Question for post break-in DCT owners

[GT3 Tim]

Car and Driver said:

"On an aggressive shift from first to second, you have to shift around 7200 rpm—nearly 1000 rpm early—to get it to change gears before the engine hits the 8400-rpm limiter"

Do you find this to be true? If so, I am not sure I want DCT anymore.....wtf?

[rai]

I can't offer an answer to your specific question as I have not past 1200.

But i have been playing around with the S-mode. If you are not pushing it, the lag is not much, maybe 300 rpms. But if you are at full throttle it definatly is closer to 1000 rpms. Maybe not 1200 but you can't wait for 7800 rpms if you want to shift. There is a shift warning light that comes on 6500 (or so) more lights as the revs go up so it can warn you about needing to shift before you are too high in the revs..

I think the engine revs so quick at least in 1st or second gear that the time from 7200 to 8200 revs is just a split second. Still a slight delay is there. But you should be able to learn this and of course the D-mode (auto) is going to be the shiznat with D6 full fast auto shits likely better than human control (S-mode) at shifting right at redline but not hitting the rev limiter.

Again, I am not at break-in go tomorrow but have been above 7000 a few times.

[Dascamel]

So it becomes more of an issue of reaction time vs actual delay of the transmission? After watching a few launch videos it seems like 7200-8200 happens very very quickly to begin with.

[GT3 Tim]

Originally Posted by Dascamel

So it becomes more of an issue of reaction time vs actual delay of the transmission? After watching a few launch videos it seems like 7200-8200 happens very very quickly to begin with.

So did it in my GT3. BFD.

If I hit the fricken shift lever, I want that phucker to shift, not delay. I hear all this crap about how fast it shifts...xxx miliseconds, etc....Now it does not appear to shift as fast as I once thought. I guess I will have to wait till I get mine and test drive it first. If I aint happy with it, I wont buy it. So far, I cannot find a DCT to test drive in Nor cal....

If I don't like it, I may just wait for on '09 6MT....phuck it.

[Hammer]

Originally Posted by rai

...

I think the engine revs so quick at least in 1st or second gear that the time from 7200 to 8200 revs is just a split second. Still a slight delay is there. But you should be able to learn this and of course the D-mode (auto) is going to be the shiznat with D6 full fast auto shits likely better than human control (S-mode) at shifting right at redline but not hitting the rev limiter.

...

Do you mean D5 ? Or did i missed something? I thought S1-S6 and D1-D5 and D5~S5 and S6 means "ultimate fun" & max performance?

back to topic:
i guess you ll ve the same prob with a mt reving so fast, you also ve to get timed with shifting if you wont interrupt the floored right food.

[rai]

1st gear shift is at ~40 mph which should take ~3 seconds (ish)

I estimate the time from 7200 rpm to 8200 ~ 0.35 seconds.

[skierman64]

Originally Posted by GT3 Tim

Car and Driver said:

"On an aggressive shift from first to second, you have to shift around 7200 rpm—nearly 1000 rpm early—to get it to change gears before the engine hits the 8400-rpm limiter"

Do you find this to be true? If so, I am not sure I want DCT anymore.....wtf?

I don't think it's 1000 rpm early. However if you wait to shift 1 to 2 until you're at 8100 rpm at full throttle, you're waiting too long and you'll hit the limiter.

The shift lights will help with determining the shift point because they are timed to come on based on the speed at which you're appoaching the rev limit.

I haven't played with it too much, but I'm sure with just a little practice I can determine where I need to shift in order to hit the timing properly.

Honestly I haven't been taking it to redline in first very often and if I was dragging someone, I would certainly use launch control.

It's mostly an issue on the 1-2 shift, of course the higher gears the revs climb at a slower rate.

Overall, DCT is brilliant.

[rick berry]

In S5 or S6 it shifts very fast. Can't wait till 8000 or 8100 to shift. Remember your basically powershifting a fast reving V8. Shift lights help out. I am still sure that I made the right dicision and I am a longtime manual man.

