Here is the size difference between the 2 rotors.

https://www.chevyhhr.net/gallery/fil...0714121532.jpg

bump

Brake upgrade
 

I just bought a Cobalt SS rear axle off of a guy on the Cobalt SS website. Very reasonable. I am having it sandblasted and installing new hoses, rotors and pads. I also bought new parking brake cables. ABS is the same wiring on the 2005 Cobalt SS and I am reusing my rear hubs.
I also am buying Brembo front rotors, calipers and pads from the same guy and have hoses and spacers on order. I will try to do a "How to" with photos to document it.
I am also installing a Cobalt supercharger over the winter. That should be fun.

Awsome PLEASE DO a complete How To with LOT O PICS! :cool: :thumb:

Do you have ABS and Traction Control ?

Sweet, its a good setup, the parking brake cables are a must for pedal feel and very easy to install, just a heads up with the front Brembos, I used wheel spacers from (summit racing only like 18 bucks shipped) to clear the inside of the wheel and the caliper, It looks like you have diffrent wheels then mine, (stock 06 2lt 17 in for mine) so I do not know if it matters but they did the job for me.

Brake update
 

My "SS" wheels will pose no problem with clearance as SS HHRs came with Brembos as an option. The spacers I bought came from GM and take the place of the dust shield(backing plate) behind the rotors. I almost have all parts together to do the brake update. I will try to remember to document all of it with pictures.

:cool:


:twothumbs:





:skull:

https://www.chevyhhr.net/gallery/fil...0831121322.jpg
rear disc
https://www.chevyhhr.net/gallery/fil...831121322a.jpg
parking brake cable

https://www.chevyhhr.net/gallery/fil...831121322b.jpg
bolt holding the rear axle beam

sorry if pics are bad, not the best photographer

Brake conversion
 

Well.....I finally did my brake upgrades. Same as Pbatmen. Brembos up front and Cobalt SS rear axle. I tried to remember to take lots of pictures, but probably not as many as I should have.
The front was ridiculously simple. Unbolt the old caliper and set aside with hose attached. slip off rotor and replace with Brembo rotor. Install Brembo caliper with two bolts mounted to old caliper bracket mount position and remove and install brake hose(I used brand new GM ones and they came with the brackets and retainer bolt with copper washers. I did not use the spacers that are shown. They SS steering knuckle and hub and bearing assembly must be slightly larger than the 2LT one. I then gravity bled the system and the job was done. Then I started the rear.

Rear disc brakes
 

Now for the rear.
I purchased the rear axle from a guy on the Cobalt SS site. He is also the same guy that I purchased the Brembo calipers and rotors from. He may have more available if anyone is interested. Mongorat is his call name. He is very reasonable with pricing and has quite a following. I also bought my supercharger package from him.