JimMueller

Any recommendations on a minimum 4-pot fixed caliper, 2-piece 14" rotor kit that fits nicely within a C5 Z06 rear wheel (chosen for balance of cost and weight) without any modifications to the OEM mounting hardware? I'm also considering a Forgestar F14 18x11; it's a little heavier but it may offer better BBK clearance(?), and I can use a small wheel spacer if necessary.

It would also be used for daily driving, so I'm nervous about the kits without dust boots. I'm told a GOOD 4-pot fixed caliper kit would be fine and there's no need for 6 pot, and to opt for the 14" rotor if it will fit. I've read mixed reviews on the Wilwoods, so I'm leaving them out of the mix for now. Also would prefer the paint to not discolor so I would prefer an anodized caliper; not much road salt here in Florida.

Baer Extreme+ - 14" rotor but only 6 pot
Brembo - 14" rotor but only 6 pot
EssexParts AP Racing - offers 4 pot 13" competition kit no dust boots, 4 pot 14.25" street kit with dust boots but not much caliper weight savings
StopTech - has 4 pot, 14" but not offered in anodized
StopTech Trophy - 14" rotor only in 6 pot

fatbillybob

Look into the stoptech T1 kit. It is a 4 pot (per our rules) 4 caliper kit. It was developed on my car for SCCA T1 racing. I have used it since about 2011 and only race on it. It is amazing and flawless in performance. In racing terms everything lasts forever. Since 2011 I have had stoptech rebuild the calipers once but they really did not need it. I did it for routine maintenance couple years ago. I have never had to change rear rotors. I change front rotors every 1.5 years. carbotech xp20 Pads I change after 3 race weekends. I could go longer on pads if I wanted to squeeze out more life. I bleed brakes before every race except when I'm travel racing. This year for example my racecar has been out of Cali since December 2016. It's last race of 2017 will be Runoffs in September. I have not bleed may brakes since December. I don't need to. The capacity and head room of these brakes is so good I can use cheap valvoline brake fluid from O'reilly autoparts and leave it in my brake system all year and just race. That's probably the biggest testimonial to how robust ST made this kit. ST rotors are called aero rotors. They are designated trophy rotors when you go to the floating pins that make the rotor truely floating. You float for racing make them more solid for street to reduce noise. Either is fine depending on application but the real point is the difference is which pin kit you buy to make the rotor aero or trophy. You can get calipers colored or anodized and after all these years of abuse my colored calipers are in pretty good shape considering I don't try and keep them pretty at all. Stopping power on the ST is amazing and confidence inspiring even on biggest braking zones coming off rovals like daytona 160mph into an infield course. Try trail brake with lots of good modulation and pedal feel on stock corvette components including playing nicely with or without the stock ABS. Pedal travel is stock because the ST engineers perfectly match the stock master to the calipers. The rear rotors are smaller than the fronts. That is ok you don't want any more rotating mass than you need and the rears do very little. The original AP/Hardbar brake system for T1 was just a front caliper solution. It had raced to numerous T1 victories so I would not get wrapped up at all in what the rears look like. You want a kit that is designed and balanced front and rear. There are many solutions out there. I go for the track proven ones. The buttermores have won SCCA national championships on the Stoptechs in corvettes. Oh and because of our class rules we race on the z06 rear wheels front and rear or use the F14 18x11 on the rear.

UstaB-GS549

I installed the Essex/Hardbar/T1 4 piston caliper kit on my car in 2011. It's the same AP 8350 caliper as the current Essex Sprint Kit.

My C5 Z06 is street driven and tracked a couple of times a year. It's been 6 years with no dust boots & no problems. Dust boots just burn up on track anyway.

I can slow the car with confidence at Road America and that is with the stock 13" rotor diameter which fits in both my 17" & 18" wheels.

A big plus with the 8350 caliper is that it uses the Wilwood 7420 pad profile. The pads are 20 mm thick, there is a huge selection of brands and compounds available AND they are about the least expensive race pad you can buy.

I use Prestone DOT4 brake fluid and probably only bleed it at the beginning of the season and maybe again half way thru. I never felt the need for more expensive fluids even at a track like Road America where you brake from speeds around 140 3 times each lap.

