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      10-23-2013, 06:36 PM   #17
Tom C
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Quote:
Originally Posted by turbo8765 View Post
The AWD improves the ET not the trap. The Benz will have a better 0-60mph and 60' time due to awd.

The DCT contributes to both a faster ET and trap for a given power to weight compared to an inferior transmission. This is best illustrated by comparing a given car available with a DCT and non-DCT transmission i.e. the e92 M3.

The AWD contributes primarily to a lower ET when compared to RWD (assuming street tires) and contributes minimally if at all to a higher trap speed. This is best illustrated by comparing a car available in both rwd and awd, there are quite a few.

"Finicky on a dyno". That's what you say when you don't know much about dyno's and you're suprised by the observed result i.e. have no other explanation.
You are failing to grasp what I am saying about AWD. Yes if the same car has AWD and the same engine, transmission, etc, it should put down less power at the wheels. In this instance we are talking about the net result of the E63 S putting down 540+awhp. So this is post parasitic loss. If we were talking about crank hp, it would be a different story.

The AWD DOES help improve trap speeds as well as ETs. The more efficient you are during the quarter mile run, especially early on, the more effective distance you are allowing yourself to build speed. A good example is the Nissan GT-R running with and without launch control. The LC runs (in every test I have seen) always had a higher trap speed than the without LC runs. The LC allows the car to be more effificient off the line and allows more of the "track" to put down the power and hence the higher trap speed. The reason you see lower trap speeds for AWD cars when compared to the same exact model is because of the additional weight of the AWD system and the parasitic loss. If the AWD car weighs the same and has the same exact wheel hp and transmission, the AWD will trap higher.

Having had a GT-R and taken it to a drag strip and collecting vbox data for it, I saw the advantages of having both AWD and the DCT.

Your comment about "finicky dynos" shows your ignorance about dynoing the M5. It is widely known that the M5 has some issues on the dyno with the ECU pulling timing because of improper air speed, front wheels not moving at the same speed as rears and various other "finicky" things that prevent "good" #'s. that isn't to say that dyno operators can't get a good dyno #, but they have to be aware of these idosyncracies and address them.

Last edited by Tom C; 10-23-2013 at 07:28 PM..
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