To all those interested in the OT performance advantage of M-DCT vs. 6MT and in the very closely related issue of shift times:
http://www.m3post.com/forums/showthr...=582295&page=4
A bit tough to track the main thrusts from the players in that debate (myself included of course). In short some of the supercharged M3 drag racer guys felt that M-DCT could be good for an equivalent 50 hp and 10 mph trap speed advantage in the 1/4 mi. I actually argued strongly against that. However, again, it depends on exactly which contest you are trying to compare, 0-60, 60-130, 1/4 mi. time or trap, time to speed, time to distance, etc. In that discussion I actually began using some 0.2 (200 ms shift times). The drag racer guys insist from vbox data that 0.6 seconds is much more realistic. There is no one right answer here but I am fairly convinced most non-pro folks cannot consistently shift a production 6MT E9X M3 car in 0.2 seconds, certainly not without powershifting.
To ascribe an equivalent power gain due to M-DCT is absolutely reasonable however, there is no one single best number for it. Bruce's rough estimate above seems to work out to 15 hp (3.6%). An absolutely critical factor in this is the shift time difference. The best estimates for the M-DCT are in the 50-100 ms range. My prior quick "back of the envelope" calculation showing a 60 hp advantage was not supposed to represent my best guess for the M-DCT advantage, just to show that there is one and how large it might be.
Here is a reasonably large performance database of magazine test results:
http://www.m3post.com/forums/showthr...=70737&page=15
Other than a single outlier in 2 contests the M-DCT cars are overall faster than the 6MT cars in the quarter mile and in many other contests.
The best way too look at this is actually physics based simulations. The formulae Bruce and I have used above are decent approximations for some very quick "back of the envelope estimates". Better than those are a real simulator which is ideal for this type of problem, both because it captures the physics but also, very importantly because it holds ALL variables absolutely constant between the runs (such as temperature, tires, launch, weight, shift times (and other driver effects), parasitic losses, etc.). Below are simulations for a stock E92 M3 M-DCT vs. 4 different 6MT cars, equal power and then +20 hp, +40 hp and +60 hp.
These results are based on a 50 ms M-DCT shift time and 400 ms 6MT shift time. They indicate, that
depending on the contest, the M-DCT is good for somewhere between an equivalent 20-50 hp over the 6MT car. If you (or some theoretical you) can consistently shift in 200 ms this equivalent hp advantage figure will probably drop to about VERY ROUGHLY about half of this. I certainly could have run those simulations, but felt
a bit lazy.
Anyone should recall this basic fact - it take a lot of hp to make relatively small changes in ETs. This along with shift time savings for the M-DCT is the "equivalent hp" idea and it takes quite a bit of it to account for relatively small time savings.
I think am truly done with this OT debate here. Hopefully, some fellow members can continue my effort in leading the thirsty to the river on this particular point.