Shifting functionality on DSG S4

[BirdmanQ5]

Just a small gripe about the shifting on the S4, maybe there's a way to fix it? When I'm driving WOT in manual mode, let's say I take off in 2nd gear - I wind the RPM's up to almost redline and shift high, but it's often when the car decides to shift as well, so it will upshift and then upshift again a second later. Can I not set it to just ping off the redlines if I were to leave it at redline instead of upshift automatically? It's in manual mode - it should trust me to do the shifting just fine.

[mobile S4]

yes - up up down down left right left right b a start

[jl87]

DSG short shifts in manual mode at 6800. It is faster than you so that's why you get the double shift. Not sure these cars even allow vag-com to make it a true manual as far as gear selection, I know older ones you could though. Dynamic mode in auto will shift at 7k (redline) every time (B8).

[Auditude2.0T]

It's like that for a reason, full manual shifting although is very cool- it can overheat the clutch packs very quickly and do more damage than anything..

If you wanted to shift on your own you should have got a 6 speed ;)

All kidding aside I think the DSG drives 10x better in auto mode.

[Leor604]

Why would manual shifting overheat the clutch packs? It's exactly the same shift mechanism, just triggered by a paddle instead of a computer.

[thedollardoctor]

There is NO WAY to bounce of the rev limiter. "Manual mode" is NOT a true manual mode at all. It will let you control up and down shifts in mid RPMs but once you near redline, it will always shift for you. So far as I know, the best solution is the GIAC TCU tune, but you will need to go to at least Stage I for that.

As Auditude said, this is to protect the engine and clutch packs. Many many many people have complained about this. For me, it's a non-issue, if I wanted TRUE manual mode..... I would have bought a manual :-) But I wanted the "faster" version of this car

[BirdmanQ5]

yes - up up down down left right left right b a start

MMI read "Unlimited Boost Enabled"...good find!


DSG short shifts in manual mode at 6800. It is faster than you so that's why you get the double shift. Not sure these cars even allow vag-com to make it a true manual as far as gear selection, I know older ones you could though. Dynamic mode in auto will shift at 7k (redline) every time.

Yeah I figured. I'm still getting used to Super coming from Turbo, so I'm used to shifting really low but I'm making a conscious effort to ride the gears a bit longer. What would you say ideal shifting points are, ideal torque band, etc?


It's like that for a reason, full manual shifting although is very cool- it can overheat the clutch packs very quickly and do more damage than anything..

If you wanted to shift on your own you should have got a 6 speed ;)

All kidding aside I think the DSG drives 10x better in auto mode.

Interesting about the manual shifting. I wanted a 6 speed, but I fell in love with the shift fart and feel of the paddles on the test drive. I actually drive with paddles 70% of the time, sometimes even in traffic. But when trying to decide between manual and DSG, I figured "if you gotta ask whether to get manual or not...it's probably not for you". Last two cars were a Jeep GC and Audi Q5, with short term 6MT A4's between them so I kinda got used to an auto. I'll get a manual again when I own a car that isn't a dedicated daily driver.

[SwankPeRFection]

yes - up up down down left right left right b a start

It's b a b a select start at the end. :p

[Leor604]

There is NO WAY to bounce of the rev limiter. "Manual mode" is NOT a true manual mode at all. It will let you control up and down shifts in mid RPMs but once you near redline, it will always shift for you. So far as I know, the best solution is the GIAC TCU tune, but you will need to go to at least Stage I for that.

As Auditude said, this is to protect the engine and clutch packs. Many many many people have complained about this. For me, it's a non-issue, if I wanted TRUE manual mode..... I would have bought a manual :-) But I wanted the "faster" version of this car

Sorry, but I don't buy that argument.

Why is this car so special that it needs a computer to protect it when every MT and many automated manuals (RS5 for one) will allow you to bounce off the rev limiter all day long.

[thedollardoctor]

Good question.

Someone else mentioned in another thread that one possible reason for the lowered redline on 2013s is all the mechatronics issues they had on the 2010-2012s?

