New C7 owner - is the GS braking system enough for DE’s?
 

Congrats - that's a beautiful car.

If you've got the money, and you're planning on buying the AP kit whether you truly need it or not, I'd buy the AP kit now. I have no experience with C7 brake performance or longevity on track, but I do know you can't beat the AP brake kits. If nothing else the super thick pads will last much longer and will be cheaper than pads for the GS and the rotors will last forever. The AP kit will reduce your operating costs over all, and you'll never have to think about your brakes again.

The GS brakes will easily handle pilot super sports. They can handle the cup2s with the right pads too. Think about it, they handle z06 power but you're going to be hitting much lower speeds on the straights. If you say you're an advanced level driver you'll likely melt the pilot super sports fairly quickly. Watch their pressures and temperatures. 2-3 hot laps then take an easy lap or 2, then get on it again is the way to do it with those tires.

Thanks Bruno! What pads in your opinion work well with the Cup2's? I tend to like a pad that doesn't do a torque rise as temp goes up, and I don't like a ton of initial bite. While I've never run the DS1.11's they seem to be a better choice for me given the preceding sentence than the DSUNO. There aren't a lot of options out there for these calipers and before anyone says it, I don't want to run Carbotechs. I prefer a pad with very low compressibility and the CTechs feel a little to "soft" for me.

I've been running Stoptech's own SR-33 compound in their BBK on my M3 and like them a lot, though I could use with a little less initial bite. Just throwing that out there for calibration if someone's used both.

Followup question: the C65 has very bright metallic blue calipers. With Ti shims and with the factory cooling, should I expect the paint to discolor? I am just not familiar with how well this platform cools. That might be a deciding factor too, on whether to get the AP BBK up front so as not to ruin the finish of the factory calipers and devalue the resale accordingly. Yes, I could repaint them but I don't like that hassle of color matching and getting the lettering back to OEM spec.

Thanks for all the responses so far! Very helpful!

Oh man that's beyond my knowledge. Maybe Adam, the brake sales guy.

What's his screen name? I can hashtag him! Thx

You should consider the AP kit right away if you know it is coming. That will keep the OEM brakes mint....pads rotors and calipers.

The bright calipers would surely change color at least some and the heat checked rotors will show as well.

There are plenty of pad choices for both the OEM Z06 brakes and the AP kits. Cup 2 may not be a Hoosier but it’s close enough to be pretty aggressive with pad selection. The Raybestos compounds have fared well.

Yeah I'm leaning towards getting the AP kit up front.

Can anyone with experience with these kits confirm this assumption: since I am not in a Z06 or other high HP car, and since my use case is DE + DD and not racing, let alone endurance racing, I don't need the 9668 front caliper. I am zeroing in on getting the 9660 caliper with the 372mm rotor, and the rear BBK of which there's only one choice from Essex.

Anyone think I would be making a mistake by not going with the 25mm pad option? Money is a real object to me, so I want to only buy what I need and no more.

Thanks!

If your wheels clear the wider caliper I would get it. Pad cost and maintenance go down.

We have a number of clients with these brakes.

-Ken

Hmm, that's a fair point. Garsh.

I can say that the 6 piston Brembos have vented pistons and are good for a 80 degree Fahrenheit temp reduction, or at least GM says so.

Compared to? The previous gen brakes?

Sorry, I'm new to this platform so I appreciate the knowledge!

I think so I rebuilt my 6 piston Brembos from a CTS-V with the vented Pistons on my 5th Gen Camaro SS.

I've priced out the stock brake setup with pads and shims, and both AP racing kits (with the 9660 and 9668) and it's obviously a significant difference between the stock setup and the AP. That said, between the two AP kits, we're talking a 4.8% increase in kit cost and a 6% increase in replacement pad unit cost, but with a whopping 39% increase in pad thickness/life. It really does not make sense to get the 9660 if the 9668 fits. Thanks for that common sense, KNSBrakes!

However, I think what I'm going to do is run the stock brakes with the Ferodo pads and shims for a season and if I end up outgrowing them (aka cooking them!) I'll purchase the AP kit next season and have the stockers serviced and refinished for the next owner.

That's what's making the most sense to my pocketbook right now, given I still have to shell out some coin to put PPF on the entire car (I'm going for it!).

I have the 9668 calipers with 372 mm rotors on my Z06 and have no problems with wheels requiring spacers. The stock wheels fit over the brakes with ease and the 18x11 CCW Corsair C10 wheels I used on my C6Z work fine on the car as well. There are other forum members who are using the same size 18x11 Forgeline wheels with no issues as well. When I have looked for potential wheels to use on the Z06 I haven't really found a lot of options. There aren't a lot of companies that make track capable wheels in the sizes used for the Z06/GS. It isn't like the cars that use smaller wheels that have so many choices it is hard to decide which one to choose.

No spacers required as long as you order the proper offset or use a stock size wheel with the same offset as the stock wheels. I suspect stock size repros might work but the issue with them is due to the less efficient casting methods used by the manufacturers the spokes may be a lot thicker thus encroaching in the caliper space.

I don't do enduro's either but the thicker pads last through several DEs reducing the cost of consumables and the frequency of changing pads at the track.

