[Bumbleboy92]

Please let me know if there is an issue. I took these numbers from Chevy's press releases and measurements from RockAuto.

I updated the chart with the confusing 12.6" / 321x30 compatible Brembos. From my understanding, LT 1LE cars received 4-Piston Brembos as a part of the 1LE package but they were smaller than SS Brembos and fit the LT 12.6" / 321x30 rotor instead. I'm unsure if the late model LT 1LE cars followed suit or switched to the SS 4-Piston Brembo but this was when the 1LE package was released. I can attest to this as I have 12.6" OEM on my 2016 1LT and have 4-Piston Brembos that fit. Plus the part number for a LT 1LE rotor is 1771158 and the RockAuto specs list 12.6" / 321x30mm - Edit: I doubt they changed them since the LT1 is using the same size. Most likely the LT 1LE trims have been using 12.6" / 321x30mm since 2017 and the LT1 inherited them

For LT1, both PowerStop and RockAuto list 12.6" / 321x30mm as the only size for LT1 front rotors.

RIP factory optioning 6-Piston Brembo's on LT cars

Added the copper free rotor info

Added 5LQ information and some more brake options from packages

[arpad_m]

Beautiful summary, thanks for the post

[SS_Don]

Nice chart. What year(s) is it for?

[Bumbleboy92]

Originally Posted by arpad_m

Beautiful summary, thanks for the post

Originally Posted by SS_Don

Nice chart. What year(s) is it for?

Thanks!

2016 to current should be, I got the sizes off Chevy press releases then followed up with the thickness from RockAuto since RockAuto listed all rotors regardless of trim.

[The Maverick]

The 4-piston Brembos on the LT#'s were also part of RPO Y4Q, the Heavy-Duty Cooling and Braking Package. That option was dropped toward the end of the 2021 model year due to the copper brake pad issue with CA/WA. I snuck in just under the wire with my DEC 2020 manufactured 3LT.

An additional trivia note: Out of the 1,048 3LT's built during the 2021 model year, 196 included the Y4Q package.

Originally Posted by Bumbleboy92

Updated the chart with the confusing 12.6" / 321x30 compatible Brembos. From my understanding, LT 1LE cars received 4-Piston Brembos as a part of the 1LE package but they were smaller than SS Brembos and fit the LT 12.6" / 321x30 rotor instead. I'm unsure if the late model LT 1LE cars followed suit or switched to the SS 4-Piston Brembo but this was when the 1LE package was released. I can attest to this as I have 12.6" OEM on my 2016 1LT and have 4-Piston Brembos that fit. Plus the part number for a LT 1LE rotor is 1771158 and the RockAuto specs list 12.6" / 321x30mm - Edit: I doubt they changed them since the LT1 is using the same size. Most likely the LT 1LE trims have been using 12.6" / 321x30 since 2017 and the LT1 inherited them

Next time I have a front wheel off I can take a measurement to confirm what was used for the Y4Q package in 2021 (same RPO as came with the 1LE/A1X, I believe) , but I think your conclusion that these remained the same is correct.

[Bumbleboy92]

Originally Posted by The Maverick

The 4-piston Brembos on the LT#'s were also part of RPO Y4Q, the Heavy-Duty Cooling and Braking Package. That option was dropped toward the end of the 2021 model year due to the copper brake pad issue with CA/WA. I snuck in just under the wire with my DEC 2020 manufactured 3LT.

An additional trivia note: Out of the 1,048 3LT's built during the 2021 model year, 196 included the Y4Q package.


Next time I have a front wheel off I can take a measurement to confirm what was used for the Y4Q package in 2021 (same RPO as came with the 1LE/A1X, I believe) , but I think your conclusion that these remained the same is correct.

I'm pretty sure the 4-Piston Brembos are still in production for LT cars, I see the Y4Q option in the current order guide, and on the Camaro builder online it makes you also add the RS package or 20" wheels to receive the 4-Piston Brembos alone. You can also select the Heavy-Duty Cooling and Brake Package separately which includes it but has the same constraint of RS package or 20" wheels. (See below)



Though the 6-Piston Brembo was removed as an option starting in 2023 for the LT trims.



That's the 2021 - 2022 - 2023 Camaro order guides, 5LQ is the 6-Piston Brembo upgrade and they removed the option from non-SS cars in the 2023 model. If anything, I'm at least glad they didn't remove the 4-Piston option since they've already phased out the 1LE and 6-Piston options for LTs.

[The Maverick]

Originally Posted by Bumbleboy92

I'm pretty sure the 4-Piston Brembos are still in production for LT cars, I see the Y4Q option in the current order guide, and on the Camaro builder online it makes you also add the RS package or 20" wheels to receive the 4-Piston Brembos alone. You can also select the Heavy-Duty Cooling and Brake Package separately which includes it but has the same constraint of RS package or 20" wheels. (See below)

That's good to hear - I must have misremembered some of the details of the copper-free brakes boondoggle!

