Halltech

GM portrays the image that they are into gram weight savings on the Cadilllac CTS-VSport*. Why then did GM decide to back to the past with more SMC and not with lightweight carbon fiber? Compare the ZR1 to the C7Z06 and the new C7Z has lost the carbon fiber front fenders. SMC is around 50% heavier than carbon fiber.

I am glad that they left most of the car SMC so that another 100lbs can be shaved off by the aftermarket. Not Halltech, but someone.

We found that our GT2 hood was a great idea, selling around 38 hoods, but the roof/b-pillar, deck (Katech's product), rear quarters never really took off, even though our pricing was 50% of the OEM replacement parts (hood/roof/pillar). Other than the race types, folks seem content and happy with heft.

A true supercar does not come in SMC with a carbon roof and dash.

*http://www.caranddriver.com/reviews/...-6-test-review

jvp

What do we want the Z06 to cost? $100k fully loaded, or $120K fully loaded? While I agree that it'd be nice to shave a little mass from the front using CF fenders and liners like last generation, how much money would that add to the car's bottom line?

I don't know those numbers. I bet GM does, though, and they decided they didn't need the loss in mass and potential sales due to the higher price.

Engage brain fully before posting, please folks.

chuntington101

Pure carbon would add a lot of cost to the car. however there are more and more materials becoming even available that are nearly as light as carbon but at a reduced cost.

B Stead

Carbon fiber works best where it is used structurally. For instance the new BMW i3 has a carbon fiber tub and so that includes rocker panels and front and rear bulkheads. Then those front and rear bulkheads hold metal frame channels. Basically, the middle of the chassis is carbon fiber while the ends of the chassis are metal.

A carbon fiber fender can be crunched in an accident that doesn't even touch the frame channels. And so SMC is less expensive to replace.

Get weight off the C7 by removing the cylinder de-activation and then going to a lightweight stainless-steel exhaust system.

Another idea would be Gorilla glass for the windshields. Gorilla glass doesn't scratch like plexiglass.

The BBS RS-GT wheels save weight but are only available in 18 x 9 and 19 x 10.5 .

And a 21 pound Braille battery would save a lot of weight. Those are AGM batteries
.

acrace

While there is still a lot of SMC material on the C7/Z06, it's not quite the same SMC. Usage of nano clay and glass spheres as a partial filler/reinforcement and advances in liquid compression molding enabled density reduction of the SMC.

On the Stingray, the exterior panels (class A) saw approx a 20% density reduction. C6 used SMC compounds in the 1.8 to 1.9 specific gravity range, whereas the C7 uses SMC compounds in the 1.5 to 1.6 s.g. range.

For the structural components (such as the rear tub assembly and various fender reinforcements), s.g. for C6 components ranged from 1.4 to 1.9, whereas C7 components are in the 1.09 to 1.2 range.

There was a pretty good SAE webinar early last year on the improvements in SMC material technology, given by the GM body structures composites lead engineer. If you're interested, I can see if I can find a link, and if it's still active.

Z06Ronald

I agree with you, Jim. I was also highly surprised that the hood and the roof are the only CF body parts on the C7 Z06 and that all others are SMC (not counting aerodynamic parts).
Maybe it's an indication that there's still something even more spectacular on the horizon than the Z06, despite GM's denial of all rumors about a C7 ZR1. Time will tell.
Nonetheless I can't but LOVE the new Z06!

PS: in case you have any CF roof panels or CF rear quarter panels left for the C6 Z06, I'm interested! I can't find them on the website any longer.

Halltech

Didn't seem to matter on the C6Z06.

To answer your question, we sell our carbon fiber hand made rear quarters for $900 each ready to paint. The mold was taken off the stock SMC parts. Rear Deck and Lexan window from Katech $2999; Roof and B-pillar from Halltech $1900; GM can make these parts much cheaper than we can.

Going to front carbon fenders would increase the cost maybe $800, so if that breaks your bank, you could stick with the base car, or GM could have carbon fiber options, like they do with the dash.

The base Z06 without the Z07 option will be around $90,000, and just over $100 with the Z07 package (guess)

Halltech

They can deny whatever they want. The ZR1 replacement will be the next Gen model. It will be super expensive, and have surprises that will shake the industry.

Halltech

Good information from a GM engineer. Thanks.

