Brake Speculation

Suspension, brake, and hydraulic/electric steering discussion.
CrashTestDummy
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Re: Brake Speculation

Post by CrashTestDummy »

About the only reason I can see for bigger brakes is fade protection, and sometimes modulation ease. The tires are going to be the deciding factor on how fast the car stops in most instances, but at higher speeds, and repeated stops from higher speeds, say at a track time trial, you'll want the added mass to absorb and move the heat away from the calipers.
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GTObert
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Re: Brake Speculation

Post by GTObert »

I'm doing it because:

1. I want my 4,000 lb car to stop like a 2,000 lb car and

2. It looks badass.
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xcidmigs
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Re: Brake Speculation

Post by xcidmigs »

Is it finally done front to back? Wheres the parts list?
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GTObert
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Re: Brake Speculation

Post by GTObert »

HEY! Chill out man! I told you I would let you know when it was done. I'm on assignment in the Colorado Rockies dong altitude testing, so I can't exactly change my brakes whenever I feel like it. Just back off and let me get to it when I get to it.

As a side note, I spoke to some GM engineers here and they think its a swell idea to toss these brakes on the Caprice. They were testing what looks like the new DTS, Camaro, and obviously Corvettes.
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GTObert
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Re: Brake Speculation

Post by GTObert »

Bad news everyone. There is no way this new rotor is going on the rear without a new backing plate. I'm hoping the 2015 SS plate will fit. I have no access to part numbers for this car though, so hopefully someone here can find it and then I'll get them coming.
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Gerome
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Re: Brake Speculation

Post by Gerome »

Most of the folks doing this swap are trimming the backing plate to fit the new rotor . You may not be game for that but that is what I have seen on the ss forum .
Chris_HT
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Re: Brake Speculation

Post by Chris_HT »

GTObert wrote:I'm doing it because:

1. I want my 4,000 lb car to stop like a 2,000 lb car and

2. It looks badass.
For the sake of those who don't know a lot about cars and come by reading your post : upgrading brakes on your Caprice WILL NOT make your car brake at shorter distance. The brakes we get from factory are well more than capable of locking wheels at high speeds - and even then we have ABS there to prevent full lock - fitting bigger brakes will not shorten your braking distance. It can actually hurt braking since bigger rotors add unsprung mass, larger diameter wheels required to fit over bigger calipers also add unsprung mass, making it harder for your suspension to keep rubber at full contact with the ground on "less than perfect" roads/surfaces. It will also hurt early morning braking since brakes will take longer to get to their optimal operating temperature. But that's not a point against bigger brakes - you will yield benefits in track conditions where repetitive braking is causing brake fade, and where better heat dissipation of large diameter rotors will maintain braking power for longer than your OE setup. Many people also prefer the braking feel of multi-piston calipers.

The only thing that can improve braking are better tires. And just to be clear - by better I mean better compound, not wider - wider tires don't improve braking since they make contact plane more compressed across tire surface. The 'rather tall' OE size of 235/50 R18 is already optimized for braking/acceleration because the it allows most amount of tire meat to make contact with the ground along the tire surface. Wider tires are, just like bigger brakes, better for track use - they allow less sidewall flex and have bigger surface and as a result can dissipate more heat allowing tire to take more beating.


GTObert wrote: 2. It looks badass.
YES IT DOES :)
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GTObert
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Re: Brake Speculation

Post by GTObert »

Tires are the limiting factor for stopping. However, since your factory brakes can't lock up the tires at highway speeds the increased clamping force, surface area, and leverage applied to the brakes will decrease stopping distance. I know because I can already stop faster with the fronts being changed.
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Navy Lifer
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Re: Brake Speculation

Post by Navy Lifer »

Gerome wrote:Most of the folks doing this swap are trimming the backing plate to fit the new rotor . You may not be game for that but that is what I have seen on the ss forum .
2015 SS rear brake shield info - http://www.ssforums.com/forum/588753-post55.html" onclick="window.open(this.href);return false;

The shield portion of the "backing plate" is not essential. Technically, GM calls the part a shield, but it DOES serve as the support (backing plate) for the park brake shoe & actuation mechanism.

The issue with using the 2015 SS shield on the 2011-2013 PPV is that the park brake actuation on PPV is still a mechanical cable-apply system, where the SS (2014 & 2015) uses an electric/electronic park brake actuator. I do not know if the SS shields can be used on PPV and still provide an anchor point for the park brake shoes in the same position as the "early" PPV's.

As I noted in the link above (from SS Forum), the shield portion of these parts can actually be cut away without any real harm, and as mentioned in an earlier post in this thread, trimming the stock shield on the PPV (same size as on 2014 SS) is effective in allowing the Brembo caliper to mount.
Navy Lifer
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Re: Brake Speculation

Post by Navy Lifer »

GTObert wrote:I know because I can already stop faster with the fronts being changed.
Tires are important, certainly, but we don't have a fair comparison unless you are using stock tires (18"), or another car with stock PPV brakes has your tires mounted to see what effect it has on stopping performance on the same vehicle - a blanket statement as you've made isn't really correct without factoring in some detailed testing standards--vehicle load/weight, fuel level, tire type, condition and pressure, ambient conditions, road surface specs, miles since brake service (for both your car and the baseline/comparison car, pad specs (if not OE or the same on both cars). etc.

Your "I can stop faster" statement leaves open the question of what was the condition of the OE brakes that were removed, what the pad friction coefficient of the new pads is compared to those that came off of the car, and (since you've installed Brembo brakes), are you still using stock 18" wheels/tires, or something else?

So, while I accept your statement, what are the other variables in your brake change that come into play beyond being able to say the braking is better solely based on the installation of the Brembo calipers and new pads + larger rotor(s)?

Nothing to argue--just give us the entire info download on specs of the new combination vs what was removed to see IF there's anything else that would further explain the "faster"braking statement.
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