Big difference in trap speed in LS3 vs L99?
 

http://www.motortrend.com/roadtests/...test_data.html

Seems like there is a huge difference in trap speed between the LS3 and L99 (111.0 mph vs. 107.5). There is only a 1.7 mph diff between the auto and stick versions of the V6. Is this a fluke or is the automatic and L99 reduced redline that much big of a drag on top end? Seems like if I remember correctly, past F-Bodies only had maybe a 2 mph difference in trap speed.

Automatic trannies are heavy. They are giant hydraulic pumps vs a gear box with heavy oil.

Would be nice if everything on earth was perfect and the same or better. But it's a luxury item that not really designed to be the best performance option.

Actually that link I posted shows the auto as lighter than the manual. But in other specs I've seen, the manual was lighter, by only about 50 lbs. though.

Don't forget the hp difference, it's pretty big. That alone is ~2.5 mph. And then the weight (50lbs) is another ~.5 mph. Normally a conventional 4 spd auto would result in another 2-3 mph slower, but the 6 speed auto is geared pretty aggressively so it get's some of the mph back.

Unless of course, you are drag racing.

:word: I'll go with this answer as well ...

Crowley

All these things are just generalities right now...basing fact on a few magazine tests with test mule cars (a small sample size at that) will not give you absolute truth. I would say the auto is several mph slower, but is it almost 4mph slower...time will tell. I can tell you this though, a A6 with a small stall will be quicker AND easier on the drivetrain the vast majority of the time whether on the street or track. Granted it will not be as good for road course events, but as far as drag racing goes, it will end up being a very capable setup.

Once folks get rolling with the VVT cam research, I think you will see the playing field start to even up on power output (once AFM is removed). Even though the peak numbers may continue to be lower on the L99 the AUC power produced by the VVT technology along with a stall converter will create a vehicle that will ET awesome in the 1/4, albeit at likely a lower mph. Remember, peak #'s don't necessarily mean it will be quicker, having a large AUC with a flat TQ curve, means these heavy pigs will get rolling quick...factor in the STR of the converter and they'll leave the line in a hurry on DR's. A 6sp manual will do it also, but you'll have to clutch dump it to 60' with the stalled auto and that is neither clutch friendly nor rear end friendly.

I'd expect about a 4 mph difference between the M6/LS3 and the A6/L99. Considering the M6 has 26 more HP to play with at the flywheel, that's worth 2, maybe 3 MPH right there. Plus an automatic typically has more losses in the tranny and along the drivetrain, I'd say autos often dyno ~10 HP lower than manuals for the same rated flywheel engine power. So the automatic L99 is starting with less HP to begin with, and getting a lower percentage of it to the back wheels.