I'm by no means an engineer, hell, I'm not even that smart about cars in general, so take my input with a grain of salt. Just offering my personal opinion. Like I said, I'm not that bothered by the fact that it shifts on its own in manual mode at redline. If I wanted true manual, I would have bought a manual.

[SwankPeRFection]

I think Audi made some bad decisions on this DSG unit since it's within its first couple of designs of it. It's not even rated high enough on the tq specifics that it couldn't make it into the really good cars like the RS6, etc. That should tell you how much Audi trusts it. I think they used the B8 S4 platform as the development test bench for the new unit via public use.

[lapisia]

Yah after a few times of double shifting I ditched the manual mode altogether and just leave it on auto.

[Leor604]

I think Audi made some bad decisions on this DSG unit since it's within its first couple of designs of it. It's not even rated high enough on the tq specifics that it couldn't make it into the really good cars like the RS6, etc. That should tell you how much Audi trusts it. I think they used the B8 S4 platform as the development test bench for the new unit via public use.

Maybe, but they have had five years to get it right and I still doesn't seem that it is fully sorted. Unlike the water pump, control arm and thermostat issues that plagued early B8's, they don't seem to have made any significant progress in debugging the DSG. I *do* hope they eventually get it right because I grudgingly accept that the MT's days are numbered.

[SwankPeRFection]

Maybe, but they have had five years to get it right and I still doesn't seem that it is fully sorted. Unlike the water pump, control arm and thermostat issues that plagued early B8's, they don't seem to have made any significant progress in debugging the DSG. I *do* hope they eventually get it right because I grudgingly accept that the MT's days are numbered.

Well, maybe aftermarket industry leaders such as GIAC should consider visiting shows and other places they normally frequent and aggressively show that their DSG tunes are not only better for the DGS units than Audi's OE, but also saves people from developing problems with them during the life of the vehicle. If they can stand behind their product that much and push and keep pushing against Audi corporate to show them they have the knowledge to properly tune the logic, maybe Audi would entertain looking at what makes GIAC's DSG tunes so much more reliable. Perhaps it would even entertain more dollars on a contractor basis for GIAC to help the Audi OE boys out a bit. Unfortunately, I don't think anyone at GIAC has the lungs to be loud enough against Audi corporate to have their voices heard and help solve problems for the community as a whole.

This isn't a knock on GIAC... I'm just saying... If your DSG tune can be enough to solve these problems because it's more efficient, then yell it out loud when you go to these shows where Audi is present and maybe make a few phone calls to get your foot in the door for them to hear you out. Build a fleet of vehicles large enough with your DSG software and put hundreds of thousands of miles on those trannies and they will eventually hear you and see your work.

[Leor604]

Ummm, the GIAC DSG software became available 10 days ago. I think it's a bit early to draw any conclusions about reliability relative to stock software.

[Bronx Cheer]

The double up-shift is not a problem. It is the double down shift that is a problem. In WOT mode, just don't shift if you want to "redline" the car (i.e., go up to what the factory says is the top recommended RPM for shift) - the car will do it on its own. It just so happens that the real redline is 6800 instead of the 7000 shown on the tach.

I have a big problem problem with double down shifts. You have no idea whatsoever when the car is going to want to downshift, so I end up double down shifting fairly often with the car going into 1st at overly high speed at times. Not good. You basically are left with having to down shift well in advance of when you really want to do so. The car should have the electronic ability to ignore a downshift command if the car had done one on its own immediately prior, but it does not seem to do this (or the ignore window is too short).

[SwankPeRFection]

^^^ I think it's just bad logic programming. Audi should have programmed this thing to bounce off the rev limiter for 3-5 time before forcing an automatic upshift for the user. On downshifts, it should have a table for speed vs rpm vs gear and not let it go into a lower gear that would raise the rev above the 4-5k RPM mark. It really is just as simple as that.

