X25

Thanks! I will soon have answers to some of these questions. I expect to receive my car around next weekend, and should also get the remaining of the parts by then.

Indeed, 4 point harnesses can cause you to submarine during accidents. To avoid this, OEM seat belts are only 3 point, and let your shoulder move forward during an accident, effectively making it impossible for you to submarine. The Schroth ASM harness also uses the same principle, and has a double-stitched section on the shoulder belt by the side of the center console. During an accident, the stitch opens up, and lets your shoulder move forward, blocking any possibility of submarine movement. This system works (I tried it myself(!)), and lets you use any seat in the car without having to worry about becoming a stress-bearing column (what happens when you're pinned to the seat with a 5/6 point), and avoiding the risk for submarine, too.

The OEM seats are tested with your car, and are certified safe by the manufacturer. Moreover, it's not clear what happens when you disable the side airbags: even if you emulate the side airbags, will the rest of the airbag system function properly during an accident? What happens when they deploy fine, but in the absence of the side airbags? They are certainly designed to work in tandem, not alone. Considering all these, it becomes not a good choice at all to use aftermarket seats.

Long story short, I'm excited to test out the combination. I imagine SharkBar was also designed for OEM seats (even the pics have OEM seats shown), so I think the angles will work just fine. We'll see!

X25

Just realized DBA has front ring replacements for the Z06 (iron) front rings:
https://www.knsbrakes.com/c/car-seri...2FCorvette+Hat


With the Corvette Forum discount (CF5OFF), it becomes $706 shipped per pair; not bad considering it converts the Z06 brakes into curved vane rotors! Ordered a set as spare.

X25

Rear calipers will be delivered on Tuesday, which will mark the time when I received all the parts!

Received DBA 5000 T3 rotor rings


Just the ring is 23.4 lbs; heavier than I thought. Perhaps that 'high carbon content' they mention cause a weight increase, too.



Also received the Z06-spec rear 2-piece rotors. They're pretty heavy at 24.8 lbs (vs. 18.1 lbs OEM Z51 rears!!!), since they need to accommodate the hand brake at the hub. I'm actually pretty bummed about the weight increase


The DeWitts radiator for C7 looks substantially smaller than their Camaro-spec radiator; I suppose there's not much space to fit anything bigger? It weighed 13.7 lbs.


This is the Camaro rad vs. stock (Camaro) radiator.

X25

Check out what the C7R race car uses. Looks like 295 or so fronts might indeed be the ideal, and we don't need much more at the rear:

Kamran

Careful! Look at the rotor sizes (Z06 vs R), then also look at widths...not the same car.

X25

I obviously did; I don't get what you mean to say.

The point here is that they were able to make the car work very well and competitive with almost square setup. I wish they listed weights, too, but it's easy to find (publicly available).

Kamran

Ah, sorry! I thought you were thinking that particular set up (wheel size) would fit Z06, GS. I was just trying to bring attention to the smaller rotors of R (14"+/-) vs Z06 (15"+/-), as well possibly larger fender space (wider body) that accommodate that particular set up.

On another note, is that for real? I mean is that just a collector car, assuming buyers have no intention of ever racing it? Or are they really thinking smaller rotors are more appropriate for a race car???

X25

That car is the race car that wins races in its class; not something available for the public, which makes it even more attractive to look up its specs : )

I think you're talking about C7R edition Z06, which is just a regular Z06 with track options and an additional appearance package.

Regarding rotor sizes, keep in mind they are thicker than the iron brakes on the Z06, not to mention the massive cooling ducts and AP Racing calipers with very thick pads.

Kamran

Huh! My bad, Yes I was thinking of the one available to public (using my cell phone to read). I would have never thought they would have revealed their race car specs!?
Take a look at the thickness, it's actually 1mm thinner in the front vs Z07 package!? With all the cooling and all, it's still very interesting they are going w/smaller rotors which has a smaller heat sink capacity!? Looking at these cars at night, the entire rotors are red hot, so I'd imagine bigger heat sink capacity as well as higher torque would have been the ticket, but what do I know!

X25

Keep in mind, the Z07 brakes are carbon-ceramics, and these are iron; completely different material and specs for heat capacity. I would not be surprised if those steel rotors have more heat capacity than the carbon-ceramic brakes. After all, since the Z07 rotors are essentially carbon flakes glued together which has heat isolation properties (like any other glue), I'm sure they are much more efficient at shedding heat anyway. OK I'll stop here, so I don't start yet another CCB vs. iron war, this time on my build thread

BaylorCorvette

So, how do you read racing slick tire sizes when comparing to street tires?

30/68-18 & 31/71-18? I assume the 18 is the wheel size but other than that I'm lost. 30 the width in centimeters?

X25

Yep, 30 is in cm, so it's 300 to 310mm, likely identical to our 305 spec. 68 is 680mm overall diameter, which is 26.7". The wheel is still in inches : )

SBC_and_a_stick

The race teams only build them big enough to finish the race. You can do the same and change rotors after every track day.