[cchan]

The whole logic of DCT not shifting exactly when you tell it to doesn't make sense. To me, clicking on the paddle/lever to upshift should be equivalent to when I put the clutch in on a standard MT. Shouldn't have to guess how much before redline you need to request the shift - SMG on the E46 doesn't do that.

I was able to get a quick try of DCT, but not enough to be a thorough test/eval. It certainly was not initiating upshifts until noticeably after requested. But this was at relatively low speed, low throttle in street traffic.

If DCT is a significantly different "paradigm" (clicking before instead of when you actually want to shift) I'm going to have to debate it, after the short test and other comments here, I can't say I'd definitively upgrade to DCT from SMG... as much as I like (and want to like) the technology of DCT, if it's too different I'll probably go back to MT.

[skierman64]

I doubt you'd regret buying a DCT especially after SMG

[ajmbmwweb]

if the transmission is anytihing like smg, youre shifting when the red light on the shift indicator comes on. if you were to look straight at the tach, this point in time would not be exactly when the needle is at redline, but by the time you recognize the red light, and pull the paddle, your car has shifted at red line. in fact, the LED system is designed so you dont need to look at the tach, you use your peripheral vision to see the red light and then shift.
so, by the time you recognze the light and shift, the car will have hit redline. as was mentioned before, the climb along the last several hunderd rpm happens so fast, that if you were to see the tach needle go to redline then shift, you would hit the limiter.
after driving smg both on the street and the track for a few years, i can say they really put a lot of thought into it, i suspect the dct is the same

[GT3 Tim]

Originally Posted by skierman64

I don't think it's 1000 rpm early. However if you wait to shift 1 to 2 until you're at 8100 rpm at full throttle, you're waiting too long and you'll hit the limiter.

The shift lights will help with determining the shift point because they are timed to come on based on the speed at which you're appoaching the rev limit.

I haven't played with it too much, but I'm sure with just a little practice I can determine where I need to shift in order to hit the timing properly.

Honestly I haven't been taking it to redline in first very often and if I was dragging someone, I would certainly use launch control.

It's mostly an issue on the 1-2 shift, of course the higher gears the revs climb at a slower rate.

Overall, DCT is brilliant.

Thanks...

So it seems that basically because the motor tachs out so quickly in the 1 - 2 shift, you must shift a bit early. For the rest of the gears, it is more "immeadiate"? Is that correct?

Like another poster said, the whole logic of the DCT is to shift when you want it to....not wait. When I read that you had to anticipate when to shift...ie: pull the paddle before you wanted it to actually shift, I was a bit pissed. that is NOT what I am looking for. However, in restospect, I can understand that the car revs so quickly that you have to initiate the shift a bit in advance. Hearing that the issue is a non issue the higher you go in gears is good news. I think I understand it better now.

thanks again for the post. I look forward to others chiming in with their take.

[GT3 Tim]

Originally Posted by cchan

The whole logic of DCT not shifting exactly when you tell it to doesn't make sense. To me, clicking on the paddle/lever to upshift should be equivalent to when I put the clutch in on a standard MT. Shouldn't have to guess how much before redline you need to request the shift - SMG on the E46 doesn't do that.

I was able to get a quick try of DCT, but not enough to be a thorough test/eval. It certainly was not initiating upshifts until noticeably after requested. But this was at relatively low speed, low throttle in street traffic.

If DCT is a significantly different "paradigm" (clicking before instead of when you actually want to shift) I'm going to have to debate it, after the short test and other comments here, I can't say I'd definitively upgrade to DCT from SMG... as much as I like (and want to like) the technology of DCT, if it's too different I'll probably go back to MT.

My sentiments exactly. But, now that I am reading what others are saying, I can understand the "delay" in the 1 -2 shift. I need to find a fricken DCT to test drive!

Of all the people, you know how fast the GT3 revs in first (being as you own one)...it is almost a non-usable gear at full throttle! I guess I can now better comprehend how their would be a bit of a lag with DCT in this situation. Worse case scenario, I have to "test drive" my car when it arrives. If I don't like it, I will order a 09 M3 or maybe something else.

