First magazine comparison between MT and DCT

[T Bone]

Originally Posted by jworms

how are you arriving at that considering the facts presented in this thread? or was there somewhere in this thread that discounted this reviewers numbers achieved with both cars?

Pretty simple.

With MDCT, you cannot use brake stand or clutch dump like a manual tranny.

Using my experience with the M5 / M6, even the most heavily modded cars (without nitrous) has got down to just below 12.

[T Bone]

Originally Posted by footie

I agree with TB that more power would be required, to break the 12 seconds barrier would require something special and more than a trick gearbox.

Yes, in a rare moment of agreement...I agree.

The power required to hit 11s then 10s is not linear. I believe it is exponetial.

[jworms]

Originally Posted by T Bone

Pretty simple.

With MDCT, you cannot use brake stand or clutch dump like a manual tranny.

Using my experience with the M5 / M6, even the most heavily modded cars (without nitrous) has got down to just below 12.

so the M-DKG car is not 1.1 seconds faster to 200km/h than the 6MT like the magazine states? i just want to be clear that we are not going to acknowledge this article's data.

[phoenixbmwlife]

Originally Posted by footie

Not a dragstrip guy so apologize if what I say sound silly but surely trap speed doesn't always relate to actual time taken to cross the line. So though the M-DCT car will reach a higher speed in that 1/4mile, it actual time might only improve by say 0.2~3 at best.

Does this sound logical.

Well I agree with what you said about trap speed however I never mentioned anything about the M3's trap speed. Just that 12.5 was accomplished already by a manual. Mind you I'm not saying its an easy task to get a time under 12 seconds, but with the right conditions, tires, temperature, fuel, weight, etc., and a strong breeze in its rear I think its possible.

At 100+mph .5 seconds might be a cars length or a little less which is plausible for MDCT. Again with the right conditions. JMO

[T Bone]

Originally Posted by jworms

so the M-DKG car is not 1.1 seconds faster to 200km/h than the 6MT like the magazine states? i just want to be clear that we are not going to acknowledge this article's data.

We were talking about the quarter mile and you are looking at 110 mph not 200 kph.

If you are talking about about the 0-200 kph runs then absolutely the MDCT is significantly faster. Someone will be able to calculate how further ahead a MDCT car would be when it crosses 200 kph versus a 6MT car.

[enigma]

Originally Posted by southlight

That's the Continental 'Contidrome' handling track. 3800m, 11 turns, bottom of this pic:




Best regards, south

This looks like a very handling intensive track without the long straights some other tracks have. Therefore with limited chances to use its acceleration advantage on this course the difference would have been reduced.

Laguna Seca, Monza, or Thunderhill would show very different results.

[T Bone]

Originally Posted by K3N R3D

Well I agree with what you said about trap speed however I never mentioned anything about the M3's trap speed. Just that 12.5 was accomplished already by a manual. Mind you I'm not saying its an easy task to get a time under 12 seconds, but with the right conditions, tires, temperature, fuel, weight, etc., and a strong breeze in its rear I think its possible.

At 100+mph .5 seconds might be a cars length or a little less which is plausible for MDCT. Again with the right conditions. JMO

Wanna wager??

I bet that a stock M3 MDCT will not go faster than 12.00. Deal?

[phoenixbmwlife]

Originally Posted by T Bone

Wanna wager??

I bet that a stock M3 MDCT will not go faster than 12.00. Deal?

Wager? Buddie I'm just giving my opinion here.

[T Bone]

Originally Posted by K3N R3D

Wager? Buddie I'm just giving my opinion here.

Where's the spirit? A little friendly wager to back opinion never hurt anyone.

Opinions always sharpen when there are consequences behind them

[SteelTorque]

Originally Posted by jworms

how are you arriving at that considering the facts presented in this thread? or was there somewhere in this thread that discounted this reviewers numbers achieved with both cars?




i'm not even looking at what the M3 might trap, i'm only looking at the ET (elapsed time) difference between the 6MT and M-DKG. from what i can tell in the first post, the M-DKG equipped car is a bit over a second faster than the 6MT car for 0-200km/h. unless, like i mentioned above, there is some reason to not acknowledge these results?

i was even being fairly conservative and not using the reported 1.1 second difference between the two. the M-DKG car would only need .6 of a second to get into the 11s, that's only around half of what the M-DKG car reportedly ran compared to the 6MT car.

