C6 Z06 vs. C6R Comparison

[DJWorm]

Below is a link to a good article citing GM Racing's Steve Wesoloski, Road Racing Group Manager comparing the C6 Z06 with the C6R.

Things to remember:
- C6 Z06 uses technology derived from C5R not C6R
- C6R is based on C6 homologation, and is an evolution in design from the C5R.
- C6R technology will show up on the C7 & C7(Z06)?

Some discrepeancies I found in the article.
- a statement refering to previous big block 427 racing engines then a statement referring to current 427 engines stated "production engines are precision ground and race engines are precision bored and are linerless."
I know that both current 427 production and race engines are precision CNC bored with deck plates and precision honed. Race C5R & C6R engines need to be finish honed. Both have liners.
Some late 1970's Can Am Aluminum big block were Silicon impregnated and were run linerless. I doubt that current production or race aluminum blocks are run without iron liners.
- The article noted improvements in the valvetrain and noted among other things that Titanium push rods and Titanium Valve springs were used in the new LS7. I know that the LS7 has upgraded and better pushrods and bigger valve springs but I doubt they are Titanium.

Summary Comparison
- C6R has NEW Moton 4 way adjustable Coil Overs upgraded from the JRZ and Penske 3 way adjustables of the C5R vs. the composite transverse monoleaf C6 Z06 spring(s)
- 2450#'s vs. 3180#'s
- C6R is 25 mm wider than C6 Z06 and must not be more than 100mm wider than C6
- C6R suspension attatchment points may vary no more than 25mm within a sphere of stock points
- C6R uses custom tubular adjustable Steel A-Arms vs Aluminum cast on C6 Z06 and modified cast on C5R
- C6R uses custom tubular Steel subframe "K-member" instead of cast magnesium or cast Aluminum sub frame/engine cradle
- C6R uses C6 derived hydroformed Steel frame vs C6 Z06 hydroformed Aluminum frame
- C6R uses a CF/Nomex/CF composite sandwich floorboard instead of the CF/Balsa/CF floorboard for fire safety
- Like C5R, C6R uses custom CNC ported heads with smaller combustion chambers (30-38 cc), higher CR, Jesel shaft mount roller rockers with roller tips

Some very suprising facts are that the C6R's Rev limiter is set at 6,200 RPM and rarely sees constant use over 5,000 RPM. It is built for high torque using a short duration/ high lift cam. This is probably due to the 31.8mm restrictor plates. They could have used larger restrictor plates but at an increased +2,600# weight. The car is faster when lighter even with the increased restriction.

What's really suprising is the engine produces 590 HP and if unrestricted and fully cammed will produCe 800 HP normally aspirated !!!! This hints at the potential of the production LS7 engine when properly modified.

http://www.machinedesign.com/ASP/vie...Auto&catId=382

[Red Kelly]

Don, do you eat this technical stuff for breakfast, lunch and dinner or what

Great article, thanks for sharing

[DJWorm]

....slightly off topic article on a NEW 800 MPH "car".

http://www.machinedesign.com/ASP/vie...TISSUE&catId=3

[Zippy]

Good info DJ! Thanks for sharing with everyone.

Steve Wesoloski was recently promoted within GM, and currently in charge of several areas of GM racing.

I had the opportunity to introduce Steve for his seminar at our Z06 Fest this past July. His topic? "Engineering Transfer Between the C6R and C6 Z06." Great guy, and brilliant Engineer.

[Red Kelly]

Originally Posted by DJWorm

....slightly off topic article on a NEW 800 MPH "car".

http://www.machinedesign.com/ASP/vie...TISSUE&catId=3

"generates about 18,200 lb of thrust or 42,5000 hp when using an afterburner". That's one helluva set up for a grocery getter.

[DavidNJ]

Thanks for the link. Overall, it sounds like a high-end asphalt late model stock car with an all CF body (stock car would have only the roof, hood and rear deck) and IRS.

This is my favorite quote, that emphasizes a point on many threads in this forum:

Despite a weight penalty, race cars use steel rails as opposed to aluminum for production Z06s. The use of steel simplifies joining of the 4130-steel roll cage to the rails. It is important to weld the triangulated-truss roll cage "into" the frame rails because the chassis derives much of its stiffness from the arrangement. Aluminum-to-steel joining methods simply don't give the same level of integrity as welded sections.