GunKata

Guys, I've done research and have seen the going "back" to C5 brackets/rotors and have now just seen that it appears the Z brakes "aren't that good" by many guy's standards Bad thing is, I've got a used set on the way. I do about 3-5 track events a year and was thinking that these would be beneficial for stopping power, but unfortunately I did not do my research well enough as I am seeing many threads and posts that seem to.. well, discredit/state that the Z brakes aren't that good

Is this the case? should I even bother putting these on now? Please don't address the C5 route or better pads for me, I am simply trying to figure out if the Z brakes are effective and would think that if they can stop the Z in a quicker amount of time, that they would be able to stop a base model car as well. Are these not the same brakes GM used at the 'ring? I would have to see some benefit from these, yes??

Thanks,
John

GunKata

bump

John Shiels

pads are thin, wear fast and expensive otherwise they should stop you with a good compound. That is what I have read here. They can throw them away after using them at the N Ring can you? 3-5 events a year I guess it is affordable depending how hard you are on brakes and your wallet size.

rudyarias

They are the same that are used on the ring as with the C6 Z06 (J56) brakes. The C6 Z51 brake set up is much better than the C5 in design and function. The cross drilled were the only rotor design (and different cast) that held up during the NurburgRing (at first C5) C6 development. Second, the C6 (slightly thicker) spindles and caliper brackets are stiffer addressing the taper issues found with the C5 Brakes. Third, the caliper itself is of a stiffer aluminum alloy casting that is stronger than the C5 caliper.

I used the C6 Z51 brake set up for three years before moving on to the current (C6Z06) J56 brake set up. At no time did those cross drilled rotors fail using Wilwood H pads at Road America (in my book the true test for brakes). The only characteristic from hard braking is the outer side showing stress cracks with the inner side clean.

Keep in mine that the brakes on your car like the Germans are designed for driving on the street with occasional track use. Next time you're in the paddock at a HPDE, go visit the BMW guys and check out their stock brake set up.

If anything its not about hard braking into apexes, its really about brake modulation to maximize your exit speed. Be a driver not an American, you are driving on a road course not a drag strip. The NurburgRing is 21 kilometers in length which hard braking is not done or recommended to survive that course. That is why it earned its nickname "The Green Hell".

Poppy's Vette

I've not read any negative posts about the Z51 brakes themselves. I think the only reason there are some (me included) who run C5Z (or base C6) brakes is because the rotors are cheaper to replace than the Z51 rotors. If I could find a rotor available for $45 to fit my Z51 setup I wouldn't even think of stepping down. Remember, it's not a complete brake swap. We are using the smaller brackets to fit the smaller rotors but the Z51 calipers and pads are still there.

Am I missing something in your question?

rudyarias

Cost is the key factor with a lot on this forum. Its why they cling on to the C5 rotors. Unfortunately, that will eventually go away as costs for everything are steadily increasing. Brake components like gas, oil and tires are a constant expense. The money some spend on Big Brake upgrades for the sake of saving money is not the savings one perceives. The actual upgrade expense negates any savings considering the average life expectancy of a street/track vehicle is about three years. When that car is paid off, most will trade/sell that vehicle to obtain something better/faster to continue the upgrade cycle. So much for my opinion.

GunKata

Thanks everyone, and thanks Rudy, you are always a good source of information and a good driving instructor

pcervone - I am specifically asking about the C6Z06 brakes as an upgrade on a Z51 car.

If the perception is that better pads on the Z setup helps, then I will keep these, put them on, and get better than OEM pads and keep it at that.

Also, Rudy had a good point about cost savings vs. trading up every few years. I hope and plan to keep this car for quite some time.

Any more opinions on the Z brakes?

Thanks again,
John

rudyarias

John, thank you very much for your kind words.

I switched to the C6Z06 (J56) Brakes a little over a year ago. I've experimented with padlettes and padlette combinations. The PBR J56 brake calipers produce a brake torque that is easier to modulate during heavy braking than the C5/6 calipers. I discovered that by using padlettes that are two mm thicker, their life span are essentially the same as the C5/6 pads. The key is the first pad on each side are the ones which will wear the fastest. I usually go with a harder (XP8) padlette then the rest with more aggressive (XP10/11) padlettes. I also found the one piece pad or padlettes from Cobalt Friction to be the best so far overall with the J56 calipers in fade resistance, modulation and wear.

During the NCM Spring Mountain event last November. I had a great conversation with Steve Ruiz of StopTech about PBR's engineering philosophy with the J56 caliper. He felt it was a brilliant design with the use of the padlettes to create a brake torque without the need of a bigger master cylinder or "additional valving" within the caliper. The only issue which we both agreed on, are that the PBR J56 calipers are casted instead of forged. The only modification I've made with the J56 calipers were fitting them with stainless steel pistons front and rear. Jeff of Elite Engineering performed a meticulous effort in making the pistons. For street/track use the J56 calipers are more than adequate for driving HPDEs/TTs.

