The Autoblog Project Garage: Big-brake install, Part II

With our transmission project on hold while we await the arrival of some parts, it was finally time to open up the large and heavy (81 pounds!) box of Kore3 brake parts that showed up on our doorstep about a month ago. We covered the selection process in Part I, and now it's time to dive in and see exactly what we received.

We wrestled the box from our front porch and out to the pole barn with the aid of a two-wheel cart. Consider this a public apology to our local UPS driver.

Breaking out the trusty disposable knife (the one that always breaks on us while we're forcing a cut, and slices up our knuckles), we make the first cut while trembling with anticipation. OK, there wasn't much trembling - we reserve that for engine parts.

A nice set of braided stainless-steel brake lines and some miscellaneous mounting clips were the first parts that we stumbled upon.

Next was a caliper abutment bracket. The function of this part is to mount the caliper to the spindle, while providing a means for the single-acting caliper to slide upon its guide pins. This is an OEM GM part, so finding replacements in the future should be easy if the need arises.

Here, we've got a bag of caliper slider pin hardware. It's excusable if you don't find this exciting.

Ah, now we're on to the good stuff. Here's the custom-machined hub that forms the heart of the kit. This part contains the bearing races and provides the correct 5x5" lug pattern and center registration feature to properly locate the rotor and OEM wheel.

Another gratuitous shot of brake part pornography.

It's a nice part when viewed from any angle.

Here's some more "boring" stuff - a set of wheel bearings, grease caps, and a set of spindle nut hardware. It doesn't look exciting, but it does hopefully do a decent job of keeping the front wheels attached to the vehicle.

Ah, here's some more pretty stuff. We went with the red powdercoated Z06 calipers instead of the standard black coated parts, just for a bit of visual impact.

The "cooling fins", shown here, aren't as much about cooling as they are about adding strength and rigidity to the two-piston aluminum caliper.

This is a OEM Corvette ceramic brake pad. They're rumored to be good enough for John Heinricy's autocrossing exploits, so they'll probably more than OK for us.

These caliper adapter brackets, which will allow the mounting of the abutment bracket to the OEM spindles after a bit of modification to the latter part.

Seeing as how this is laser-cut from 5/8" steel, it's hard to question the robustness of this part.

More hardware; in this case, it's the 1/2" bolts that are required to mount the adapter brackets to the spindle.

And finally, we arrive at the real reason for this conversion - the beefy 13x1.25" Corvette rotor. This is the largest rotor that will fit under the stock Impala SS wheels when using the Corvette calipers. This particular part has been modified by Kore3 to add the 5x5" holes for the stock lug pattern, and to open up the center hole to allow it to mate with the hub.

The difference in size between the Corvette rotor and a stock 12x1" rotor is shown here (sharp-eyed readers may note that we're actually showing a stock rear rotor here, but it's basically the same dimensions as the stock front rotors).

The additional diameter is welcome, but what's potentially more important is the additional quarter-inch of rotor thickness. Hopefully this allows for the improved heat dissipation that this car requires when pushed hard around a road course.

Oh, yea, there are some detailed instructions as well. Presumably, those will be important at some later point. We took a quick skim through them and it appears that they're packed with plenty of detail. The real test will be during the installation process, of course.

We also picked up a new set of spindles from the local GM dealer for a cost of about $140 for the pair. We're showing here the mounting features for the stock brake caliper; these will be removed to allow the installation of the new adapter bracket. It'll mount to the nearby holes for the OEM brake shield, after those holes are opened up and tapped to accept the 1/2-13 mounting bolts.
That's all for now. Once we finish up the transmission project in another couple of weeks, we'll finally get around to installing these beautiful parts.