I was at the Dave McClellan SAE seminar in Wisconsin last year where they were supposedly introducing the C7 Stingray, and they had a slide show with a few pictures! Great to meet Dave though.

It is still not carbon fiber. Plasan has the molds, so why not make the body parts in carbon fiber and let folks purchase them optionally or through GM? The Z07 package is what, $8,000 add on? The carbon option could be a huge hit for those looking for the ultimate track car.

Halltech

I agree with most of what you are saying.

We took our 2008 Z06 and reduced the weight to 2777lbs and still have a full interior, a/c and it looks pretty stock, except for the carbon fiber CR-9s by Carbon Revolution.

Z06Ronald

I heard - I believe it was Tadge - on one of the many videos that I've watched, that titanium was considered, but rejected because it was cost prohibitive.
It wouldn't surprise me to see an Akrapovic cat back Ti system any time soon though.

Carbon Revolution will (almost certainly) release their CR-9 wheels in 19"x10" and 20"x12" this year.

I agree on the Braille battery (or other brands).

Personally I would like to see Chevy offering a sort of cookbook, from which a prospective customer who is willing and able to pay the price can select a myriad of premium parts, under warranty.

Halltech

Are you implying that Halltech does not think about our posts?

Asking a question related to the build of the new C7Z06 does not seem to me to imply that there is no thought behind it. If GM's goal is moving the game forward, that would seem to me to include achievements of builds going back 8 years in the new platform, not removing them for base car staples.

There are so many improvements with this car, this one area can easily be overlooked, but it is worth mentioning in a discussion, wouldn't you agree?

Since I have been a member of the forum since the beginning, and think Corvettes every day, every minute, I would say my brain is engaged pretty much full time.

Halltech

19X10.5" 20X12.5 are the sizes they are looking at. Halltech has been involved in the Corvette line development for CR. We run their 19X8.5s and 19X12s on our Ultralight Z06, and have stopping power like you would not believe with 235s on the front. John Heinricy, Jason Harding, and Jim Painter all ageed that the 235s were every bit a good in turns and stopping power as the 285s on heavier wheels. You would not believe where the CR-9s will show up.

B Stead

It seems like carbon fiber used to be wrapped around or laid over cores but now it's made more like injection molding or SMC. That could explain the increasing usage:

http://www.quantumcomposites.com/pdf...ation-2011.pdf

Z06Ronald

Still available? I just looked on your website, I can't find them any longer.

jvp

Perhaps, but finishing it with a snipe at GM:

isn't very thoughtful nor constructive.

You haven't...

As a Supporting Vendor, you have a certain amount of protected status here on the forum. Given that, I'm disengaging.

Z06Ronald

Thank you for sharing this link.

acrace

Just to make sure that there's no misunderstanding . . . I'm not a GM engineer (although I know quite a few). The info in my post (post #5 in this thread) are from notes I took from the SAE webinar where the GM body structures composite lead engineer presented.

Plasan doesn't have the SMC molds; they produce only the carbon fiber parts. Most of the structural SMC parts are done by MFG and the exterior SMC parts are done by Magna and Continental Structural Plastics.

The process that Plasan developed along with part thickness differences between SMC and carbon fiber would require new tooling.

And I would suspect additional equipment; Plasan's presses as used in their Walker, MI facility are custom built to Plasan's requirements and are not built by a traditional press manufacturer. If you ever have the opportunity to engage Plasan's CTO in a technical conference, Gary's got a lot of really interesting stuff, in how Plasan developed technologies to greatly reduce total cycle time for carbon part manufacturing.

acrace

The "forged composite" technology co-developed by Lamborghini and Callaway (the golf club company) isn't suitable for class A exterior body panels. That's why the demonstrator parts on the Lamborghini are suspension arms and the tub component. Also, Callaway uses the forged composite technology in some of their RAZR golf club heads, as a replacement for titanium.

It is a cool technology, and opens up the ability to manufacture parts with details as commonly found in injection molding.

The material is manufactured by Quantum Composites in Bay City, Michigan (who hosted the link). My previous boss at my current employer is now their general manager. This link reminds me . . . I owe him lunch

adamgl

Lol! I think you have earned the right to state your opinion. You have one of the baddest Z06's on the planet.

My biggest problem with the base C7 and C7 Z06 is too much weight.

I wish GM would had you guys do some "consulting" on the C7 base and Z06, and they would have came out better and lighter.