I have a close friend Miguel Caparros, you would not believe the braking performance he got out of the stock, solid, brake rotors and stock rear brake drums on the Bmw 2002. He designed a very effective cooling system for the fronts with a misting system that removed huge amount of heat. He also made a "legal" brake fluid cooler by coiling a 5ft length of brake line and blowing lots of air past it. The rears were along for the ride and only contributed 15 to 25 percent of the stopping power, so they survived with simple cooling by air. Religiously after every session he always replaced the brake fluid and bled the brakes. He brought this same set up to the Rolex Porsche team.

Heat will always be the issue. If you can get rid of the heat fast enough even an American could make the brakes last

Unfortunately for most on this forum, in the real world part of the learning and the talent is going fast without burning down the brakes or the tires in a 20 minute session.

John Shiels

I have saved countless dollars with my Wilwood SL6 brakes. Pads are cheaper and last over twice as long and perform better. Wilwood being America has made a great caliper at a steal of a price.

GunKata

Rudy, thank you so much for your input. I must be one of the few oddball Americans because I've been able to have the stock pads last quite well for a few events

Please excuse my ignorance, but the XP pads are Hawk pads, yes? I believe I am understanding that you use the harder pad, XP8 up front and then the other padlettes are the XP10/11s. I can see the logic behind that. I will also have to look into Cobalt Friction as I am not familiar with them/that company.

The Z brakes actually just arrived today, and good God, they are HUGE

If they are more than capable, I will go forward with putting these on in the next month or two - still have Autobahn and Grattan in the next few weeks and will go with the new Z51 pads on the car still. But if these will be adequate I will put them on and stick with them. Are the pads that hard to change out? I am just concerned I am going with something that makes sense, although spending any more money than I have ( I actually spend hundreds less than the new price) on the Z brakes just doesn't make sense to me. Wilwoods would maybe be nice, but not at a cost that I am sure they are asking for.

I think maybe its all relative - I am upgrading already capable brakes on a $50K car, and other guys are upgrading already capable brakes on their $70K Z06. Still, I think I may be one of the different Americans because I don't usually burn through pads too quickly

rudyarias

The XP8s and XP10/11s are CarboTech. The padlettes on the bottom of the caliper wear down faster because its the first in the sequence on the rotor. GM did some testing with Cobalt Friction, Wilwood, Hawk, CarboTech, EDC, PFC and OEM pads on PBR J56 brakes at VIR last year. Cobalt Friction won hands down. You can use also use DBA slotted rotors that are sold through Tire Rack.

The beauty of it all is that the PBR J56 calipers are a direct fit to your C6 without the need to upgrade the spindles like I had to on my C5Zs.

As for being one of the FEW Americans who doesn't burn through pads. Welcome to the club

John Shiels

brakes life will depend on how fast you go, speed carried through corners, and driving style.

rudyarias

To an extent John, the car's speed and mass are factors but its how one brakes into/through the apex that really determines longevity of brake rotors/pads.

John Shiels

yep that is what I was trying to say.

0Vector Vette

GunKata John,
I am a Cobalt Friction dealer and have pads for the C6 Z06 calipers in stock. These pads are a significant step up from Carbotech or Hawk. I also have the SS Brake lines and Motul brake fliud in stock if you need either of them. My shop is in Aurora, IL. It is called Performance AFX Motorsports. The number is 630-844-0089, give me a call if I can help, I always love talking Corvette Racing!

Robert Finlayson

GunKata

Hey Robert, I tried calling the shop but couldn't get a hold of anyone or leave a msg.

As for as the Cobalt Friction pads, are these streetable pads or strictly track pads?

Rudy, thanks for the PM, I will try to contact you today.

I am still on the fence for the moment and will have to decide one of three options:

1. Go through with putting on Z brakes - make sure I know what the heck I'm doing with them/pads, etc.
2. Sell the Z's and get the Wilwoods up front - but what rotors? I have Z51 car.
3. Sell the Z's and stick with the Z51 setup, just get DBA slotted rotors and run better pads. Save $$$

0Vector Vette

Gunkata John,
I forgot to mention that I wouldn't be in till later today as I was on-line trying to register for the National Corvette Museum HPDE at Road America, which had an unexpected delay. I will be there soon. The Cobalt Friction pads I have in stock are strictly track pads. I also have a complete setup with AP racing 6 piston calipers that use thicker pads with a 2 piece real racing rotors. These rotors are vented correctly and weigh over 9 pounds less than the stock C6 Z06 front rotor! Give me a call, lets talk brakes.
Robert Finlayson

gkmccready

LGM has a bracket for the Wilwoods that'll let you run the C5 (aka C6 base) rotors. At $30ea instead of $80+ea how many do you have to go through before you didn't "Save $$$" with the other set ups? Plus the pads for the SL6 calipers are cheap at $180-$200 an axle set.

GunKata

Hmm... I am talking with Anthony now on possible setups here. I think i will possibly do the Willwood route.


Robert, no problem, I will let you know if I need pads but may end up ditching the Z brakes.

exracer28

I used the C6 Z51 brake set up for three years before moving on to the current (C6Z06) J56 brake set up.

What brake lines did you use for a c5 with c6 z06 brakes?