As for what happens to the stock brakes on the track. That bright blue color will be diminished. My car came with the ceramic rotors and the calipers are red. I went through 3 sets of front brake pads and the calipers got dark spots where the brake dust built up and couldn't be removed no matter how much I tried unless I wanted to use something that remove the paint. I think your blue calipers will show the effects even more than the red calipers.

Here is what mine looked like after 3 days of track duty with the BMW Club at VIR. This picture was taken after I attempted to clean the calipers.

https://cimg3.ibsrv.net/gimg/www.cor...b7f19057b6.jpg

https://cimg5.ibsrv.net/gimg/www.cor...97f380c719.jpg

The dark area got worse over time and there were more areas where dust tended to collect while on track that got bad after several other events. The spots are definitely visible to the casual passer by who happens to be looking at the wheels.

The dust will be worse with the Ferodo or other pads that aren't the same as the stock pads used with the ceramic rotors which leave barely any visible dust when street driven.


Bill

I’d be glad to quote further if you are interested. There are other pad options as well.

Just PMed you friend.

I sent an email response to the OP, but I'll post here for the benefit of others in the same position.

In this situation, I would consider the wider CP9668 calipers on the front of this car. It definitely doesn’t need the wider CP9668 kit. If it were a base or Z51 car, I’d definitely push the owner towards the narrower CP9660. The CP9660 pads have plenty of mass/thermal capacity, and he's never going to fade them or have any troubles. In this case however, the stock wheels will accommodate the wider 9668 caliper, and they offer 40% more pad thickness than the 9660’s at roughly the same price across most pad brands. That will dramatically reduce consumable costs when one looks across the next five years, and the difference in initial purchase price between the two kits would be made up by the time he's run through his second set of pads. The rate of pad set consumption is going to be considerably slower with the 9668’s. Keep in mind that pads burn more quickly the thinner they get. In other words, if one uses 1mm of pad material per 20 minute session with a brand new set of pads, that number is likely going to be something like 1.5mm or 2.0mm of wear per session as one gets closer to the backing plate.

The weight difference between the 9668 and 9660 isn’t so great (less than a pound for the caliper), and I wouldn’t worry about that difference unless you were chasing hundredths of a second under tight racing conditions. The pad savings will be more meaningful to the typical HPDE enthusiast or club racer, when compared to the small weight savings.

Conversely, looking down the road to when you sell your car, the buyer pool would be slightly larger for the CP9660 kit since it will fit behind OEM wheels on base and Z51 cars.

Weighing all of the above, I think the pad savings of the CP9668 will pay dividends in this particular situation. If it were my car, that’s the route I’d go.

In terms of the OEM blue calipers changing color, I think that is a valid concern. Blue doesn’t tend to have the best color retention. Black is best, followed by red, then yellow, blue, etc. We’ve had some F80/F87 M2/M3/M4 guys with some fairly major color shift on their blue calipers after a very short bit of track time. They start turning an ugly shade of green, check out the inner caliper half in this blog post:

https://www.essexparts.com/news-blog...type-installed

If I remember correctly, the owner had only two track days on his blue OEM calipers!


https://cimg2.ibsrv.net/gimg/www.cor...e900b68b0e.jpg

Our CP9450/365mm rear kit is the perfect complement to the above, and it retains the parking brake, etc.

I’m not familiar with the StopTech SR-33 pad compound (they started offering those after I left the company), but the Ferodo DS1.11 is a perfect starting point on pad choice. It’s a moderate mu pad, and gives a great baseline setup. It lasts a fairly long time, and it’s much easier on discs than some of the competing pads our customers have tried. One can skip the titanium shims with our setup. The StopTech calipers use aluminum pistons, and the Ti shim is good crutch on that setup. Our system uses stainless steel pistons however, and we don’t see the same type of fluid boiling issues with it. Our pistons are also ventilated, which allows more air behind/into them. That, coupled with the Radi-CAL design flows considerably more air through and around the pistons. The large 372mm discs also absorb and shed more heat than what this customer has been running on his M3. We just don’t see fluid fade issues. To my knowledge, we’ve never had anyone fade our 372mm system thus far, and that’s on big power cars on tough braking tracks.

If budget is an issue, I’d suggest starting with the fronts now and adding the rear later when budget allows. The front brakes take far more abuse on these cars than the rear. I always tell people to invest in the fronts, as that is where the greatest ROI will be. The temps you’ll see on the rear will not be as high, and the likelihood of caliper damage/color degradation is not nearly as high in the back. I’d suggest starting with the front kit only. That will save the OEM parts in their pristine state, and prevent the need to waste money on new OEM parts when the car is passed along on the used market (hopefully to me...I love this model! :D). The OP be able to cash out on the brake kit at that time. The net result will be that he is bringing a couple thousand dollars in for the AP BBK, rather than spending that much on fresh OEM parts that he'll simply hand over to the new owner. We have matching Ferodo pads for the OEM rear calipers, so he'll be able to have a properly balanced setup. That setup, coupled to some good fluid will do everything you need it to do (we suggest AP Racing R2 to R4 range). Also of note, the Ferodo DS2500 sport pad can be swapped in with the Ferodo DS1.11 without having to re-bed everything, and one doesn't have to worry about cross-contamination, uneven pad deposits, and judder. The DS2500/DS1.11 combo is our most popular, and seems to work great on just about every type of car we deal with.