Although, looking at the NHTSA posting of the GM service bulletin on the copper brakes, it says there was no copper-free option for the Y4Q option package in model years 2021 and 2022 (see text on right half of page 2 and table at the bottom of page 3). So maybe rather than being discontinued, what news reports I was thinking of were "sorry buyers in CA and WA" and wherever brake pads including copper aren't permitted?

https://static.nhtsa.gov/odi/tsbs/20...ukwcEMWnJdKup3

And I just noticed the order guides you posted above indicate just that - not available in CA or WA. They originally looked microscopic on my phone but I was able to get them to zoom to a legible size.

[Sillysspeed]

Thanks for that chart. Now just wondering is there a 2-pc rotor available for the lt-1le and lt1 cars?

[Bumbleboy92]

Originally Posted by The Maverick

That's good to hear - I must have misremembered some of the details of the copper-free brakes boondoggle!

Although, looking at the NHTSA posting of the GM service bulletin on the copper brakes, it says there was no copper-free option for the Y4Q option package in model years 2021 and 2022 (see text on right half of page 2 and table at the bottom of page 3). So maybe rather than being discontinued, what news reports I was thinking of were "sorry buyers in CA and WA" and wherever brake pads including copper aren't permitted?

https://static.nhtsa.gov/odi/tsbs/20...ukwcEMWnJdKup3

And I just noticed the order guides you posted above indicate just that - not available in CA or WA. They originally looked microscopic on my phone but I was able to get them to zoom to a legible size.

I'll try to incorporate that into the chart!

Originally Posted by Sillysspeed

Thanks for that chart. Now just wondering is there a 2-pc rotor available for the lt-1le and lt1 cars?

I'm sure there are aftermarket rotors that will fit, I don't believe GM sells any OEM ones in the size. Though you should be able to upgrade your calipers and rotors to any of the OEM sizes listed without issue, would have to get the accompanying accessories (lines, bolts, etc.). The only restriction would be if you are running smaller wheels than OEM or aftermarket wheels for clearing the caliper

[Sillysspeed]

Originally Posted by Bumbleboy92

I'll try to incorporate that into the chart!



I'm sure there are aftermarket rotors that will fit, I don't believe GM sells any OEM ones in the size. Though you should be able to upgrade your calipers and rotors to any of the OEM sizes listed without issue, would have to get the accompanying accessories (lines, bolts, etc.). The only restriction would be if you are running smaller wheels than OEM or aftermarket wheels for clearing the caliper

I’d like to keep the stock size rotors since I run 17’s up front at the track. Just wanted the lighter weight

[The Maverick]

Originally Posted by Bumbleboy92

I'll try to incorporate that into the chart!

Looks good! To nail down the CA/WA issue, you might want to add "after December 2020" to the "not available" notes on the chart.

[FJ4dan]

Trying to add brembro's to 2019 1LT without using SS rotors and thought this might be a good tread to ask. Like to keep it "stock" and lower cost. Wife is getting a bit tired of the camaro bills haha.

1. Have the GM 84636644 and 84636645 in the cart at rock auto for $400 total. just want to be sure they fit the 12.6 rotors?

2. Pads?

3. Are bolts different?

4. Lines different?

5. If I want to track if for fun a few times a year should I skip and get the SS setup with larger rotors or would I even notice the difference?

did a search here for brembros and came up empty. Is there a thread on this I missed.

Thanks so much for the help! Just got a 19 and super excited to improve it.

[Bumbleboy92]

Originally Posted by FJ4dan

Trying to add brembro's to 2019 1LT without using SS rotors and thought this might be a good tread to ask. Like to keep it "stock" and lower cost. Wife is getting a bit tired of the camaro bills haha.

1. Have the GM 84636644 and 84636645 in the cart at rock auto for $400 total. just want to be sure they fit the 12.6 rotors?

2. Pads?

3. Are bolts different?

4. Lines different?

5. If I want to track if for fun a few times a year should I skip and get the SS setup with larger rotors or would I even notice the difference?

did a search here for brembros and came up empty. Is there a thread on this I missed.

Thanks so much for the help! Just got a 19 and super excited to improve it.

I don’t know about the PN but,

Pads you’ll have to buy since the OEM is a single piston and the Brembo is 4 Piston so you’ll have to buy the corresponding pads.

I believe the bolts can be reused from your original calipers but not entirely sure.

Lines I can’t speak on either unfortunately, when I swapped I had bought a pair of SS goodridge lines.

Imo, you won’t see a noticeable difference between 12.6” and 13.6” rotors for the LT vehicles. Same reason why LT’s don’t have the extra cooling like the SS

[FJ4dan]

Originally Posted by Bumbleboy92

I don’t know about the PN but,

Pads you’ll have to buy since the OEM is a single piston and the Brembo is 4 Piston so you’ll have to buy the corresponding pads.

I believe the bolts can be reused from your original calipers but not entirely sure.

Lines I can’t speak on either unfortunately, when I swapped I had bought a pair of SS goodridge lines.

Imo, you won’t see a noticeable difference between 12.6” and 13.6” rotors for the LT vehicles. Same reason why LT’s don’t have the extra cooling like the SS imo

thanks bubbleboy!

keep it simple sounds good.