DIY Big Brake Kit with Brembo 6 piston Calipers

[vietfella]

takes about 60 seconds with a cutting wheel. make one slit, then use pliers to fold the cut over and it will pop right off.

had to make two cuts for mine but mimiced the older tesla version of the dust shield

 

[Lindenwood]

Guys, I got correct part numbers for the calipers here. I referenced ZZPerformance, Racing Brake, GM's site, and various LS1, CTS, Corvette, S14, GTR, etc forums to gather this info. I hope there are no typos here.

Gen 2 CTS-V 6 Piston
Yellow:
GM P/N 20982719 or AC Delco P/N 172-2521
GM P/N 20982734 or AC Delco P/N 172-2522

Silver:
GM P/N 25912477 or AC Delco P/N 172-2487
GM P/N 25912967 or AC Delco P/N 172-2488

Red:
GM P/N 22885106 or AC Delco P/N 172-2595
GM P/N 22885108 or AC Delco P/N 172-2596

ATS-V
Gold:
GM P/N 23121834 or AC Delco P/N 172-2685
GM P/N 23121835 or AC Delco P/N 172-2686

Red:
GM P/N 23121832 or AC Delco P/N 172-2683
GM P/N 23121833 or AC Delco P/N 172-2684

Silver:
GM P/N 23121830 or AC Delco P/N 172-2681
GM P/N 23121831 or AC Delco P/N 172-2682

Camaro 6G SS 1LE 6 Piston
Red:
GM P/N 84063672 or AC Delco P/N 172-2741
GM P/N 84063673 or AC Delco P/N 172-2742

Camaro 5G ZL1
Black:
GM P/N 20944530 or AC Delco P/N 172-2537
GM P/N 20944518 or AC Delco P/N 172-2538

2015-2019 Corvette Z06 - has dimpled pistons for supposedly better cooling
Red:
GM P/N 23242497 or AC Delco P/N 172-2669
GM P/N 23242498 or AC Delco P/N 172-2670

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Caliper bolts from the CTS-V are M14 x 2 and 56mm long. Stock M3 caliper bolts are M12 x 1.75 and 45mm long. So... You'll have to either:

1. Easiest method. Drill out the pilot holes with a 14mm or 9/16" drill bit. Then, purchase the GM 56mm long M14 x 2 bolt and use washers to eat up approximately 12mm of the bolt to prevent it from protruding too far. GM also has 45mm long M14 x 2 bolts made for the Camaro, or eBay has them available as well. If you do this and ever decide to go back to stock, then you just need to shim the widened pilot holes with a 14mm OD 1mm thick aluminum pipe cut into a shim (ID = 12mm to fit the stock caliper bolt). Amazon sells the aluminum pipe for $10.

2. Keep things stock method. Get the caliper threads tapped with a 24mm long M12 x 1.75 time-sert. These are hardened steel threads that are commonly used to repair stripped aluminum threads in engine blocks and such. Rethreading the calipers to fit M12 x 1.75 bolts should be easy. You find a machine shop or auto shop to tap the existing calipers with the time-sert insert, and that's it. You can buy the time-sert kit and do it yourself as well. It's about $120 for the kit, and $25 for the 24mm long inserts. Many places to buy time-sert kits. Just be aware that you have to cut new threads into the calipers if you go this route.

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Brake pads. Stock Brembo pads are P/N 171-1040, and at this time are about $225. I hear they're decent, but a little dusty. My research in other forums revealed users tracking them with good results, but they'll wear out quickly. Otherwise, just grab your preferred street or track pad made for these GM calipers (which will likely match many other 6 pot Brembos, but I have not confirmed that).

You will need to purchase the pad pin kit for the above calipers P/N 18K2108X

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Rotors. This is where we are today with the Girodisc group buy. Hopefully, they pull through with the currently committed people. That way we can simply purchase off the shelf parts from them. 370mm x 34mm rotor rings for the CTS-V, Corvette, Camaro are already available through Girodisc, so having the hats made is the last step.

