Z4 35i DCT>M-DCT?

[persian54]

I drove the Z4 again after sometime in the M3..and... call me crazy, but I think the Z4 DCT is better than the M one...

Smoother in D mode
Comparable in S mode versus M DCT D5

and the fact that.. you can be in D cruising in 7th, then move the lever to S and it'll dump into 4th gear, lower if possible and if you go WOT... where with the M, even after you press the M button (power on, D5, etc), it won't downshift to such a low gear unless you go WOT (or press the throttle then let go so it'll go into the lowest possible gear)

Or am I completely missing something and just haven't driven the M enough?

[eVitO]

What happened to breaking in you car? ;]

[persian54]

Originally Posted by eVitO

What happened to breaking in you car? ;]

I have a good amount of miles on her now

[termigni]

so you own both? 35i's torque is no joke... that may be why.

[persian54]

Originally Posted by termigni

so you own both? 35i's torque is no joke... that may be why.

Yes we have both

I gave my Z4 to my mom so it's still in the family.

I know the torque is no joke; i had a 335i with over 400wtq before the Z4; and when I had the Z4 I had it at 350wtq.

But right now I'm comparing stock as I de-tuned the Z4 for my mom.

Just referring to the transmission
and mainly it going from 7 to 4 (or 3) without the needed of throttle increase versus the M where you would need to use throttle

I like the way the Z4 is in that it's in the right gear when I want it to me on that downshift (this is no means a 6MT vs DCT discussion btw)

[swamp2]

Sounds obvious that the software is different. It has probably been improved in some ways. However other changes might simply be a matter of preference. I am interested in other changes. Many of them might be more subtle than this one you already pointed out.

[persian54]

also I'm in no way saying the M DCT is bad

I love the M DCT

but this is something that just came to mind

I remember when researching the DCT trans in the Z4 to see how much max torque it can handle, I found that it is the same DCT as the M except it can't handle as much torque (400 i think was the max I read, been a while so I don't remember exactly)

[ChrisK]

I drive my DCT in D4 and it's smooth as butter.

[persian54]

Originally Posted by ChrisK

I drive my DCT in D4 and it's smooth as butter.

hard or soft butter?

i kid i kid

[ChrisK]

Originally Posted by persian54

hard or soft butter?

i kid i kid

+1 LMAO!

[SunnyD]

Are the DCTs in the M and non M's the same? Is software the only difference between the two?

[persian54]

Originally Posted by SunnyD

Are the DCTs in the M and non M's the same? Is software the only difference between the two?

essentially the same

[Edward]

^ really? I heard the M3 one has way more modes. On my DCT I only have D, DS, and M modes. You can press the sport button which alters boost and also quickens the shift even more, I kind of don't count that as a DCT mode.

[424D57]

Originally Posted by Edward

^ really? I heard the M3 one has way more modes. On my DCT I only have D, DS, and M modes. You can press the sport button which alters boost and also quickens the shift even more, I kind of don't count that as a DCT mode.

I think the hardware in the gear box itself (getrag iirc) is the same. Modes of operation, the contoller, and behavior vary drastically.

-424D57

[persian54]

Originally Posted by Edward

^ really? I heard the M3 one has way more modes. On my DCT I only have D, DS, and M modes. You can press the sport button which alters boost and also quickens the shift even more, I kind of don't count that as a DCT mode.

Originally Posted by 424D57

I think the hardware in the gear box itself (getrag iirc) is the same. Modes of operation, the controller, and behavior vary drastically.

-424D57

^This

Why I said "essentially"

You have D, DS, and M

We have D1-5 and S1-5 (S meaning Manual mode)

So yeah in that since the MDCT has much more to play around with...

But I was referring to D5 and S (with sport+ activated on the Z4), essentially both models highest sport modes

[zamm3k]

I think one of the biggest differences is going to come in the fact that on the Z4 you get torque at much lower RPMs, as opposed to the M3's S65 higher torque and power curve, so software has been optimized for each engine mated to its tranny. Obviously, both having the same tranny, will behave very differently, just like the two different engines they're mated to.

[persian54]

I'm not talking about the jump in acceleration or the power or the feel of the power

I'm referring to the Z4 going from 7 to 3 (or 4) without anything other than going from D to S

Where in the M, it'll go from 7 to 5, or sometimes 6, unless you really give it throttle

[kitw]

so... because the car automatically downshifts, you like it better? Give me a break. If you want to downshift, then downshift.

I owned a Z4 Sdrive35i before my e90 M3 M-DCT and there is no comparison. The M3 is faster shifting and more response and also doesn't have the stupid push/pull paddles.