[mkoesel]

Originally Posted by GT3 Tim

Car and Driver said:

"On an aggressive shift from first to second, you have to shift around 7200 rpm—nearly 1000 rpm early—to get it to change gears before the engine hits the 8400-rpm limiter"

Do you find this to be true? If so, I am not sure I want DCT anymore.....wtf?

This same comment in C&D had me wondering and concerned as well.

Seeing the responses from owners in this thread (and earlier in the thread about the C&D article) is more encouraging, but it still seems a bit of a gray area.

Here is something I would love to here a comment about from owners: What happens if I take the car up to 8300 RPM, and just hold it there, and THEN after a second or two, I upshift? Is there a delay or not? To me there is absolutely no excuse for a delay in such a scenario, and if there is one, then something is not right.

[visor]

Just also want to add: the tach needle does not give a true reading especially when the revs rise quickly. It will always be reading less than the actual rpm in those cases. So, if you don't want to bounce off the rev limiter, you'll have to shift earlier... or use the auto modes if you're driving DCT.

[Socale92]

Originally Posted by GT3 Tim

BFD.

+100000

[Patricius]

As mentioned earlier, look at the shift lights and not the tach. Problem solved.

[cchan]

Ah, I think I didn't read the thread closely enough, so sorry Tim if I took us a little OT. As you said, it was a bit confusing about "reaction time" vs. actual transmission shift delay, I read the latter.

Originally Posted by mkoesel

Here is something I would love to here a comment about from owners: What happens if I take the car up to 8300 RPM, and just hold it there, and THEN after a second or two, I upshift? Is there a delay or not? To me there is absolutely no excuse for a delay in such a scenario, and if there is one, then something is not right.

That I agree with and want to know too. If there is a delay at low rpm/low throttle, I can at least understand (but did not like) that DCT may be pre-selecting the lower gear instead of higher and the delay is due to switching to the higher gear before moving the clutches. That's what I experienced on my short test drive, the delay was so long I wasn't sure it had registered. Hopefully this changes with different shift modes/gear maps, or maybe the car was just new and not broken in or something?

But at a higher rpm, even some below redline, there is no way the lower gear should be pre-selected since a downshift would cause an overrev. So if there is any delay there it makes no sense at all to me. Hopefully this is not the case, can someone confirm this too?

[lucid]

I reported on the upshift delay a few months back with the DSG transmission. I was annoyed with that. Then I test drove DCT, and it is less noticable, but if you look for it, it is there. Is it annoying? I don't know; each person will have a different take on it depending on expectations. And I guess if you live with the car for some time, you'll get use to it and maybe not even notice it. I suggest that you test drive a DCT car for yourself before making a decision.

[swamp2]

Originally Posted by visor

Just also want to add: the tach needle does not give a true reading especially when the revs rise quickly. It will always be reading less than the actual rpm in those cases. So, if you don't want to bounce off the rev limiter, you'll have to shift earlier... or use the auto modes if you're driving DCT.

Sounds like some pretty serious speculation there. Proof in your car? Proof in an M3? Sounds very doubtful to me.

[Mickb]

Lads

In my car, the delay is throttle sensitive. I have posted this before elsewhere, but if you have the throttle pinned past the pressure point that triggers kickdown in auto mode, the gearshift is pretty instantaneous. If you have not hit that point but are still accelerating fairly hard the delay is there.

Mick

[GT3 Tim]

Originally Posted by Patricius

As mentioned earlier, look at the shift lights and not the tach. Problem solved.

Problem not solved.

My issue is with shift delay. The whole point of having a fricken F1-like tranny is that it shifts FAST. I read that it shifts in the milliseconds. Now, 800+ (whatever) rpms between hitting the paddle and shifting is not F1-like, nor is it best timed in the millisecond range.

When I hit that paddle, I want that phucker to shift, NOW. I don't want to have to pull the paddle 800+ rpms early and anticipate it shifting....that is the whole point.