Alternatively, you can buy the Racing Brakes kit that includes all you need to install this BBK except the calipers (see above for your choice of color and logo). RB BBK (370x34) for Tesla M3 Retrofit to Cadillac CTSV V2 or Camaro G5 ZL1 6 Pot Calipers
Many of us much prefer to go with Girodisc, though.

Lastly, as someone already did for the previous gen Model S, you can design your own hat and mate it to the correct Brembo rotor ring. You simply need to have access to your own machine shop and design studio to do this. DIY...Big Brake Kit for Under 2k

Seriously, this was tremendously helpful!

 

[drpheta]

No problem. If I'm doing the research anyway, why not share the info? Happy to help

I was all set to get these installed today, but I hit a snag. My 14mm drill bit I bought online didn't have a reduced shank, so it didn't fit in my drill. I don't know why I didn't bother to test it out before this weekend. Grrrr.

I was almost at the finish line and had to put the old calipers back on until I get my new 14mm reduced shank drill bit comes. At least I got the dust shields cut off. Good thing I didn't disconnect the calipers off the brake lines yet and didn't have to unnecessarily bleed the lines.

 

[Motion122]

Thank you for the great data!

I have been reading through some brake pad threads on the Camaro forums and several are also reporting the Power Stop Track Day Pads, PST 1405, are a pretty decent pad for a DD seeing occasional track days. Specifically, they don’t seem to wear quite as long as other dedicated pads (order of magnitude 50-65% as much track time), and sound like they dust more than most, but generally hold up to the heat and can be had for around $150 per front pair.

Lots of positive reports on the ST-43s, though.

With this caliper doors are open for great hybrid pads like the Ferodo DS2500 and their endurance track day pad DS1.11.

 

[vietfella]

No problem. If I'm doing the research anyway, why not share the info? Happy to help

I was all set to get these installed today, but I hit a snag. My 14mm drill bit I bought online didn't have a reduced shank, so it didn't fit in my drill. I don't know why I didn't bother to test it out before this weekend. Grrrr.

I was almost at the finish line and had to put the old calipers back on until I get my new 14mm reduced shank drill bit comes. At least I got the dust shields cut off. Good thing I didn't disconnect the calipers off the brake lines yet and didn't have to unnecessarily bleed the lines.

I had the same issue, I ended up buying a new drill with 1/2" shank since the standard drills are 3/8" shank.

 

[Motion122]

I know there are some aftermarket wheels that are 18" and will clear larger brakes than these

My wheel setup is 19x9.5 +30 on Aspira AF-10 on Hankook S1 Ventus Evo2 265/35/19
Aspira AF-10

It's usually the caliper shape that is the issue(Brembos run big). Stoptech 380 ST/STR-60 often clears most 18" aftermarket wheels with caliper clearance in mind in the design phase.

 

[Lindenwood]

Now that folks are getting these in their hands, how much thicker are the rotor hats? Do they eliminate the ~3mm hub step?

I just realized I specified the offset of my new 19x9.5s relative to my current setup (20x9 +18 up front with 255/35R20), but the offset will drop a hair with the new rotors.

I am not too worried about rubbing, given I’ll always be shimless (3+ degrees of camber) when running these wheels, plus the 275s are a hair smaller in diameter. Still, it will be good to be ready!

 

[jesse_le]

@Lindenwood - Girodisc rotor hat thickness is ~7mm. Stock Performance rotors are 3mm thick, so this will move your wheel out towards the fender by 4mm.

The Girodisc rotors were designed to eliminate the stepped hub issue.

 

[Bennny]

How does this compare to the MPP Stoptech package?

 

[Lindenwood]

This is all based on zero personal experience…

The MPP rotor is 368x35mm vs 370x34mm. MPP describes 32mm width as “not enough” for the most aggressive use, so perhaps there is some measurable difference between even 34mm and 35mm. They do assert no noticeable difference between their 368 and 380mm rotors, which is surprising.

I would expect their assertions that the calipers are very stiff for their weight to be true, though I wouldn’t know how to quantify that actual result from a performance perspective, or qualify the feel from a driver perspective.

