M5 vs. CTS-V Drag Race

[tforth]

Originally Posted by pitfield Aerodynamics might be better and it also has 7 gears.

Apparently the CTS-V has a Cd of 0.31 vs. 0.30 for the E60 M5. Furthermore, there are a number of cars now that have 8-speed trans, and I haven't heard about any of them having this type of 'two-stage' acceleration profile. It's almost like they torque-limit the engine until it's in 5th gear or something.

GTBoard (aka M5/6Board) set up there whole drag sequence to take advantage of this characteristic (i.e. 50-260 km/h).

[RC45]

Originally Posted by tforth Apparently the CTS-V has a Cd of 0.31 vs. 0.30 for the E60 M5. Furthermore, there are a number of cars now that have 8-speed trans, and I haven't heard about any of them having this type of 'two-stage' acceleration profile. It's almost like they torque-limit the engine until it's in 5th gear or something. GTBoard (aka M5/6Board) set up there whole drag sequence to take advantage of this characteristic (i.e. 50-260 km/h).

This is more o a display of gearing than anything else. The M5/M6 drivetrain is setup for optimum acceleration from 0 to top speed. The M cars dont really have a 'cruise gear' - over drive ratio. With 6 gears shorter than 1:1 and a final drive of 3.6 vs the CTS-V's 3.23 the M5 should keep pulling long after the CTS-V settles in to a 0.85 / 3.23 highspeed "cruise".

The one car was designed for legal highjinks on the autobahn, the other for quick dashes to an illegal 140mph and then back to 70 in the fast lane

[tforth]

Originally Posted by RC45 This is more o a display of gearing than anything else. The M5/M6 drivetrain is setup for optimum acceleration from 0 to top speed. The M cars dont really have a 'cruise gear' - over drive ratio. With 6 gears shorter than 1:1 and a final drive of 3.6 vs the CTS-V's 3.23 the M5 should keep pulling long after the CTS-V settles in to a 0.85 / 3.23 highspeed "cruise". The one car was designed for legal highjinks on the autobahn, the other for quick dashes to an illegal 140mph and then back to 70 in the fast lane

OK, that makes sense with the CTS-V, but what about the 550 race? I've seen countless vids (highway runs) where if the other car is close, or just a little faster up to ~120/130mph, the M5 will reel it in and walk away until the limiter triggers.

I have never heard any good reason to explain why this happens.