Have you even been at the drag strip? it doesn't sound like it, because then you knew that time-to-distance and time-to-speed are two very different things.
sorry if I sound like and ass.

Second, I don't think the M3 is an everyday mid second car, maybe under special circumstances but to grab what one or two magazines with professional drivers accomplished and used that to bench race is pretty ridiculous.

[jworms]

Originally Posted by T Bone

We were talking about the quarter mile and you are looking at 110 mph not 200 kph.

If you are talking about about the 0-200 kph runs then absolutely the MDCT is significantly faster. Someone will be able to calculate how further ahead a MDCT car would be when it crosses 200 kph versus a 6MT car.

huh?

the article states that the M-DKG M3 did 0-200km/h (0-124mph) in 15.2, while the 6MT car did the same 0-200km/h (0-124mph) in 16.3. that is a 1.1 second difference in ET which i can probably safely assume is mostly not taking place towards the end of the run due to the majority of the gear changing taking place earlier on.

so, we have a 1.1 second difference between the two from 0 to 124mph.

so, like i mentioned before, if we go way conservative and say that the M-DKG car will only produce a .6 boost in performance (slightly over half of the 1.1 second boost reported in the article) for a 1/4 mile run, then we have an 11 second run when compared to the best known ET from a 6MT car: 12.5.

[T Bone]

Originally Posted by jworms

huh?

the article states that the M-DKG M3 did 0-200km/h (0-124mph) in 15.2, while the 6MT car did the same 0-200km/h (0-124mph) in 16.3. that is a 1.1 second difference in ET which i can probably safely assume is mostly not taking place towards the end of the run due to the majority of the gear changing taking place earlier on.

so, we have a 1.1 second difference between the two from 0 to 124mph.

so, like i mentioned before, if we go way conservative and say that the M-DKG car will only produce a .6 boost in performance (slightly over half of the 1.1 second boost reported in the article) for a 1/4 mile run, then we have an 11 second run when compared to the best known ET from a 6MT car: 12.5.

I understand what you are thinking and writing but it is not how the world works. Acceleration is not linear. A top fuel dragster has 7000 hp and does a quartermile in 4.5 seconds.

[jworms]

Originally Posted by SteelTorque

Have you even been at the drag strip? it doesn't sound like it, because then you knew that time-to-distance and time-to-speed are two very different things.
sorry if I sound like and ass.

Second, I don't think the M3 is a everyday mid second car, maybe under special circumstances but to grab what one or two magazines with professional drivers accomplished and used that to bench race it's pretty ridiculous.

yes, i have quite a bit of drag strip experience and i do understand the concept of time-to-distance vs time-to-speed. so let me ask you this: if two cars are ending their 1/4 mile runs at the same speed, but one gets to that speed in .6 seconds less time, what will that translate to in reported ET for both cars on their timeslips?

the 6MT M3 is already trapping as high as the ~115mph range which isn't really close to 200km/h (124mph) at all, but trap is an average speed over the last section of the drag strip, so the M3 will actually be crossing the line at a mph higher than what's reported for trap speed, getting that much closer to the 200km/h (124mph) mark. i also stated that the difference in performance is most likely not coming coming from the last stretch of the run, but even if it is, i also went the conservative route and used .6 seconds as the performance difference just in case that last 1/2 second of performance difference is coming in at the last part of the 0-200km/h run.

[LandShark]

great news! I'm glad to wait out for the M-DCT!!

[JEllis]

Awesome... honestly never doubted that the MDCT would be quicker...

[swamp2]

jworms: It is extremely unlikely/impossible that the M-DCT M3 will break into the 11's. The differences in time to speed do not translate to the differences in time to distance. Also the gains by the M-DCT also rise and fall throughout a run. For instance if a particular measurement point is right after a MT shift then the difference can be larger. Lastly some times the MT is in a lower gear accelerating harder than the M-DCT which has already shifted to the next gear.

