50s cowboy

I searched all the parts to put larger rotors on my HHR and found all I needed was the ss caliper bracket to use larger 11.65" rotors. Now
all I need to do is clean up my calipers and paint them...

donbrew

But what do you accomplish without more braking surface? Just a little more heat dissipation, but no more stopping power. Some physicist (not me) might even be able to show a decrease is performance.

If the aim is to reduce rotor warp, that might help, but adjusting the rears does that too.

I'll bet the wear ridges will look odd.

I am not criticizing, just discussing.

whopper

Hummm............. thinking that with the pads being further out from the hub, the result will be:
- the pads/calipers will provide an increase in braking power (like more leverage/anti-torque in my humble technical vocabulary LOL)
- the swept area on the rotor will be larger with the bigger rotors - resulting in less heat as it also has a bigger area to dissipate the heat from.
- cool factor is increased. :-)

sleeper

Precisely..

donbrew

OK swept area is increased, but what about total friction area? Wouldn't that be proportionately decreased? Oh boy, science at 0130.

Verry interestink.

whopper

Lol - my brain is starting to hurt.

Proportionately decreased - yes. However, the total friction area remains constant (still has the LT pads), so the only benefit really comes from the increase in swept area.

........... I think............

LT1GMC

Braking power is increased by the leverage of the caliper being farther out with the larger rotor, just like sitting to the far end of a tetter-totter. You have increased swept area which contributes to better cooling, but the leverage is what really increases the braking power.
Just a note, the advantage of the Brembos is even more rotor diameter, but mostly 4 pistons pressing on the pads, much more pressure means more braking power. BTW, the Brembo pads are not much bigger than the stock pads, its that they have more hydraulic pressure pressing on them.

2005HHRauto

Yes, this will work, & is better than the HHR SS front brake setup...

Don't know what in the world That GM was thinking when designing the HHR brake systems...

When designing the HHR, I'm thinking that the engineers treated it as a 'truck', with hauling capabilitys, & it was listed as a 'truck', by GM.
The front rotors are heavy, Appox: 16 lbs, & aren't used on any other GM vehicles. The front calipers have a 60mm piston, & is a common caliper used with other GM vehicles.

After a few years, the HHR SS came along...
The front rotors are 3/4" bigger in diameter, at 11.65", & Appox: 1 lb heavier.
BUT, they also put on a strange caliper, with a smaller 54mm piston. This small piston caliper isn't used on but a few GM vehicles. Don't know why GM did this ??

So by going with the bigger SS rotor, with the stock HHR caliper, you'll have better , stronger braking, on your HHR LS or LT.

In fact, this same 'combo', is used on my factory stock 2004 Malibu Maxx, which also has the exact same rear discs, & calipers as my HHR SS.
And yes, my 2004 Malibu Maxx braking, feels better than my stock 2009 HHR SS brakes. Makes you wonder why GM does, what it does...

I did think that maybe the master cylinders were different, but they aren't.
The HHR LT , with stability control, master cylinder, is the same as used on the HHR SS.

I have done some testing:

https://www.chevyhhr.net/gallery/fil...px_329693.jpeg

I'm running a brake setup that works very well for me, for the 1/4 mile, & as a DD.
1996 Honda Accord 11.5 lb front rotors, & 2012 Honda Civic SI 7.5 Lb rear rotors.
I'm also using the standard HHR front calipers, with the bigger 60mm pistons.

donbrew

OK, got it.

2005HHRauto

Also, the HHR SS guys, can have harder 'hitting' braking, by going with the stock HHR front calipers, with the bigger 60mm pistons...

For the HHR LS/LT guys, when replacing your front rotors, go with a much lighter rotor from
The 2004 Malibu, [not the classic model], with 2.2 engine. You'll get better gas mileage, & better throttle response.
It's a direct bolt on, With a saving of at least 2lbs per rotor...


http://www.centricparts.com/
Everyone has their 'favorite' brake rotor/parts brand.
I have found that Centric is the 'bomb', with all their brake parts, for all cars/trucks.
I lookup what I need on their website, than usually buy from Amazon, as you can't beat
Amazons free shipping on rotors...

My wife is hard on rotors, & I couldn't find rotors that would last on her car, for more than 2 years. The Centric front rotors that are now on her car, are going on 4 years old, & still look/work like new...