[VeryBadman]

yes - up up down down left right left right b a start

HAHAHAHAHA you crack me up real bad!
That would enable the sudden boost when you click both of the dial buttons on the steering for 30 times! [;)]

[cspcrx]

I only use the paddles to down shift. If I am going into a turn and have the care in S mode I will use the paddles to go down gears to keep the revs up for a strong pull out of the turn then let the car up shift.

[gdawg'05a4]

There is NO WAY to bounce of the rev limiter. "Manual mode" is NOT a true manual mode at all. It will let you control up and down shifts in mid RPMs but once you near redline, it will always shift for you. So far as I know, the best solution is the GIAC TCU tune, but you will need to go to at least Stage I for that.

As Auditude said, this is to protect the engine and clutch packs. Many many many people have complained about this. For me, it's a non-issue, if I wanted TRUE manual mode..... I would have bought a manual :-) But I wanted the "faster" version of this car

I would check the transmission module with VAG-COM under coding. On the 8-speed gear boxes, you can disable auto up-shift in manual mode and it'll bounce off the rev limiter if you don't up-shift.

[thedollardoctor]

I would check the transmission module with VAG-COM under coding. On the 8-speed gear boxes, you can disable auto up-shift in manual mode and it'll bounce off the rev limiter if you don't up-shift.

That would be badass if it could be changed by VAG COM, but to my knowledge this is not possible on the 7-speed

[Austin@GIAC]

Why would manual shifting overheat the clutch packs? It's exactly the same shift mechanism, just triggered by a paddle instead of a computer.

One clutch pack must engage while the other disengages on the shift. This is all timed based on RPM. If you hit the point where it should start the shift, then back down below it, the clutchpacks will effectively go back and forth over and over. It's like rapidly shifting, without actually doing so. The more work these gearboxes perform like that, the more heat they generate.

[rs4dreams]

One clutch pack must engage while the other disengages on the shift. This is all timed based on RPM. If you hit the point where it should start the shift, then back down below it, the clutchpacks will effectively go back and forth over and over. It's like rapidly shifting, without actually doing so. The more work these gearboxes perform like that, the more heat they generate.

Could you elaborate on that explanation? It's interesting and good to know more details about how the DSG operates.

[BzzzBom]

Could you elaborate on that explanation? It's interesting and good to know more details about how the DSG operates.
+1

[drob23]

One clutch pack must engage while the other disengages on the shift. This is all timed based on RPM. If you hit the point where it should start the shift, then back down below it, the clutchpacks will effectively go back and forth over and over. It's like rapidly shifting, without actually doing so. The more work these gearboxes perform like that, the more heat they generate.

I'm sure the powertrain control engineers designed some kind of "anti-hysteresis" logic, where the shift surfaces in the maps (pedal (RPM) vs Velocity) don't overlap, i.e. 2->3 does not intersect with 3->2. Thus imposing some mandatory minimum dwell time if you will.

http://www.mathworks.com/cmsimages/63422_wl_91968v00_powertrain_fig6_wl.jpg

[Leor604]

One clutch pack must engage while the other disengages on the shift. This is all timed based on RPM. If you hit the point where it should start the shift, then back down below it, the clutchpacks will effectively go back and forth over and over. It's like rapidly shifting, without actually doing so. The more work these gearboxes perform like that, the more heat they generate.

Okay, but this seems to be a function backing off the throttle at the wrong time, not of manual shifting.

[SwankPeRFection]

I don't see why the clutch packs have any business disengaging at any time whether you're on the gas or off the gas. The only time they need to disengage is to shift up or down or to keep the engine from stalling if the RPM are too low in relation to the speed of the car. After all, on a MT, you don't need to disengage the clutch when you're not accelerating. The clutch remains engaged on and just causes engine breaking. The only time you modulate the clutch is to shift or to keep it from stalling, anything else is not needed. If the DSG does not work like this, it's no wonder they overwork the clutch packs, damn... please say the packs don't disengage whenever you're not steady on the accelerator, seems stupid.

