Will Brembos fit inside the 17" wheel?
I know they don't fit inside the 'spare'.

 

I’ve not actually attempted to fit a 17” rim over a set of Brembo rotors and calipers. I have read in the Cobalt site some have installed 17” rims for winter tires on their SS with Brembos.

I would contact ZZP and ask if they will infact fit.

 

I tried some 17’s and they easily cleared the Brembos on the diameter. It was the spokes that were the problem. I didn’t attempt to measure by how much.

Apparently one way others have dealt with Brembo clearance issues is with spacers. Just talked to a guy who got 18” pre-2008 Cobalt SS “LSJ” wheels to work that way.

Tire rack lets you select HHR SS and then “performance package” and then lists a nice choice of wheels that they say will fit, but they are all 18” or 19”.

 

Thanks, that’s what I thought! Spacers , not on my HHR! Just don’t like the idea of extra load in the front hubs!

 

Yeah, I feel the same way, at least about adaptors and thick adaptors. Radical offset reductions might look kool but raise safety issues. Added unsprung weight, too.

The effect of a thin spacer is probably trivial, and could conceivably improve bearing loading, depending on original geometry.

Anyway, adding a 5mm spacer (prolly ok w/o longer bolts) to a 42mm stock offset wheel would be exactly the same offset reduction as using a 37mm offset wheel, and 30 mm offset aftermarket wheels are used all the time. 18x8 seems to be pretty common. The stock 6.5 or 7.5” wheel width aren’t always acceptable for some of the wider tires.

 

The SS gets a 3mm spacer between the steering knuckles and hubs, maybe that’s what required to clear the 17” rims , or 6 mm spacers to clear the calipers
from the ZZP site

This is a complete kit with everything needed to install "LNF" Brembo brakes on your LSJ. The kit comes with a special wheel bearing spacer to correct the rotor to caliper spacing because of the difference in spindles. The factory LSJ rotor is 11.5" in diameter. This will also work as an upgrade on non Brembo LNF cars as well.

Includes:

(2) 12.25" Cross drilled and slotted rotors
(2) Brembo calipers
Banjo bolts and Copper washers
(2) Wheel bearing spacers
PowerStop brake pads
Stainless brake lines are not required, but we highly recommend them.

Make sure to verify the clearance between the caliper and the backside of the wheel. Some applications require wheel spacers. LSJ Cobalts will need a 5mm spacer to clear stock wheels, LSJ Ions will clear with no spacer. Fits LNF Cobalt wheels with no spacer as well.

Fits Cobalt, Ion, and HHR.
So, the 3 mm spacer is meant to line up the rotor to the Brembo calipers
And the 5 mm spacer between the wheel and hubs to clear the calipers.
Like the 87 Z28’s they had spacers for the front wheels to clear the calipers