Call Jeff at Essex for an honest opinion about whether you really need a 14" rotor. Unless you go to a larger rotor in the back you probably will mess up your F/R bias.

This was taken a few weeks ago. I did wash the caliper before taking the picture, but the caliper still looks good after 6 years.

fatbillybob

That original kit won many races but used the AP j hook rotor and could fit the 17" wheel with a spacer. I was there when we had the prototype in our hands at dinner for that kit. Those where the days when 3D printing was called rapid prototyping and we had that brake assembly in plastic prototype. So here is some drama and this is how I remember it. If my memory is faulty I apologize.

Hardbar (gary claimed to be ex-engineer) and essex (jeff) were involved in the original kit design. Later Gary from hardbar disappeared and I started to heard of caliper mounting bracket failures from that kit as the race miles increased. Jeff at Essex distanced themselves from that original kit calling it a hardbar invention but now use the same parts from the original kit but with a newly designed mounting bracket. My point of bringing that up is I would make sure I got the new bracket. I'm not up on all that happened but check with essex to see if I'm right and you should buy new brackets for safety. I was there at the development with other T1 racers and Gary talked up his hardbar kit as an ESSEX AP collaboration. Gary had a coupe other things that did not work for me personally yet other T1 racers loved him and so I approached Stoptech.

Socko

There are brackets for willwood sl6 calipers around. I think KNS sold some and DRM maybe?

Getting into a 7420 pad is really the best option as UstaB-GS549 stated above. They fit under the stock wheels with a 12.8(base) or 13.4"(c6z51) rotor and under the stock 18 with the c6z 14" rotor. You can get a spare easy at most any part store. You can buy 2 piece rotors for any of the cars in stock fitment later on down the road.

I decided to make my own brackets and put the solidworks drawings on the forum here in the road racing forum. If you have access to a mill you could just cut some. The hard parts cost $600+pads and I had real brakes on my car.

JimMueller

If you run without dust boots on the street and it causes a problem, can I order the parts and rebuild at home, or should they be sent in for repair? I've also read that there may be additional brake maintenance needed with these road/track BBK's when they are used in a daily driver. Such as brake dust getting into the hat sliders and causing them to stick. Any input on how the maintenance schedule would change from an OEM solution?

The CP8350 caliper in the AP T1 kit is about 1.5lbs lighter than their CP96xx calipers, but the J-hook rotor weight on the T1 kit is about a pound heavier. They all lack dust boots, the 96xx calipers are 6pot in addition to having extra features. I've reached out to Jeff for compatibility questions.

For ST, there search engine leaves a bit to be desired, so I'm having a hard time locating their T1 kit.

JRitt@essex

I think this thread is a good example of the general misunderstanding of dust boots, what they do, and how effective they really are on a car being used on a racetrack.

From our website:
We are often asked by potential customers if the calipers in our kits require frequent maintenance and rebuilding because the pistons don't have dust boots. We are perpetually shocked by this question because it makes no intuitive sense. If you have a product that is specifically designed to handle the extraordinary high-heat conditions of track use, why would it require more maintenance when used under those conditions vs. brake components that were designed to cruise around on the streets at low speed and temperature?

Many people confuse piston seals with dust boots. All calipers have seals. They're the little rubbery rings inside the piston bores (see pic below). If a caliper didn't have a seal, your brake fluid would leak out around the pistons! OEM caliper seals aren’t designed to handle constant trips to several hundred degrees without becoming brittle and leaking. Our calipers use special high-temp seals designed for track use. They are the exact same high temperature seals used in NASCAR Sprint Cup, ALMS, DTM, etc. That means they are less likely to get brittle and wear out when used under high-heat track conditions, and they require far LESS frequent replacement and servicing.

Most aftermarket calipers are designed for year round road use, and as such come with a bellows style external dust boot like the ones shown below. The rubber boot stretches as the piston extends, and its objective is to keep contaminants out of the piston bore. It's a nice concept, but we've seen customers burn those up in a single 20 minute track session! Once that happens, you're simply driving around with some tattered, burnt rubber bits attached to your pistons. At that point they're providing zero benefits to you. If you're going to instantly destroy them when you go to the track, why worry about having them in the first place? We skip making that mess for you by eliminating them from our design.