In Sport Plus, the Z4 is not as fast as the M3, especially not at redline.

The Z4 had one advantage which was it didn't take as long to engage the clutch from a standstill. After that, there is no comparison.

[e46e92love]

Originally Posted by persian54

and the fact that.. you can be in D cruising in 7th, then move the lever to S and it'll dump into 4th gear, lower if possible and if you go WOT... where with the M, even after you press the M button (power on, D5, etc), it won't downshift to such a low gear unless you go WOT (or press the throttle then let go so it'll go into the lowest possible gear)

Or am I completely missing something and just haven't driven the M enough?

I for one have always preferred the logic on the SMG and now the M-DCT logic with no changes happening to the gears when you shift from "automatic" mode to "manual" mode. That is how it should be. Sounds like the regular DCT is like the upgraded ZF they offer in the 335i, where when you push hte lever over it dumps in sport mode, and immediately down shifts, forcing you to then hit the paddles or the stick to shift gears and put it into "manual" mode.


Cheers,
e46e92

[kaykay]

I believe they both use the same GETRAG DCT transmission. The Z4 has a different engine and different software which is where you're getting this feel from. It could be smoother due to the software but they are both configured and tuned for completely different purposes (Z4 vs. M3).

I haven't driven the Z4 DCT so can't comment, the M-DCT is a great gearbox, however, the DCT on the 911 "S" is a much better DCT transmission, better shifting, seamless, I just love it so much more than the Getrag on the M-3.

I'm going to drive a friends 458 Italia next week (which also uses Getrag DCT) and see how that compares.

I'd give the M-DCT a 8.5/10, 911 PDK a 9.2/10.

As a corollary, the SMG on the M5/M6 is a solid 5/10 gearbox. Haha.

[MVF4Rrider]

Originally Posted by kaykay

As a corollary, the SMG on the M5/M6 is a solid 5/10 gearbox. Haha.

Hope you're joking. It's not smooth but it isn't a dual clutch gearbox either. It's not meant to be smooth as it's replicating what a human would set in motion with a clutch and gearstick (it's more fair to compare to 6MT than DCT). It's actually a genius mechanism/electronics to control the exact same gearbox as the standard manual. The fact I can barely inch forward in a completely controlled manner and with amazingly smooth operation by barely raising the throttle is simply incredible...and release the throttle it goes straight back to neutral on its own. Try doing that with a 6MT. When I read comments like yours it just shows me how soft the new-age consumer is. I have 25K miles using a DSG gearbox and I greatly appreciate the lightning fast shifts, but dual clutch gearboxes have operational (torque limitations), weight, and reliability penalties as well. Personally I like the kick in your pants shifts of the SMG, and if I ever want to convert it to a standard 6MT that is possible. It's one thing to appreciate the latest and greatest, but it's sad when a great invention is unfairly dissed. I'm happy in the fact I'm not so enamored by all things new (same for all the .2 997 Porsche weenies which have an upgraded car but the same limited skills so it's moot). New often times = less involved and less manly and less character.

Want to experience a shitty gearbox(?), drive a 2009 MINI JCW.

Off soapbox now...

[persian54]

I rarely rarely go on the freeway when it's open (there's always traffic when I go)
but last night, on the 118 when it was empty, I was able to play around a bit

When I was cruising in 7th D3, and I pressed the M (turning on everything and D5 etc), with a small blip of the throttle and it jumped into 3th and launched me forward the way I like it, basically want the Z4 DCT was doing.

I think that since the Z4 has more torque in the low end the DCT behaves the way it does.

Originally Posted by kitw

In Sport Plus, the Z4 is not as fast as the M3, especially not at redline.

The Z4 had one advantage which was it didn't take as long to engage the clutch from a standstill. After that, there is no comparison.

Actually, I didn't have a stock Z4... and my Z4 was much faster than a M3 from 0-100.
AFter 100 was when the 3.0 I6 died and the M3's V8 would roar.
I did several runs with my friends e93 M3 DCT

I actually prefer that there's no torque converter in the M3 and it doesn't really move forward from a standstill
This way, my foot can be over the gas so if I need to go, I go.
Where with the Z4, and also an automatic car, you foot has to be on the brake, otherwise you are edging forward.
I keep my left food ready to press the brake if need be though.

Both are great cars and both have great transmissions.

I never said I felt the M DCT was bad.... it's not.

I remember the SMG from the e46... it wasn't smooth at all lol
But it was still great, especially for technology from the last decade

I didn't drive the m5 enough to remember how it drove