MDCT vs SMG II

[swamp2]

Originally Posted by Sticky

The SMG II is simply a modified manual M3 6 speed gearbox which in itself is just the E39 M5 6 speed gearbox.

SMG III was built from the ground up as a sequential.

No generation of SMG I, II or III was a true sequential. Simply more misnomers by BMW. All SMGs are basically manual transmission boxes with H patterns that are automated.

[synclastica_86]

Originally Posted by swamp2

No generation of SMG I, II or III was a true sequential. Simply more misnomers by BMW. All SMGs are basically manual transmission boxes with H patterns that are automated.

But all 3 doesn't have a torque conveter right? And what is the advantage of an sequential box as oppose to an automated H-pattern box?

[footie]

Originally Posted by synclastica_86

But all 3 doesn't have a torque conveter right? And what is the advantage of an sequential box as oppose to an automated H-pattern box?

Speed is the advantage of a sequential box. Example, normal H-pattern semi-auto completes the shift in 60ms (according to Ferrari) but the reality is close to 85ms, an F1 sequential completes to entire shift in 30ms.

[synclastica_86]

Originally Posted by footie

Speed is the advantage of a sequential box. Example, normal H-pattern semi-auto completes the shift in 60ms (according to Ferrari) but the reality is close to 85ms, an F1 sequential completes to entire shift in 30ms.

Wait does Ferrari use fake/H-pattern sequential box too? I'd think for over 200k, owners do deserve an authentic race experience. And is a clutch needed in a true sequential box? Aren't sequentials cheap? After all, they are used in motor cycles.

[JIO]

I had 3 E46 M3's, all SMG...all driven on the track. My only complaint was it did not rev match off throttle. Other than that, it was wonderful. I don't buy sequential transmissions to drive them in auto mode. I have a DCT on order and I have driven a DCT car many times. For the overall driving experience, the SMG is wonderful and better in my opinion. If I didn't track my cars, I'd get the 6 speed manual. I've seen too many do the money shift on the track to the point of over-revving the engine and in some cases spinning into a wall when the rear end locked up. No manuals for me on the track.

[Sticky]

Originally Posted by swamp2

No generation of SMG I, II or III was a true sequential. Simply more misnomers by BMW. All SMGs are basically manual transmission boxes with H patterns that are automated.

The SMGIII manual box was never offered as a manual and had a very odd shift pattern if I remember, like 7 1 3 6, something weird like that. It is not a box that you could row on your own, it was built as a sequential, not sure how it isn't a true sequential.

[footie]

Originally Posted by Sticky

The SMGIII manual box was never offered as a manual and had a very odd shift pattern if I remember, like 7 1 3 6, something weird like that. It is not a box that you could row on your own, it was built as a sequential, not sure how it isn't a true sequential.

A true sequential gearbox has the gears stacked in a line, meaning you can't by-pass one and go to the next up or down, jump from 5th to 3rd without going through 4th and vice versa. No SMG, either II or III were sequential gearboxes in the true sense of the word. Even the Ferrari F1 box in the road cars isn't a true sequential.

[dawgdog]

I owned an SMGII M3 for 3 years and have had my DCT for a few months. No comparison.

[Serious]

DCT will be superior but we may have to wait for the version in the f10 m5 to fix all the little glitches.

It took bmw 3 tries to get SMG acceptable... hopefully they figure out dct faster then they did with smg.

[swamp2]

Originally Posted by seriousm3

DCT will be superior but we may have to wait for the version in the f10 m5 to fix all the little glitches.

It took bmw 3 tries to get SMG acceptable... hopefully they figure out dct faster then they did with smg.

It is already superior IMO on try 1. There are only a couple of confirmed software glitches and no hardware problems. The confirmed glitches don't seem to be present on all cars and some only appear while on the track. The system is not perfect but awfully close. If past history repeats there will be multiple software updates and the first of which (I think) has already been released by BMW to dealers (but not to customers yet).

