Kracka

No, cast iron w/zinc coating to prevent rust on the hubs and vanes.

ArizonaZ06

No that was my bad on post #8 regarding the all aluminum Powerstop statement. A bit confusing.

The Gyrodisc 2-piece that I have on my C8 are. 1) Aluminum on the central hat section of the rotor is made from 6061-T6 aircraft specification aluminum.

2) The rotors are cast iron. Once the Gyrodisc system is in place you only replace the cast iron rotor when needed.

Sorry for the incorrect statement.

teddyca

NOTE I AM NON Z51!!!!
OK My lazy *** is getting this done today. I will update this post as I go with details of my journey.

-According to my fairly new scale, the front Powerstops are 19.6lb. I weighted both and they were the same. I also weighed myself and I am 175 exactly with rotor 194.8lb Thats 19.9lb so were close
-Rears come in at 17.4lb. same process with me 192.4lb is exact.
- Stock rear about 17.9lb
-Stock front about 21.1lb

Kracka

Awesome! Please weigh your factory rotors as well, and I'll do the same with mine (Z51).

Kracka

OEM Z51 rotors with 20k miles on them:
front - 24.6 lbs.
rear - 23.5 lbs.

According to @teddyca post above, the non-Z51 PowerStop rotors save 1.5 lbs/each up front and 0.5 lbs/each in the rear. That's a combined rotational savings of 4 pounds. That tells me the Z51 savings should be approximately 5 pounds total.
​​
(24.6+23.5)/(21.1+17.9)=1.2333
1.2333*4=4.93

teddyca

My numbers might be off a bit but not much. Scale is new but it would fluctuate about 2-4oz. Did I notice any difference. Nope. They look cool though which is why I ordered them. LOL Now once I slap those Vtec stickers I told you I am ordering, I should see 50hp.

Kracka

500-mile update
I know better, but I did it anyway... I installed new rotors reusing partially worn pads. Two weeks ago they randomly started squealing when cold. I figured ok, odd, but maybe they just need to be re-greased (I didn't clean or regrease then during the rotor install process and just left them loaded in the calipers). Last weekend I took the pads out, cleaned them, and re-greased them; no change, that wasn't it. I inspect the rotors a little closer and I see the pads aren't evenly contacting the friction rings. This makes sense as my factory rotors had some strange wear marks dating back to the factory pads, and my original set of Z26 pads clearly wore into those grooves and aren't contacting the new set of rotors uniformly!

I ordered a compete new set of Z26 pads from RockAuto Sunday, delivered Tuesday, and installed today. I completed the bed-in process this morning and perfection! Better overall feel and total silence! This time, I used PowerStop's included hardware since my factory pins/springs had been in & out multiple times already and I wanted to start completely fresh.

So, end of the day, lesson learned, j should have just done it right the first time, but that's on me for trying to save a few bucks (I'm actually more irritated at myself for the wasted time).

New pads on used rotors = YES
Used pads on new rotors = NO