On a caliper with no dust boots, you can accomplish the same thing that a dust boot does by simply wiping the sides of the piston off before pushing it back into the caliper body during a pad change. That will prevent the internal seals from being cut or damaged by debris clinging to the sides of the pistons. It's just that simple.

In summary, don't sweat dust boots if you plan to run your car on the track. They won't gain you anything!

AP Racing High-Temp Piston Seal


OEM Dust Boot Before Track Use


OEM Dust Boot After Track Use


Here's an OEM caliper off of a Gen. 5 Camaro with the 1LE package. This particular customer actually tried using aftermarket dust boots because the originals burned up so quickly...and you can see what happened to them.

JRitt@essex

No worries fatbillybob...I'm aware that you only know what you were told by Hardbar. Below is the history of how we became involved in the Corvette brake market (aside from supplying Pratt and Miller/Chevy with AP Racing brakes to help win Le Mans). Maybe I should rephrase that...how we became involved in the Corvette enthusiast brake market.

To clear this situation up...about 6-7 years ago Hardbar/Gary approached Essex looking for AP Racing components to design his own brake kit. Essex supplied Hardbar with AP Racing CP8350 calipers and 325mm iron disc rings. Those calipers and discs had previously been used in asphalt late model racing, but they were the appropriate size for fitment to Corvettes. Gary at Hardbar designed the brackets and hats, had them manufactured, sourced his own hardware, mated them to brake lines of his preference, etc. and sold those kits as the Hardbar T1 Kit. Those kits were not an Essex design. Since Hardbar was using AP Racing calipers and iron disc rings, we co-promoted his kit here on the forum and funneled all interested parties to Hardbar.

Eventually it became clear that there was a considerable amount of demand for a variety of competition brake kits for the Corvette. It also became evident that to properly support the AP Racing brand in this market, a certain level of service and quality was required. Given our staff, facilities, design experience, and decades of experience in professional motorsports, Essex decided that both the market and AP Racing would be better served if we designed and serviced our own line of competition brake kits using AP Racing components. We not only began designing and building our own brake kits for the Corvette, we did the same for other popular track car platforms (BRZ, Evo, STI, S2000, etc.). Those became known as Essex Designed AP Racing Competition Brake Kits.

One of the first kits we released was our own version of a CP8350/325mm brake kit for the C5 and C6. We designed and manufactured the brackets and hats in that kit from scratch, used the same hardware we use in pro racing, partnered with Spiegler for brake lines, created our own support system for caliper rebuilds, disc burnishing, etc. We also designed a six piston front kit and two matching rear kits. When AP released the Pro5000R Radi-CAL line of calipers, we integrated them into our program and built several front and rear kits around them.

Due to AP's confidence in our Competition Brake Kit program, in 2016 they authorized us to supply our Essex Designed Competition Brake Kits to any global AP Racing distributor. For example, if a customer in Germany wants one of our Competition Kits for his M3, he can ring up AP's exclusive German distributor and purchase one through them. We have the distinction of being AP Racing's only global partner authorized to do so.

To take that a step further with regards to the quality of our brake kits, we were recently chosen by Ford to design and manufacture the brake systems for their latest factory racecar, the Shelby FP350S.




Also FYI...I was the sales manager at StopTech for five years prior to my joining Essex (2002-2007), when they were just becoming more known in the market. I was at StopTech when the ST-60 caliper was designed. I was part of the decision making process when numerous Corvette brake kit applications were brought to market. When I came to Essex, I leveraged that experience for our own program. We looked closely at every tiny design feature in the StopTech kits, and made the corresponding features in our kits more durable, lighter, more functional, etc. Concurrently, our technical director brought a wealth of knowledge to Essex after serving as engineering director at Tilton for about 14 years (you can see more on our staff here). Although our kits have only been on the market for about 4-5 years, we believe they are the most potent option by a considerable margin. They offer a lengthy list of features and benefits that aren't available from other manufacturers at any price.