MPP has $5500 of my money so I clearly like and value what they offer. That said, I would expect if there is a hierarchy of drivers who could truly appreciate brake upgrades, it is probably something like…

97%: No benefit moving past Bone Stock Performance brakes

2%: Really could just good pads and rotors (aggressive AutoX runs on 200tw tires, or light-to-moderate occasional track days).

0.8%: Would genuinely benefit from moving to this “budget” BBK setup

0.12%: Would appreciate the difference between this and the MPP kit

0.07%: Would appreciate the difference between the MPP kit and and the 394mm UP kit (which I can’t qualify beyond rotor diameter).

0.01%: Would appreciate the difference between the 394mm kit and the UP Carbon Ceramic setups .

 

[drpheta]

I'm more inclined to say that at the 365mm diameter with a 34mm thickness we've reached a threshold for braking performance that surpasses all available grip on tires sized for our car. Going up in thickness or diameter at this point likely results in minimal marginal improvement. Maybe even imperceptible or none at all.

I would imagine that at this point using carbon ceramic rotors is only beneficial for extremely aggressive braking, which is rare.

 

[Lindenwood]

I'm more inclined to say that at the 365mm diameter with a 34mm thickness we've reached a threshold for braking performance that surpasses all available grip on tires sized for our car. Going up in thickness or diameter at this point likely results in minimal marginal improvement. Maybe even imperceptible or none at all.

I would imagine that at this point using carbon ceramic rotors is only beneficial for extremely aggressive braking, which is rare.

As I understand it, bigger only gives you more stops rather than harder stops. As an example, if the rotor walls are maybe 5mm thick, the difference in internal air volume (and thus the output) between 34mm and 35mm width is about 4%, which is arguably not nothing. On a similar note, going from 370 to 394mm does result in not only about 15% more rotor area for heat absorption and radiation, but also about 6% more torque on the rotors which means 6% less heat put into them.

 

[drpheta]

As I understand it, bigger only gives you more stops rather than harder stops. As an example, if the rotor walls are maybe 5mm thick, the difference in internal air volume (and thus the output) between 34mm and 35mm width is about 4%, which is arguably not nothing. On a similar note, going from 370 to 394mm does result in not only about 15% more rotor area for heat absorption and radiation, but also about 6% more torque on the rotors which means 6% less heat put into them.

That's what I was alluding to with iron rotors. At that level the marginal benefit is very low or null given our tires' ability. Sure, the brakes can deal with better heat management, but the tires are going to get squirrelly.

After that, the next major jump in performance is to carbon ceramic, but again how are the tires faring? There is, however, a benefit from unsprung weight reduction. I could see this benefit handling and stress on the tires.

 

[drpheta]

Finished the front brakes. Kids kept bugging me to play with them, do I'll do the rears another day.

Rotors aren't that much larger than the stock M3P rotors, but they're thiiiiiccccc.

 

[Motion122]

Finished the front brakes. Kids kept bugging me to play with them, do I'll do the rears another day.

Rotors aren't that much larger than the stock M3P rotors, but they're thiiiiiccccc.

By any chance you weigh the caliper and rotor? Thanks!

 

[drpheta]

By any chance you weigh the caliper and rotor? Thanks!

I don't have a scale as I'm between houses right now. Most of my stuff is in storage. I managed to install these with my old emergency hand tools and some stuff bought at the local tool shop.

 

[3geekfamily]

Finished the front brakes. Kids kept bugging me to play with them, do I'll do the rears another day.

Rotors aren't that much larger than the stock M3P rotors, but they're thiiiiiccccc.

Well hey, new frisbee!

 

[jesse_le]

Nice work @drpheta !

 

[drpheta]

I didn't take a photo, but my MPP SS Brake lines are too short to mount the tab to the knuckle. So, I just zip tied it into itself to reduce the slack from catching a rotating part.

 

[Motion122]

I didn't take a photo, but my MPP SS Brake lines are too short to mount the tab to the knuckle. So, I just zip tied it into itself to reduce the slack from catching a rotating part.

Typically, with a different caliper you will also need a different line. On the Camaro I did the CTS-V BBK upgrade the SS line had to be upgraded.