CarTest results and comparisons vs. MB AMG

[southlight]

Originally Posted by swamp2

Max speed in gears according to my calculations are (km/h):
68
117
232
276
317 (if gear limited, but likely not, drag limited)

I think the problem is simply the fidelity of the graph routines in the software. Looks to me from the graph like 0-62 for the 6MT is 5.0, actual figure from the table report is 4.7. I just don't think you can see 5% or so on the graphs, even the traces are a bit too wide for that. The graphs are better just to see relative performance. Agree the graphing part of the softeware likely could be improved a bit as well...

Here are the numbers in metric, tabular form:

OK, now I realized where's the problem:
The software calculates the wrong tire circumference. It does the math correct, but doesn't care about the tolerances. As always there's a european organisation that has set this standards (ETRTO):

Without tolerances: [(265 x 0.4) x 2 + (18 x 2.54)] * pi = 2.10 m
But according to the ETRTO standards the circumference for this dimension is only 2.04 m! My calculation is based on a calculator of a good german forum site (m-forum.de) which calculates with an average between a new and an old tire. This calculates with a circumference of 2.02 m. The dates are the following:

1st: 65.3 km/h (40.6 mph)
2nd: 111.7 km/h (69.4 mph)
3rd: 167.3 km/h (103.9 mph)
4th: 221.3 km/h (137.5 mph)
5th: 264.7 km/h (164.5 mph)
6th: 303.6 km/h (188.6 mph)

Don't know why the test software doesn't consider this tolerances!? Maybe this is another european specific topic. Don't know how the T&RA standards are. I will check that later if nobody else does...

Best regards, south

EDIT: Now I checked the US Michelin site: There it says "Rolling circumference can be calculated as follows: 63,360 divided by revolutions pre mile = rolling circumference in inches:
For the 265/40ZR18 PS2 Michelin states 790 revs per mile --> 63,360 / 790 = 80.202 inches = 2.037 m.
So it's the same standard for the US. The circumference calculated by the software is too big...

[Garrett]

Originally Posted by swamp2

It is easy to be nice and polite when you want something isn't it?

Give me the peak hp, rpm at peak hp, peak tq and rpm at peak tq and I will do some runs...

BMW 335 w/PROcede V2.0:

Peak HP: 410hp @ 5,500rpm
Peak TQ: 420ft-lb @ 3,500rpm

I'm curious aswell...! :rocks:

[mkoesel]

Originally Posted by swamp2

With some trial and error I got fairly close the the cars reported numbers with 550 hp and 530 ft lb (vs. 500/465 reported).

Yikes.

530 ft-ln / 6.208L = 85.374 ft-lb/L.

I know you were just playing around with the numbers, but I do have to doubt that one.

Still, thanks for posting all your results.

[swamp2]

Originally Posted by mkoesel

Yikes.

530 ft-ln / 6.208L = 85.374 ft-lb/L.

I know you were just playing around with the numbers, but I do have to doubt that one.

Still, thanks for posting all your results.

I don't think the hp number is unrealistic however the torque seems to be. MB is using this exact same engine to get huge power outputs in other applications. It was trial and error, it was quick and this was the only way to get even close on 0-60 1/4 mi time and trap. In the end I was only shooting for average reported numbers as well, not best. In this application the tool helps us conclude that there is a large under rating but does not really pin down the number exactly.

[mkoesel]

Originally Posted by swamp2

I don't think the hp number is unrealistic however the torque seems to be.

Right, no issue with the power number. In fact a race tuned version of the motor could probably hit 800hp easily (though it'd need a rebuild after every race). But even in that kind of application, 85ft-lb per liter would be unlikely and extremely impressive.