KNSBrakes

We have another run of these FSL kits on order.

We had zero failures on these and most intermediate to advanced HPDE guys were very satisfied.

No it does not replace the very well made AP koits Jeff has done. Those are remarkeable.

I do think the WW FSL kit we devised beats the 8350 kit though.

romandian

socko, what did you get for $600?

Socko

https://drive.google.com/open?id=0B2...1RTeDkxN0htZFU

That's all the stuff i believe. Its 20mm sl6 calipers. You will need jet nuts, and some shims too, depending on what diameter rotors you want to use. I setup the bracket to be shimmed out one shim as well. So you will need the shims for the caliper to the knuckle and want shims for between the bracket and the rotor to get it all fitting nice depending on the exact dimensions of your rotor.

Oh there is an arp stud they sell on summit that works perfect, that i ended up switching too.

All the pictures are in the zipped folder in the link. And i believe the last drawing was in the folder that had the zip but i dont recall if that is it or not and i cannot open solidworks drawings from home anymore. As the arp stud wasn't long enough for enough shim to fit a 14 on the 12.8" bracket. So I just had another set cut, as it was just aluminium cost.

a_ahmed

I used to run wilwood GT rotors and SL6 front and SL4 rear on my old 240sx, that setup was great although the corvette is much heavier...

I hate the stock c5z06 brakes, with several constant 200kph+ stops the brakes are done. With some hard stops the brakes are smoking.

I did HP+ pads, centric high carbon rotors, wilwood brake fluid and SS lines... The feel sucks the stopping power and response is mediocre... and the brake fade is awful.... The rotors start cracking and last very little.

I have been thinking of getting the hub cooling duct... but it still makes me wonder.. the feel and stopping power is mediocre...

Larger rotors and wilwood calipers would probably feel better, perform better and last longer... BP20 pads is what I used to run with great success.

If only someone would provide caliper bracket profiles which we could cut ourselves, buy the calipers and pads and say c6z06 rotors and call it a day...

Then down the line if I could get the GT rotors and aluminum hats in 14" sizes... instead of the c6z06 rotors....

The kits on the market are pricey... especially for some of us who are in canada....

SL6 Nickel plated with those thermolock pistons would be bomb...

a_ahmed

Interesting!

So this will work with 14" C6Z06 rotors? What about the GT vaned rotors and hats? Does Wilwood sell those hats and rotors individually?

JRitt@essex

Why not just buy one of our off-the-shelf kits and not have to think about your brakes again? If you add up everything you've purchased, and plan to purchase, you could have bought one of our brake kits and have been enjoying it the entire time. Please note a_ahmed that I'm not trying to single you out, etc. I think this is just a great illustration of what we tell our customers all the time, and shows a different way of looking at the situation.

Sunk costs after step 1:
Hawk HP+ pads=$150
Centric High Carbon disc pair=$120
Wilwood fluid (3 bottles)=$40
SS lines= $100
Round 1 Total=$410

Results: "The feel sucks the stopping power and response is mediocre... and the brake fade is awful.... The rotors start cracking and last very little."

Step 2:
Wilwood calipers and studs as shown by Socko= $600
Another round of Hawk pads for the Wilwood calipers= $150
More fluid to re-bleed system= $40
C6Z06 OEM-style, one-piece Centric disc pair=$230
Round 2 Total= $1020
Round 1 + Round 2 total= $1430.

Now you have to figure out how to get the calipers on the car. Billet brackets are going to cost you another few hundred bucks unless you literally have a CNC mill at your disposal. Even if that cost is only $200, you're now at $1630.

That doesn't include shipping costs, taxes, design time labor, installation labor, etc. If you place any value on your time at all, you're talking about another couple hundred dollars.