[scrofas5]

have had that happen just a few times to me, but whenever i race i put it in "s" not manual mode, ill let the computer work to prevent the double shift. i drive 50/50 from d to m mode everyday, but i only use m mode to get a certain rpm in the power band, since the b8.5 has pretty tall gearing from 3rd up, so im mainly not shifting anymore than i have to than in d mode and preventing any dbl shifting. but regardless i think it takes a lot more than a 1 or 2 spirited pulls in a row to trigger overheating!! its just taking care of your transmission on a daily basis, letting it get up to temperature when you first start the car and leaving it in drive for atleast 4 min, and not ringing out the motor on a cold start, these are my rules.

[Austin@GIAC]

Okay, but this seems to be a function backing off the throttle at the wrong time, not of manual shifting.

No, it's not. This function occurs with our DSG software and the throttle stays open through the shift.

[Austin@GIAC]

I don't see why the clutch packs have any business disengaging at any time whether you're on the gas or off the gas. The only time they need to disengage is to shift up or down or to keep the engine from stalling if the RPM are too low in relation to the speed of the car. After all, on a MT, you don't need to disengage the clutch when you're not accelerating. The clutch remains engaged on and just causes engine breaking. The only time you modulate the clutch is to shift or to keep it from stalling, anything else is not needed. If the DSG does not work like this, it's no wonder they overwork the clutch packs, damn... please say the packs don't disengage whenever you're not steady on the accelerator, seems stupid.

It's all an orchestrated process. If you break one portion, you get stuck in a loop, like any other normal programming.

[Austin@GIAC]

I'm sure the powertrain control engineers designed some kind of "anti-hysteresis" logic, where the shift surfaces in the maps (pedal (RPM) vs Velocity) don't overlap, i.e. 2->3 does not intersect with 3->2. Thus imposing some mandatory minimum dwell time if you will.

http://www.mathworks.com/cmsimages/63422_wl_91968v00_powertrain_fig6_wl.jpg

The car doesn't actually shift. The transmission starts to orchestrate the steps required to shift, then stops, then starts, so on and so forth.

[helix139]

One clutch pack must engage while the other disengages on the shift. This is all timed based on RPM. If you hit the point where it should start the shift, then back down below it, the clutchpacks will effectively go back and forth over and over. It's like rapidly shifting, without actually doing so. The more work these gearboxes perform like that, the more heat they generate.

So why not raise the point where it should start the shift to a point above the redline for manual mode only, based on what you're saying, wouldnt that prevent the clutch packs from engaging and disengaging and thus prevent a shift until the paddle is pressed? I don't see why it has to be inherently worse for the transmission or clutch packs to hold, say, 6800 rpms as opposed to 7000 rpms.

[SwankPeRFection]

The car doesn't actually shift. The transmission starts to orchestrate the steps required to shift, then stops, then starts, so on and so forth.

Correct, you're talking about the clutch that's currently in the secondary process waiting to either shift up or down depending on what the user may call for. I've looked at diagrams to try and get a better idea of which clutch is open and which shaft is engaged on the next higher or lower gear in preparation for the next clutch to clamp and engage that gear, but nobody has a good drawn up or animated video example of it. That said, I'd like your input on if I'm sitting in line at a drive through or something else, what would cause less hear generation or wear/tear on the transmission? Leave the DSG in gear and continue standing on the break, Slide the shifter in N, Slide the shifter in P? I would think that sitting in gear and standing on the gear keeps that tranny engaged in with one clutch open/shaft engaged on 2 and the currently main/active clutch open and holding over 1 so you can inch up. On a manual, this would constitute a tired left foot. lol Would the same hold true for a DSG waiting for you to let go of the break to start to slip the clutch? Wouldn't throwing it in N make it all relax? Contrary to this, throwing it in P wouldn't be as efficient because as you pull it down, you're traversing R and N and the shafts/clutches have to prepare those gears before it realizes you want to be in D.

Please help clarify this if you can. I hope I made just a bit of sense in what I was trying to put into textual words.