Reader Comments (Page 1 of 1)
Kamil 2:13PM (7/25/2006)
what's the increase in upsprung weight? (per corner)
please weight the new and old parts and compare. :)
Reply
Bob-o 2:29PM (7/25/2006)
You spent HOW much to convert to 2 piston sliding calipers? Wait, don't tell me. I don't even want to know.
Reply
dumb 3:53PM (7/25/2006)
Or you could buy a sports car.
Reply
jm 4:02PM (7/25/2006)
Question: Do bigger brakes actually make you stop faster or just offer fade resistance from increased head capacity and shedding from the larger rotor? It seems that tire traction would be the limiting factor in stopping distance and most stock brake systems have the ability to lock up the tires. So if you don't race the best choice from a performance standpoint would be to stick with the stock system. Any thoughts
Reply
Chris 4:08PM (7/25/2006)
Why's it always have to be about money? The guy likes the car he's got and just wants to boost the performance.
Brakes are an often overlooked part of the performance package. An upgrade will offer the ability to driver harder into a corner and do it more often with less fade.
More stopping power to you guys!
Reply
Brian 4:21PM (7/25/2006)
#4 I asked this question before and this is how it was answered: Smaller rotors do indeed provide enough torque to lock the tires, but only in a spikey, not easily modulated to kind of way. With bigger rotors you are more easily able to modulate to that point and therefore are going to realize shorter stopping distances becuase of your ability to go into a zone where previously you had to skip through on the spike to locking your tires.
Reply
Russ 5:05PM (7/25/2006)
When I installed my Wilwood kit on my '03 Cobra, I DECREASED unsprung weight by around 19 lbs at each front corner.
I went from large single-piece iron rotors to 2 piece iron rotor/aluminum hat rotors. I also lost weight going from the 2-piston iron calipers to the 6-piston aluminum calipers.
The calipers bolted right up to the stock spindle mounting points via an adapter bracket. No mods to stock were required.
Stopping distance over stock has decreased noticeably. Fade resistance is much higher as well.
I would say for the vast majority, stainless braided lines and higher performance pads would be an economical upgrade and get you most of the performance as a big brake kit (on the street). If you're interested at all in road racing or autocrossing, this type of a kit is well worth the investment.
Russ
Reply
epilonious 5:19PM (7/25/2006)
In addition to Russ' excellent comments, it's probably prudent to point out that a race setup like this will dramatically decrease the chances of boiling the brake fluid. Nothing like having the pedal sink to the floor in the middle of any type of enthusiastic driving to make your heart sink.
Reply
Eric Bryant 6:53AM (7/26/2006)
Kamil,
Good question on the weight issue - I'll let you know. I suspect it'll be a step in the wrong direction :(
Bob-o,
You may not want to know, but others might like to learn that this kit was $1085. That's a bargain, in my book. If you wish to contribute to my bank account, I'll go back and upgrade my calipers to a 4- or 6-piston opposed setup, but until someone else starts paying for my parts, I'm going to be forced to choose components based on value. I also like the fact that parts for these calipers can be found just about anywhere.
epilonious,
That is exactly the reason for this upgrade.
Just for everyone's benefit, the stock 12" braking system was capable of producing 60-0 MPH stops of about 117 feet. That's pretty good for a car of this weight on street tires. The problem is that I'd boil the fluid after only 2-3 laps on a standard road course, and that's not exactly "confidence inspiring". Therefore, the whole point of this exercise is to get some more thermal absorption and dissipation up front.
Reply
MikeW 8:48AM (7/26/2006)
How heavy are the stock 17x8 impala SS wheels?
25 lbs? That is a good chunk of thermal mass. Take some anti-seize compound to the mounting faces of the brake rotor and wheel and the wheel becomes a heat sink.
Reply
epilonious 9:53AM (7/26/2006)
Are their any braking gains to be made in swapping out the brake fluid to more boil-resistant stuff?
I ask because group of friends and I are tuning up an old Merkur XR4Ti for the grassroots racing challenge in October. While said merkur only cost $900 and came pre-race-ready (roll cage and one seat) it also came with pre boiled brake-fluid. We have since spent our limited budget (grassroots racing declares you can only have $2006 worth of parts in an entry vehicle) on replacing the original turbo with a Haldex off a turbodeisel. Thus, I'm afraid we will not be able to upgrade the brakes with more heat-resistant hardware. Will getting better fluid help anything? or should we just get used to bleeding the brakes between runs?
Oh, and if you wanna see the beast: http://www.epilonious.net/coppermine/index.php?cat=8
or read about the beast:
http://www.epilonious.net/phpBB2/viewforum.php?f=16
Cheers!
Reply