[BRETT0429]

I HAVE TO say after driving both i bought the m3 dct and awaiting pick up. before i drove dct i was not as happy with buying a new m3 if it was going to be like the smg. driving the dct is very smooth some people want it to be more racing feel for that i think smg is better for daily driving i pick dct all the way

[Sticky]

Originally Posted by footie

A true sequential gearbox has the gears stacked in a line, meaning you can't by-pass one and go to the next up or down, jump from 5th to 3rd without going through 4th and vice versa. No SMG, either II or III were sequential gearboxes in the true sense of the word. Even the Ferrari F1 box in the road cars isn't a true sequential.

I think we are playing semantics and I have to disagree with you.

The definition of sequential would be characterized by a regular sequence or each following, consequent. The SMG boxes all shift sequentially, 1, 2, 3, 4, 5, etc. You don't go 1 to 5, for example.

How the box itself is set up is not what only makes it sequential, it is also the shifting. A motorcycle is sequential, as are the SMG's. When you click, if the transmission moves all the way across the box to engage second from first, the boxes shift pattern doesn't matter you are still shifting sequentially.

[amgthis]

The SMG sure sounds like a damn sequential:

http://www.youtube.com/watch?v=bCVThnE4KBk
http://www.youtube.com/watch?v=HCnfxai775w

Yes, I also thought SMG III was built from the ground up. I mean, there isn't a seven speed h pattern to base it off of.
But the comparison is SMGII and DCT. I've driven either so it is hard to vote.

[watrob]

I have had both the smg & dtc, I found the dtc box smoother and with 7 gears matches very nicely with high reving V8.

I don't think it comes down to choice at all, I don't think you would choose if given an option of SMG or DTC with this M3 that you would choose a SMG box even if the box had been revised a 4th time.

I feel the e46 M3 is a differnt car to the e9x M3 and the SMG box I don't think would hold up to sitting behind this V8 for 120,000 miles, hence the development of the DTC box.

The merc's had a lot of trouble with there 7 speeds when they first came out, they could not handle the HP that's why the 2006 & 2007 AMG model cars still had the 6 speed boxes in them.

I believe it's what you get use to driving, you will be having this conversation in 4 years time because BMW will have the next generation box out.

I think the next topic about DTC will be dry or wet clutch?

Anyone?

[RaptorKTM]

my m6 has smg 3 and i just recently drove the dct and no question the dct is much quicker however the smg was much for fun to drive, blipping the throttle, rev match capabilities. Due to the lack of interest i have for dct i will be getting the 6mt

[Sticky]

Originally Posted by watrob

I have had both the smg & dtc, I found the dtc box smoother and with 7 gears matches very nicely with high reving V8.

I don't think it comes down to choice at all, I don't think you would choose if given an option of SMG or DTC with this M3 that you would choose a SMG box even if the box had been revised a 4th time.

I feel the e46 M3 is a differnt car to the e9x M3 and the SMG box I don't think would hold up to sitting behind this V8 for 120,000 miles, hence the development of the DTC box.

The merc's had a lot of trouble with there 7 speeds when they first came out, they could not handle the HP that's why the 2006 & 2007 AMG model cars still had the 6 speed boxes in them.

I believe it's what you get use to driving, you will be having this conversation in 4 years time because BMW will have the next generation box out.

I think the next topic about DTC will be dry or wet clutch?

Anyone?

The higher torque AMG's and the 600 benzes kept the 5 speed auto not 6.

They did not really have any "trouble" with the 7 speed it just isn't built to handle the torque of twin turbo v12's.

[synclastica_86]

Originally Posted by Sticky

The higher torque AMG's and the 600 benzes kept the 5 speed auto not 6.

They did not really have any "trouble" with the 7 speed it just isn't built to handle the torque of twin turbo v12's.

This is not true... when their 7speed first came out... the V8 models also retain the 5-speed. Recall last year's SL/S/CL/CLK/CLS/E 55 (not the 63s)? They all lack the new 7speed...

[Sticky]

Originally Posted by synclastica_86

This is not true... when their 7speed first came out... the V8 models also retain the 5-speed. Recall last year's SL/S/CL/CLK/CLS/E 55 (not the 63s)? They all lack the new 7speed...

Huh? Isn't that what I said, the higher torque AMG models retained the 5 speed. What are you trying to say? The SLK55 was one of the V8's that went to a 7 speed.