I'm using 15.5" x 1.3" front iron and 14.4"x1" rear iron. They are heavy as hell but they stop the car every time, last a long time, and keep the pads in good shape. Cheaper but slower. If you really want fast you have to go carbon carbon.

Kamran

Funny, I've actually seen and heard of guys with the carbon rotors "accelerating" real fast "off" the track, in the grass! ...They swapped their carbon for steel, and all was fine. One big reason I absolutely have no interest in the Z07 "bling" package.


You can go faster with 14", yes a little. But you slow much faster with 15"!
Driving an underdog w/no Hp, a lot of it for me comes down to how late I can brake and carry it through....

X25

He's talking about (for racing only) carbon-carbon rotors, not carbon-ceramics

Kamran

Ah yes, missed that. Just re-read it again...

X25

We should note here that the C7R is much lighter than our cars, and its brakes are very thick; they won't be too light for sure. They are also meant to last for a 24 hour endurance race; I don't know what could be harder than that; they are definitely not under-built.

Himm, are you using iron rotors the size of carbon-ceramic rotors, perhaps using the Z07 brakes with irons? I hope you can at least use narrower annulus to save some weight. If the car doesn't need that much brake, as you also stated, you're probably killing your performance. You could just sell those brakes for a very good price, get regular Z06 iron brakes, and perhaps use something heavier duty like the DBA 5000 T3 replacement rings, which are curve-vaned (directional) unlike OEM rotors? I don't know how much of it is 'felt' on a 650 HP car, but heavy brakes screw up all the suspension tune.

SBC_and_a_stick

Carbon carbon vs. carbon ceramic... . Either the carbon carbon or carbon ceramic are better than iron in any platform, momentum car or not. Better than tiny iron brakes too. By the time you get iron to weigh the same it's a flimsy sheet of metal.

Iron rotor size mostly comes down to cooling. You can take a tiny OEM rotor and use a race pad on them. On almost all cars it will lock your wheels until something overheats a few laps later. But for the first few laps the small rotor is lighter, faster, and stops the car as well since the tire is the limiting factor.

The Z07 brakes work. I had them for 7 track days. They rock. It's easy to modulate, they take all the heat, and they weigh half as much as the iron rotors. I changed them out because they were almost at minimum weight, only one track day left on them. Therefore they are too expensive for me, but high rollers can afford them.

The Corvette race car is forced by the rule book to run iron...

SBC_and_a_stick

The race car also has much better ducting. You bet that makes a difference.

Yes, I'm using the Girodisc replacement, same size as CCB rotors. Stock CCBs is what the light weight brake set is for this car. Everything else is portly. So even with a smaller iron disk I still consider it adding weight to the car, rotational mass, and extra load on the suspension. You lose performance with iron no matter what. I'm more than happy to scrub off some speed to lower my consumables to 1/4 of the cost, have pads that work until worn to the backing, and rotors that last a long time and don't crack through. 15.5" is the right size for this car (mine weighs 3,600 lbs). Everyone reviews brakes when they just buy them new. But what is the review with a fast driver when the rotor is worn and pad's are not at full thickness?

You can think about it this way. When my rotors are on their last track day, and they pads are almost fully worn the weight may be closer to the full weight of a brand new smaller iron rotor. My car gets faster as the brakes wear!

I'm pretty sure the Girodisc would be a great endurance brake kit. I prefer that for HPDE especially when cheap.

X25

I'm surprised you gave up so easily. ZL1 is 580 HP, a bit lower on power, but it's 4050 lbs MINIMUM without the driver, yet its 14.6" rotors are adequate for the job. They are actually same calipers (except vented pistons) as Z06 iron rotors, but their rotor is curved vane (as opposed to Z06's undirectional), and does the job admirably.

There are DBA 5000 T3 directional replacement rings available for the OEM BRembo hat, so you can easily convert your rotors to directional. This should be more than adequate for your car, yet they will not be nearly as heavy as your overkill iron brakes.

What's more, you can actually MATCH or do better for the unsprung weight. I have not done the analysis for C7 Z06, but I did so for Camaro Z/28:
http://www.camaro5.com/forums/showth...&postcount=114
As you can see, a decent BBK system is only 2 lbs or so heavier than the CCB. That said, you can easily more than offset that by reducing your wheels to 18/19 from OEM 19/20s, mostly dictated by the size of CCB brakes. My CCW wheels are likely 3-4 lbs lighter per corner than the OEM Z06 wheels! What's more, the smaller diameter tires are also 1-2 lbs lighter than their 19/20" counterparts.

See, life is good, you can win/win : )

In other words (my 2 cents): sell your brakes as a kit, buy StopTech kit front/rear or Z06 irons, shod them with lighter forged wheels, and your suspension will thank you, and your wallet will also likely break even. If you have funds, just keep your OEM for the time you sell your car.