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      08-24-2011, 03:57 AM   #195
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Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

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I'll start here and reply to the next (from img) when I have a bit more breathing room with work...

Originally Posted by DLSJ5 View Post
You do make some good points, but I think you're just a bit too confident in your assertions.

So far with boosted E9X M3's, when you look at Vbox results, comparo runs, trap speeds, etc, the DCT is superior in straight line acceleration, that's just the way it is, it appears just about everybody, especially those with actual experience, acknowledge this to be the case.
We agree here, DCT provides improved acceleration, it is due nearly entirely to shift time, not gear ratios differences. We simply disagree about the size of the benefit.

Originally Posted by DLSJ5 View Post
The 6MT and DCT cars in that vid DID make similar WHP on a Dynojet, when comparing different Dynojets it is quite rare that you will get a huge difference in WHP, that's what CF's are for. I do agree that a 6MT with more traction would be a better comparison but for you to overly assert that they aren't making the same whp is rubbish.
There are simply way too many variables here as I have covered. Fact of the matter is very simple. Cars with the same peak hp time and trap (in an apple to apples comparison) at very close to the same numbers, period. If the numbers are radically different but drivers and traction and the like are similar, then THE only logical explanation is a power difference. There is not too much debatable on this point.

Originally Posted by DLSJ5 View Post
You say the DCT is only good for 15-20whp?
If you want to think of a hp equivalent for DCT, based on a stock 414 hp M3, and when looking at 1/4 mi times/trap, yes this is the difference. Both test and simulations back up this claim. In many cases the results are so close that other factors even overcome the differences. Have a look here at this performance "database" of stock M3 performance results.

Originally Posted by DLSJ5 View Post
Then how do you explain a 366whp DCT trapping 116 and a 500+whp Supercharged 6MT trapping 119, same day, same track?
There are only about a dozen explanations. But the essense of it is that it is an apples to oranges comparison where BOTH cars did not each reach there best possible time and trap.

Originally Posted by DLSJ5 View Post
When you take the traction factor out of it -

How do explain the .7 - 1 second difference between supercharged 6MT's and DCT's 60-130, even when the 6MT's are making more power?
Not enough information to make any guesses on this case.

Originally Posted by DLSJ5 View Post
How do you explain the 6MT SC'd Stroker 613whp being .5 -.7s slower than a 570whp and 586whp DCT M3?

How do you explain a DCT making 570whp vs. a 6MT making 590whp, same kit, same dyno on the same day as well produce vastly different results in comparo runs, the DCT was MUCH faster.

How do you explain on the same stretch of road, a Stage 3 6MT @ 640-660whp doing 60-130 in 6.9s vs. a DCT Stage 2 @ 586WHP doing 60-130 in 7 flat and 6.8s, even with 60+whp less the DCT was still faster.
I suppose you can come up with case after case of seeming exceptions to the rules. I am pretty confident that DCT absolutely can not make up a 60 hp defecit in a 60-130 run. I will run some more sims to look into this case.

Also do note: I ran quite a few simulations to form/validate/back up some of the claims I made in my prior post. The basics I did long ago but added some work right when posting. I will have to put those together and also reply to the simulation based post response from img.

Perhaps we should take this offline to another topic? I think it is a great topic for a totally separate thread. I'm a huge proponent of DCT, always have been. However, there is simply too much being ascribed to it here. It is not magic, it just shifts fast. We should all not ruin your cool engine build thread with this useful debate/discussion.
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK |
| Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors |
| Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels |
| XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit |