breeze]

I've been following the J-Hook rotors for a while now and the reviews are interesting. Has anyone measured the actual rotor diameter? Wondering if they are 370mm or larger/ smaller?

http://apradical.stillen.com/brake-t...k-brake-rotors

Interesting from the site your shared: "The only potential drawback to a J-Hook rotor is that the passing of the J-Hook design through the pad can cause a light whirring sound that some customers might find to add character to the vehicle and braking system while some customers might find to be a bit distracting."

[0000 RS5]

I have had many drilled, slotted, and combo rotors over the years on numerous cars. The j-hook whir is definitely unique and fairly noticeable. I have APRacing front and 034 rear. I love them, i think the noise is cool. But no doubt about it, they do make some noise.


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[brobst]

Thank you for telling me what that buzzing sound is. I knew it was the rotor

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[S3DUDE]

I have Neuspeed 2 piece rotors with Carbotech pads and my car also makes a buzzing noise.

[Jeff_Jeske]

If you are running the DS2500 for a lapping day it's probably not the right choice of pad. Going with something more aggressive like the DS1.11 will shorten the amount of time you need to be on the brakes and actually reduce heat. I run the 2500s for my daily pad. The 1.11 is a nice jump up in stopping power but they are noisy. You should share pics of the rotors now that you have put some laps on them. The J-hook tends to show unique heat bands after a track day so don't be surprised if you see that.

As for the noise ... pretty much all slotted, drilled or hooked rotors will have that. Some people notice it others don't. I'm hesitant to tell people to test by driving next to a barrier as once you hear it you can't un-hear it ha ha. To me the J-hooks sound no different to any other performance two piece rotor I've had.

[Cool_Breeze]

If you are running the DS2500 for a lapping day it's probably not the right choice of pad. Going with something more aggressive like the DS1.11 will shorten the amount of time you need to be on the brakes and actually reduce heat. I run the 2500s for my daily pad. The 1.11 is a nice jump up in stopping power but they are noisy. You should share pics of the rotors now that you have put some laps on them. The J-hook tends to show unique heat bands after a track day so don't be surprised if you see that.

As for the noise ... pretty much all slotted, drilled or hooked rotors will have that. Some people notice it others don't. I'm hesitant to tell people to test by driving next to a barrier as once you hear it you can't un-hear it ha ha. To me the J-hooks sound no different to any other performance two piece rotor I've had.

Good point on the pads Jeff. Per my post update, I'll go with XP12s to reduce braking duration. Had a nice long chat w/Pete @ 529 innovations today :)

[Cool_Breeze]

Sure nice that you shared that insight. You going to put the matching rear on next ?

My front OEM rotors have made faint ticking noise after I put 2k miles on the car and now I’m at 17k. Two dealers told me the noise was normal and gave me the degassing explanation. I don’t track the car and I’m itching to replace all four rotor & pads even though they look fine.

I'm still on the original stock rotors and they've shown little wear so far. The pads are the original OEM set at 5mm. I'll likely run Carbotech 1521s in the rear to gain a little more bite, but not sure if upgrading the rear rotors will prove useful. Let's see how the temps look when I move to R-compound tires...

[Jeff_Jeske]

You should go buy a lottery ticket if you were lucky enough to have 034 are replace those rings for you!

Depending on the track, driver, car and vehicle management some rotors will only last a weekend.

I'd consider getting 50 punishing laps out of those pretty good.

[Cool_Breeze]

Another update!

The set of 034 rotors provided back in Oct just cracked after 5 track days, with a few spirited canyon runs in between. They were showing normal stress cracks after day 4, then after Sonoma last week, we found 5 large cracks on the right and 4 on the left. The 034 team says this is normal based on my setup, which includes Carbotech XP12s for track and 1521s for street. The 034 rotors performed well until the end, I just wish they'd last a bit longer. I'll attempt the Girodiscs to see if they hold up any better (thanks Pete @ 529innovations). 🤞🏼🙏🏼

[0000 RS5]

Why not go with AP Racing?


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[arulrs3]

Another update!

The set of 034 rotors provided back in Oct just cracked after 5 track days, with a few spirited canyon runs in between. They were showing normal stress cracks after day 4, then after Sonoma last week, we found 5 large cracks on the right and 4 on the left. The 034 team says this is normal based on my setup, which includes Carbotech XP12s for track and 1521s for street. The 034 rotors performed well until the end, I just wish they'd last a bit longer. I'll attempt the Girodiscs to see if they hold up any better (thanks Pete @ 529innovations). 🤞🏼🙏🏼

oh crap.. I'm running Girodisc front and I like those. For me it's 8-10 tracks days at VIR.

