10.85 129.50 New Best for a Bone-stock C6Z06 on DOT Drag Radials
I grew up relishing the stories on Zora’s specially prepared ZL1 Corvette running in the 10.90s on slicks. Love those stories. And it’s almost hard to imagine that 35 years later, a showroom stock Corvette, albeit a 2006 Z06, with no change to the car other than using DOT drag radial tires could eclipse the times posted by that fabled ZL1. But it happened today at Maryland International Raceway in Budds Creek, Maryland.
On my first pass of the day, after an hour-long cool-down and change of rear tires to the BFGs, I ran a clean pass with the type of launch and 1-2 shift I’ve been looking for. Here are the splits:
60'........1.679 3650 launch rpm with a fast clutch release and fast throttle squeeze
1000'.....9.114 1320'...10.856 129.50
Density Altitude at the time of the pass was negative 850 feet on my TAG weather station. Air temperature was 51 degrees. Barometer was excellent and humidity was low.
Track surface temperature was 60 degrees, kissed sweetly by full sun.
Soon after returning to the pits, amid a mild celebration, I was visited by a track official on a motor-bike for a discussion of the safety equipment in my car. He noted it was apparent from the tower that my UnderArmor compression top wasn’t a fire-jacket. And his check inside the car found no roll-bar. He complimented the pass and I took the hint, agreeing to slow down. In keeping with that pledge, I made one more pass. After bogging the launch to comply with guidance, was then somehow unable to keep from driving the rest of the pass…well…fast. I picked up the slip, 11.03 129.22 1.80. And that was it for the day.
Special thanks to dgdoc, Steve, and Bill for their moral support and assistance crewing the car, today.
For the record, nothing has been changed on my car since delivery other than the driver’s experience. ECU/PCM is stock. Air filter is original. Nothing after-market at all.
I did dismount the stock rears and strap on three-year-old BFG 315.35.17 DRs, graciously lent to me by Dick Link. These tires are perfect for the C6Z in that they don’t overwhelm the finicky LS7 clutch. And, if properly heated, they can provide excellent traction. I also raised the stock front tires to 40 psi; above that the DIC starts nagging on start-up.
If anyone wishes to draw a distinction that “bone stock” must include “stock tires,” he/she may wish to revisit scores of threads I’ve started over the past six years describing adventures at the drag strip with bone-stock Z06s either on (1) stock tires or (2) drag radials. I’m always clear about the tires on the car any particular day, in the thread title.
On shift points, as alway, I tried to make each shift as close to the limiter as possible without kissing it. On this 10.85 pass my shift points were good, at 7000 except for the 2-3 which occurred at about 6700. So, was not a perfect pass.
As for powershifting, I eased the throttle on the 1-2 and 2-3 but did powershift the 3-4. My experience has shown that you can shift fast while still easing the throttle. Takes practice.
I’ve written frequently that it takes 30-50 passes for a driver to approach his lower limit in a new plaform. That 10.85 was my 52d pass in the car.
I have some video footage of uncertain quality (new guy on the camera) and some audio files of the exhaust on the pass, plus a spreadsheet with split/incremental analysis. I’ll work on these over the weekend and edit them into this post. I am posting the slip of this record pass, certified by an MIR tower official.
I close by offering my continued appreciation to the Corvette Team and extended family for the C6Z06, a truly amazing car and the new legend. And somehow I know, Zora is pleased.
Edit (061105): I've added a thumb of my normal spreadsheet analysis of the 10.85 pass at a negative DA against my 11.06 at a positive DA last week. It clearly shows the small contribution made by the better DA. But improved driving in the first 330' is the main factor that made the pass memorable.
Edit (061128): Added a link to the sound file of the 10.85 pass, as recorded at the exhaust. Easy to hear
(1) bog on launch, inevitable with the LS7 clutch
(2) speed of shifts, which takes practice and
(3) the urgent rhythm of the LS7 at wide-open-throttle.
Best to all,
Last edited by Ranger; 07-01-2007 at 07:53 AM.
Reason: Permanent links to documentation