[m_bazeepaymon]

Originally Posted by jworms

DCT > 6spd on a track. hell even SMG > 6spd on a track. race teams have migrated over from the standard manual transmission because the sequential systems proved to be faster around a track. if i remember right the e46 M3s had some issues earlier on with overheating of the smg tranny, but after that was taken care of (i think with just some kind of heat sink-like device) it provided quicker laptimes than its 6spd counterpart. i can only assume bmw's new DCT will be even better.

lol just go look at the Nurimbring times thats all I have to say

[m_bazeepaymon]

Originally Posted by swamp2

But you are really making a fool of yourself here. Mixing an insult with your massive misunderstanding really puts the icing on the cake. However, once again I still will not resort to your level with unpleasantries such as "childish" and "stupid".

The only insults I give to you are the Insults you give to everybody else

the only track DCT will succeed in Manual is with a striaght track

[swamp2]

Originally Posted by m_bazeepaymon

The only insults I give to you are the Insults you give to everybody else

the only track DCT will succeed in Manual is with a striaght track

I can not explain the slower Sportauto laptime by the SMG E46 M3 vs. the 6MT. As far as acceleration goes the SMG is slower because of it's launch control problems, not it's shift speeds. South: any idea about the slower lap time. By the way, the track is the Nurburgring, not quite sure what the Nurimbring is maybe a hybrid of the Nurburgring and Nuremburg .

However, like others pointed out there is a reason race cars use autmated manuals, they are faster, period. With proper launch control they are faster in a straight line and faster on a track. Since DCT is a substantially better system than SMG there is no reason to believe it will not be faster on a track. After all tracks do involve acceleration (hmm maybe DCT and SMG can not work accelrating in a curve)

On the insults: I'm fairly carful about that. When letting people know they have made a mistake or I disagree I almost always keep it coridial and factual. If someone really baits me I have been known to take the bait an use insults but that is rare. My post hardly deserved your unpromted attack.

[Garrett]

Originally Posted by m_bazeepaymon

The only insults I give to you are the Insults you give to everybody else

the only track DCT will succeed in Manual is with a striaght track

???



Start educating yourself about Formula One racing. Then, educate yourself on what a DCT actually is. Then learn about why they are in development for consumer cars and why the elite of the Auto industry are moving in that direction.

BMW has been using SMG technology for almost 8 years, DCT are not SMG's, they are a new technology!!!

Your ignorant comments were corrected by several members here. No one was brash with you, but trying to educate you on this technology. This and your other comments were uncalled for. Your clearly misunderstood about what a dual-clutch gearbox is all about.





-Garrett

[southlight]

Hmm, only time I find for an M3 SMG is 8.35. Are we talking about that? That was the E36 M3! Do you guys have a sportauto time for the E46 M3 SMG?

Best regards, south

[!Xoible]

do you guys realize that DCT can be significantly slower in when the computer cannot predict the right gear?

[SunnyD]

Unless you can execute perfect heel-toe down-shifts everytime, I don't see how the manual would be faster than the SMG/DSG/DCT around a track.

In regards to the computer picking the right gear, I would assume you would be shifting for yourself with a DSG type tranny while on the track. Why would you want the computer to do it for you?

[Garrett]

Originally Posted by mantisG35

do you guys realize that DCT can be significantly slower in when the computer cannot predict the right gear?

Yeah, significantly slower than .008 seconds...? So when (if) that happens and it takes 2x or 3x as long to shift, your still shifting in .024 SECONDS!

Look, there are a plethora of people here on these boards (and others) with different experiences and track time. Even when you track every weekend, doesnt mean your the elite of drivers. Heel-Toe is an art form. Just because you can do it, doesnt mean you can do it properly or even precise and certainly not every time..!

Thats they key. Consistancy!

FYI, the very best drivers in the world (Formula1) havn't used clutches in YEARS. These are $150million dollar cars.





-Garrett

[swamp2]

Originally Posted by Garrett

BMW 335 w/PROcede V2.0:

Peak HP: 410hp @ 5,500rpm
Peak TQ: 420ft-lb @ 3,500rpm

I'm curious aswell...! :rocks:

Some may say that my constant arguments of the M3 in favor of a modded 335i contributing my lack of results here. Well I'm not that biased, I'd like to know this as well.

