One other thing to remember about the Z06 is that, while the gears are shorter, it means you're shifting earlier also.
For example, in a 0-100mph run, you may get to 55 in 1st, 80 in 2nd, and make 100 in 3rd. The Z06 may need to shift into 4th to get to 100 (just making up numbers - illustrating that the Z needs to shift more and sooner).
The more important part, however, is torque multiplication over time. Let's say you line up with a Z. You both launch, and he is putting more torque to the wheels than the GTS, and he pulls ahead.. after, say, 200 feet that takes 4 seconds to cover, he's shifting into 2nd where is torque multiplication is 20% less. Now, YOU have more torque at the tire than he does... so for the next 100 feet, you're still in 1st and he's in 2nd... so you're putting more torque down than he is for the next 100 feet and 1.5 seconds. Then you grab 2nd and now he has more again for 100 more feet and 2 more seconds... but 80 feet later he's going into 3rd and again you are still in 2nd putting more torque to the wheels than he is... and so on and so on.
So, in 10 seconds which car can cover more ground and be traveling faster? It's not just about the torque multiplication of the gears, it's also about the RPM limit of the car, the actual gear ratios, the torque curve, and alot of other things. Yes, the Z06 may have more torque multiplication at it's torque peak than the GTS, but we are only at our torque peak for a fraction of a second, meaning it pales in importance to the torque CURVE. If you drew a graph, the GTS may have more torque to the wheels (even with it's lower multiplication) from 1,500RPM to 3,500RPM and the Z has more from 3,500 to 5,000 or something.
It's easy to argue numbers - the Z06 guys love to argue the numbers
- because it takes out alot of the variables in the equation and they focus on one single point about why the Z "has to" be faster.
None of that really matters... back to back, stock vs. stock, equal drivers and conditions, the Viper is the faster car. That's the bottom line. It's been proven in the magazines, it's been proven on the track, and it's been proven on the timeslips.
I'm aware a couple of "good" drivers with intakes have run in the 11's. My friend Greg (who owns a twin turbo Z06) drove my BONE STOCK Viper to an 11.76. This is when the car was BONE stock, meaning no K&N's, no smooth tubes, no special exhaust, no drag radials, no throttle body coolant bypass BS, no cut airbox.. the SAME as it was when it rolled off the factory assembly line. I have never seen a BONE stock Z06 accomplish this. As far as "just about stock" I've run an 11.68, Jamie Furman has gone faster, and Jason Heffner I believe has run 11.5's in his K&N/smoothie Viper. I don't see ANY Z06's even coming close. I've seen a few guys with drag radials running 11's... when it comes right down to it, the MPH tells the speed of the car. The ET is how well you maximized the power potential - most of that is driver, but alot of it is the suspension setup too. No Z06 is EVER going to MPH STOCK than the equivalent Viper.
Having said all of that, they are close enough that a GOOD driver in a Z06 CAN EASILY take out a not-as-good driver in a Viper... but as far as the CARS go, the Viper is simply the faster car, no question. I give all the credit in the world to GM for making the Z06 so close... and all the credit in the world to the Z06 guys taking out Vipers... it warms my heart to know good drivers actualyl RUN their cars and show up the occasional poser in the Viper
. But the cars aren't equal.