Results: You will have brake system that possibly performs a bit better than the OEM C5 setup, but still nothing to write home about. The problem is that you're basing the system around a disc that has proven to be a poor performer. The C6Z06 OEM-style discs are heavy, inefficient, and don't flow much air. As a result, they run hot. Everything downstream of them runs hot...hot discs=hot pads=hot pistons=hot fluid=hot caliper body=hot ball joints=hot hubs...and so on.
You will be burning through consumables (pads, discs, and fluids) at a steady rate, and you'll likely never had the performance you had imagined in your head.
Also, the value of what you'll have at the end of the day will not be very high...probably a couple hundred dollars residual value.

If you add 2-piece discs after the fact as mentioned, you're talking about another $800 sunk. That takes your total to $2430. At that point, you've spent very close to our price for our Essex/AP Racing Sprint Kit ($2599), and you still won't have a system that compares. Our system is lighter, will have better wheel clearance, more durable discs, stiffer caliper, and designed by pros. It will run far cooler and eat considerably less consumables, and it will feel much better. Best of all it requires very little effort. It comes in a box, you bolt it on, and you can typically have it within a day or two of ordering it. Here's a critical point...when you sell your car, you'll be able to sell your kit for about 65% of what you paid for it ($1700). There are some variables there obviously, but that's pretty typical of what we see our kits go for on the used market. If you buy for $2600 and sell at $1700, your out of pocket (ignoring spares) is only $900!

I was very conservative on my estimates of the real cost of piecing your own system together. The real cost is likely higher than what I used in my illustration, particularly if you value your time at all. Again though, the kicker is residual value when you move on to your next project car. Selling bits and pieces of brake components, or a kit that you put together on your own, is not going to be easy, nor is it going to get you much back on your investment. It will also take a considerable amount of time and effort to go down that route.

Over the past 15 years I've literally seen this scenario over, and over, and over a thousand times across Vettes, M3's, Porsches, STI's, etc. If you want superior performance, technical support, confidence in the components, residual value in the investment you're making, and the least effort expended, our kits are a no-brainer. Check out our blog if you want to hear it directly in our customers' words. Please do yourself a favor and take a long, hard look at the actual numbers before choosing a path. You might be surprised at what the numbers tell you.

romandian

and how do c6z06 calipers compare?

JRitt@essex

C6Z06 calipers are extremely heavy (about 10 lbs. each vs. 6 lbs. for our AP Racing six pistons) , they use tiny padlets that are 15.5mm thick and cost a lot of money (for what you get), they have terrible pins that make them hard to service, the painted finish burns and melts, the pistons are aluminum and don't reject heat very well, etc. Other than that, they are awesome! :p There are many threads on this topic...here's the first one that came up in a search. They look big and red when they're brand new, but that's about it. They don't do well under track conditions. You will always have guys come on here and say, "I've been running mine on the track since 2006 without issues." Anyone who has run them, then switched to one of our systems will tell you that they aren't even in the same ballpark on many levels...apples to oranges comparison. They are cheap on initial purchase, but you pay for them in the long-run with high running costs, spares, poor performance, etc.

Socko

Yeah i did it myself cause the brackets cost $30 for aluminium stock. If you had to pay someplace to make them may as well just pay kns.

Plain and simple there is a very legit benefit to using the stock rotors though. As the c5/c6 will tear up most all rotors you throw at it. It allows you to keep your brakes as light as possible while adjusting your mass for heat capacity for super cheap. And having most autoparts stores around stocking corvette rotors means even if you are super unprepaired you can go buy a $50-100 rotor and finish your day or get home or whatever. Sure you could get more mass in the useful area for less weight, but realisticly i don't think you can beat the track day per dollar of stock rotors.

I will miss my c5 with 20mm $200 pads and $70 rotors and $1200 of tires. When I end up having to replace my 15mm stock pads for $400 my tires for $1800 and my rotors for 350 each on my c7 gs.

ibjamin

Just FYI: Some Stoptech rear brake kits for C5 are on clearance sale on Stoptech site. $1450 for rear ST40 kit. Trophy kit is $1825. Good price for good kit.

G

dapopa9

The Wilwood AERO6 kit bolts right up and fits under the OEM Speedlines C5 Z06 18x10.5's wheels

http://www.wilwood.com/BrakeKits/Bra...on=C-5+%26+Z06

KNSBrakes

I looked briefly but have not seen this. Do you have a link?