I just wanted to share my plans for the GXP this winter. I don't drive it during the Michigan Winters, so its the perfect time to do everything I've been wanting.
I recently did my whole suspension, with new Bilstein HD struts, SSC Lowering Springs, CV Axles, Hubs etc. Back when I did brakes, I got shitty Rotors from AutoZone and they rusted after my first car wash.
As you can see, the suspension looks beautiful, minus the crappy Rotors:



My original plan was to do the CTS-V swap, so I ordered the Calipers.
Then I got to thinking that I didn't want to add the extra 4lbs of unsprung Rotor weight. (actually more, because the calipers themselves are 2lbs a piece, so 8lbs total)
I already run GT500 Wheels during the summer, so I am adding rotational mass there; I don't want to add on to that any more.
So I retracted my original plan and ordered 12.7 Raybestos Rotors as stock replacements, and I was going to clean up the caliper brackets to make the GXP brakes look better.
(Add new rubber guide pin covers, paint the caliper bracket black, etc).

Well, I received the Brembos in the mail today, and may have had a change of heart:



So basically, I have new hardware and Rotors for the stock GXP Brakes in the mail on the way... And I have Brembos sitting on my table now.
One of those items will be returned because they won't work with eachother, but I can't make a decision.
With the CTS-V package, I would be theoretically adding 80 lbs to the car. I don't want to make it out like I'm chasing 1/10ths.... But I'm kind of chasing 1/10ths. Sooner or later these things cause you to lose the advantage to cars on the street that you would normally run door-to-door with.

Anyone want to offer their input??

 

116 views and nothing.
Either we have a bunch of people with stock LS4 cars that know absolutely nothing or... no that's probably it (excluding 91parkave, GXP25 and a few others)

This site sucks for this platform. See ya at Grandprixforums!

 

Haha wtf. Car looks good man. How hard was it to get those 19s to fit?

 

Use the CTS-V calipers and get some stainless brake lines~!!

 

Done .

The net weight gain will only be 2 lbs per rotor so 4lbs all together. Won't even notice the difference.

 

Not hard at all. Just got them mounted and balanced, and threw them on.
I spent about 3 solid weeks researching the fitment and weight before I bought them though. I also bought 1, and did a test fit before buying the remaining 3.

I wanted to make sure that I wasn't gaining a lot of unnecessary weight.
The wheels themselves are 29 lbs, and the tires are 22lbs. That equals 51 lbs, the weight of stock 8" Alcoas and tires.

However, the rear Alcoas and wheels weigh 47lbs, so I am gaining a total of 8lbs in the rear. Totally worth it though, my fitment is flush, and I get compliments all the time.

My tires are 22lbs each. Good luck finding a 255 that is lighter than that.

 

Make sure you swap the bleeders and cross over pipes on those CTS-V calipers. And get them powdercoated.

If you need a "GXP" decal, let me know. After you powdercoat them and apply the decal, spray them with some Dupli-Color engine enamel with ceramic clear coat. You can get it on amazon. It's good for up to 500°F.

 

how much of an improvement is that? i figured the brakes were one of the things they got right on these cars lol

 

Cross over pipes should be down and bleeders should be on top correct?

 

I'll let you know fairly soon. I'm sure it will be pretty noticeable.

 

can you tell a difference with the shocks and springs?
that might be a winder project for me.

 

It's not that simple. That's done that way so that it's easier to bleed them; air rises.

The calipers that you bought are side-specific; the pistons are of different sizes.

The left CTS-V caliper is the left (driver) side for a reason. When you mount it on the left side of your vehicle, you'll notice that the bleeders face downward and the crossover pipe is in the air. So instead of swapping the entire caliper assembly side-to-side, you'll want to swap the bleeders and crossover pipe from the right side caliper. The STS-V is setup this way. If you bought those calipers you wouldn't have to worry.

 

Gotcha. So then the bleeders and crossover pipes from the left side caliper goes on the right?

 

Do what you want with the bleeders.

 

Thanks, then I can just flip the bleeders to the other side.

 

GXP25: One more question.
The Brakes I bought didn't come with the pins and brake pad bracket.
Are these the correct parts to complete the caliper?:

 

Those don't look right.

Oddly enough, if you purchase pads from the auto parts store, their high end pads will come with the pin kit.

Here's the one you want: 89047711 (18K1971X).

You only need one kit for the front since each kit comes with two sets (one per caliper). Get it from Amazon.

 

Thanks, I noticed that too, but I wasn't sure. The picture I posted has the slotted hole on the top, but from everything I've seen there are two circles.

Ordering right now!!

 

Went over to my Gpas, because I can spray in his basement. Better alternative than working on this **** in the cold.

Painting the Rear Calipers Silver to match the fronts:


Painted the Rear Caliper Bracked black. Also have new hardware:


New guide bolt boots and pad brackets:


Painted that annoying Gold Radar Detector piece:


My GT500 Wheels sleeping:


I also weighed my Stock Front Calipers and the Caliper Brackets... 10 lbs even. Weighed the CTS-V Calipers.. A hair under 8.5 lbs. I still need to weigh the Rotors, (and the pads, which I assume will be a push) but if the figure I have seen is correct for the GT500 Rotors (2lbs heavier), I will actually only gain .5 lbs of unsprung weight per wheel.

 

When I was grasping for ever 1/100th I could with the camaro I never shyed away from extra weight if it improved safety or performance.

My philosophy was to gain it back with horsepower. I literally had one of the worst drivetrains as far as weight goes but I still dynoed over 700rwhp and ran high 9's and never once worried about cutting my day short due to broken drivetrain parts.