[TToysRuS]

Is this the J hook noise folks are referring to (I have AP/Essex J Hook Rotors on OEM pads) or is this the OEM pad rattle issue, or something else in your opinion? Definitely tied to the brakes, comes and goes and changes pitch when you press the brakes.

https://www.youtube.com/shorts/OYBUBOU9oys

[0000 RS5]

Is this the J hook noise folks are referring to (I have AP/Essex J Hook Rotors on OEM pads) or is this the OEM pad rattle issue, or something else in your opinion? Definitely tied to the brakes, comes and goes and changes pitch when you press the brakes.

https://www.youtube.com/shorts/OYBUBOU9oys

Yes, it is


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[TToysRuS]

Yes, it is


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J Hook noise you mean or pad rattle? Sorry just checking.

[ketchupfreak]

LOL shit. I thought the OEM cross drilled clicking was annoying. Sounds like a bird flying off every time you brake.

[0000 RS5]

J Hook noise you mean or pad rattle? Sorry just checking.

Yes, it is the j hook noise. And just like the factory rotors it is Lou see when you are next to something that reflects the sound back at the car. You can call me strange, but I like it. It sounds unique.


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[TheContrarian]

Thanks for reminding me about the bottomless money pit that is road racing. What's the true cost of a day at the track including all wear items + fees + fuel?

[0000 RS5]

Thanks for reminding me about the bottomless money pit that is road racing. What's the true cost of a day at the track including all wear items + fees + fuel?

Priceless


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[Cool_Breeze]

Priceless


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[Cool_Breeze]

Why not go with AP Racing?


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Girodiscs seem to be a better cost to value ratio…


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[TToysRuS]

Girodiscs seem to be a better cost to value ratio…


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I went with the AP racing as they were the lightest overall. I may go Giro when/if these wear out during their "tenure" on the car if they are quieter. The AP discs are very high quality though.

[Cool_Breeze]

I went with the AP racing as they were the lightest overall. I may go Giro when/if these wear out during their "tenure" on the car if they are quieter. The AP discs are very high quality though.

They came in today, install tomorrow! If they last 10 track days they’re keepers.


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[TToysRuS]

They came in today, install tomorrow! If they last 10 track days they’re keepers.


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Let us know if they make the noises that mine do if you dont mind?

[SimplyRS]

Let us know if they make the noises that mine do if you dont mind?

I’m only ~500 miles into my set but no noises on braking. Actually solved a clicking noise the oem brakes made at low speed lock turns


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[TToysRuS]

I’m only ~500 miles into my set but no noises on braking. Actually solved a clicking noise the oem brakes made at low speed lock turns


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Which rotors? 034?

[Chris F]

AP rotors with DS2500 have been super solid for me as a street setup would strongly recommend.

In addition to great stopping power/pedal feel/unsprung weight loss they have almost no noise (only tiny squeak at low speed when really cold/wet) and still work great in the worst snow/slush/salt/cold/grit Canadian winter can throw at them.

[TToysRuS]

AP rotors with DS2500 have been super solid for me as a street setup would strongly recommend.

In addition to great stopping power/pedal feel/unsprung weight loss they have almost no noise (only tiny squeak at low speed when really cold/wet) and still work great in the worst snow/slush/salt/cold/grit Canadian winter can throw at them.

My AP rotors are making the chuffing noise noted in the video i provided. I'm starting to think its pad rattle, not the rotors

[SimplyRS]

Which rotors? 034?

Yep 034 rotors 1521 pads


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[Cool_Breeze]

Update: I'm still on the same Girodisc rotors after 9 track days! They've held up quite well, and showing expected wear. This weekend I'm headed to Buttonwillow, and switching from Carbotech XP12 to XP10s in front. Let's see if they make it through the weekend.

r

[steve trac]

Just found this thread searching for j-hook rotor noise AFTER I put them in my S6 and I HATE it. Sounds like continuously pulling a zip tie. Very noticeable until you apply the brake. I had slotted Stoptechs for YEARS and don’t ever remember a noise that I hated like this.

Buyer beware. Had I known about it, I never would have bought them.

[Pandemic]

Update: I'm still on the same Girodisc rotors after 9 track days! They've held up quite well, and showing expected wear. This weekend I'm headed to Buttonwillow, and switching from Carbotech XP12 to XP10s in front. Let's see if they make it through the weekend.

r

checking in again, are the girodisc lasting longer than 034?

[Cool_Breeze]

checking in again, are the girodisc lasting longer than 034?

Yes, they've been rock solid! 10 track days (plus daily and canyons all year) on the current set and still holding up just fine. I would have gotten closer to 20 on my last set, but I wore the pads to the backing plate and scored the rotors

[Pandemic]

I'm sold, getting some