Expect about a 1 sec difference to 120 mph (per acutal tests and simulation as well) but only 0.2 - 0.4s in the 1/4 mi.

[enigma]

Originally Posted by swamp2

jworms: It is extremely unlikely/impossible that the M-DCT M3 will break into the 11's.

I agree its extremely unlikely. However, never say never. On the right day with all the stars aligned and a really sticky launch surface it might happen. However, this will be the exception, not the rule. Just like the guys that got a 12.7 out of a stock E46.

[jworms]

Originally Posted by swamp2

jworms: It is extremely unlikely/impossible that the M-DCT M3 will break into the 11's. The differences in time to speed do not translate to the differences in time to distance. Also the gains by the M-DCT also rise and fall throughout a run. For instance if a particular measurement point is right after a MT shift then the difference can be larger. Lastly some times the MT is in a lower gear accelerating harder than the M-DCT which has already shifted to the next gear.

Expect about a 1 sec difference to 120 mph (per acutal tests and simulation as well) but only 0.2 - 0.4s in the 1/4 mi.

i agree that gearing will definitely play a part in what ETs will be pulled. i'm also a firm believer that the public will see better results than what the magazines/reviewers will get just like they did with the E36 M3 and the E46 M3 and, if nothing else, i think with just the addition of drag radials to an M-DKG car we'll see 11 second runs.

[swamp2]

T Bone: The M-DCT tops out at just a bit over 170 mph in 6th. Although a bit odd and seemingly contradictory I agree with BMW using 7th for an economy gear. I think enigma and e36jakeo said it but M-DCT packs in better and closer ratios in 6 gears to what the MT does in 5 (top speed in MT in 5th is just shy of 170). You get better performance all the way up to this speed point. How often will you or anyone go faster? Using 7th as an overdrive gear is fine with me. Lastly although it takes a bit longer to get to Vmax the value of Vmax is almost identical.

[T Bone]

Originally Posted by swamp2

T Bone: The M-DCT tops out at just a bit over 170 mph in 6th. Although a bit odd and seemingly contradictory I agree with BMW using 7th for an economy gear. I think enigma and e36jakeo said it but M-DCT packs in better and closer ratios in 6 gears to what the MT does in 5 (top speed in MT in 5th is just shy of 170). You get better performance all the way up to this speed point. How often will you or anyone go faster? Using 7th as an overdrive gear is fine with me. Lastly although it takes a bit longer to get to Vmax the value of Vmax is almost identical.

I understand BMW's choices but I just like it. I guess I am a bit of a purist. FOr the same reasons, I hate the Z06 gear box. 5 fun gears and a useless fuel economy 6th gear.

I also don't like the linear torque curve the M3 motor has.

[enigma]

Originally Posted by T Bone

I understand BMW's choices but I just like it. I guess I am a bit of a purist. FOr the same reasons, I hate the Z06 gear box. 5 fun gears and a useless fuel economy 6th gear.

I also don't like the linear torque curve the M3 motor has.

As a track guy I can tell you its possible to have too many gears. There is some point where the distraction of the extra shifts becomes more of a performance issue than any benifit they provide (unless you use an automatic mode like F1 did for a while).

I do agree with you on the power band. Flat torque bands are way overrated. They should have tuned for high rpm power and been willing to sacrifice some of the lower range torque to get it. However, as you have seen here, the public perception is "torque matters" and you have people who think things like the 335 will be faster because it has more torque. Stupid, but true. However, the have to deal with this market reality.

[footie]

Originally Posted by swamp2

Expect about a 1 sec difference to 120 mph (per acutal tests and simulation as well) but only 0.2 - 0.4s in the 1/4 mi.

Originally Posted by footie

So though the M-DCT car will reach a higher speed in that 1/4mile, it actual time might only improve by say 0.2~3 at best.

Well what do you know, me and swampie are actually agreeing on something. Phone Reuters.