Before messing with the modified 335i I tried to get the base model simulated accurately. Using published hp adn tq specs the numbers don't come out even in the right ball park. Well we know BMW has under rated this car. So I tweaked and tweaked the hp ad tq figures (max values, not so much tweaking of the rpm at which the peaks occur, but a bit) and I can not get anywhere close to good agreement with published performance data. I was using this set. The best I can get on 0-60 and 1/4 mi are 4.93 13.55@100.8. Those numbers are not terrible, but given than NONE of the other 0-X speeds are anwhere close the model is simply not performing. By the way the numbers I used to get the figures above are 380 hp and 375 ft lb!! Probably not realistic crank numbers at all.

Next I tried to enter a fully custom hp vs. rpm curve based on 335i dynos showing peak hp/tq numbers at the wheels of about 275/300 (I used these results and factored in 20% extra for the rw -> crank conversion). Just as in all my attempts these could not match the published performance values either. Clearly If I can't get very close on the base model it is not really worth messing around with the modified version.

I suspect the twin turbos and ECU are making some interesting adjustments that result in a very odd effective tq curves during real use as opposed to on the dyno.

Any other CarTest folks want to chime in, T-Bone?

[swamp2]

Originally Posted by southlight

Hmm, only time I find for an M3 SMG is 8.35. Are we talking about that? That was the E36 M3! Do you guys have a sportauto time for the E46 M3 SMG?

Best regards, south

I have the ME46 M3 at 8:22 and the SMG at 8:35. Maybe the "*" qualifier has something to do with this.

[swamp2]

Originally Posted by mantisG35

do you guys realize that DCT can be significantly slower in when the computer cannot predict the right gear?

Yes, true, +1 to Garrett though and to expand on that:

Having only driven the dual clutch GTI a bit and not on the track I can't say from personal experience...However, from folks who have driven VW/Audi DC units on the track I have heard they are very tough to impossible to "fool".

Also, as I have discussed significantly in other posts, the worst performance of a good DCT system should probably be on the order of the best performance of the SMG system. Some speculation but also if you know roughly how the system works this makes "common sense".

[SunnyD]

Originally Posted by swamp2

I have the ME46 M3 at 8:22 and the SMG at 8:35. Maybe the "*" qualifier has something to do with this.

Better check the date on that M3 SMG time. Unless the e46 m3 SMG was out in 1997, then it's the e36.

[Garrett]

Originally Posted by SunnyD

Better check the date on that M3 SMG time. Unless the e46 m3 SMG was out in 1997, then it's the e36.

Wait, I thought the SMG for the M3 didn't arrive untill 2001/2002? I'm on my iPhone right now so I won't bother to verify. P)

[Garrett]

Originally Posted by BOB Nevada

Is it true that human / Manual gear change is .5-6 sec and SMG /DCT .2 sec so dct will be a quicker car?

Yes, an adept human can shift a gear in about 200ms ~ 700ms. The latest version of SMGIII could shift in about 80ms~90ms.

DCT are said to shift in about 10ms..!!





-Garrett

[Epacy]

Originally Posted by Garrett

Wait, I thought the SMG for the M3 didn't arrive untill 2001/2002? I'm on my iPhone right now so I won't bother to verify. P)

SMG for the M3 came in 2002.

[nusevad]

Originally Posted by Garrett

Yes, an adept human can shift a gear in about 200ms ~ 700ms. The latest version of SMGIII could shift in about 80ms~90ms.

DCT are said to shift in about 10ms..!!


-Garrett

i wonder how R&D is coming along with the DCT...

[swamp2]

Originally Posted by SunnyD

Better check the date on that M3 SMG time. Unless the e46 m3 SMG was out in 1997, then it's the e36.

Ugh, correct, not sure why I missed that one. So back to m_bazeepaymon, where is the data that the M3 SMG is slower on the track than the MT?