GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

2019 GTI 6MT Performance Issues I'd Like to Correct

dosjockey

Go Kart Champion
Location
South
I just don't like the use of the word "better" when what is closer to the truth is "preferred". I get that people prefer predictable mechanical behaviour, but I suspect that the car with the trick electronic diff is actually better in terms of being able to control the car's attitude and progress in extreme circumstances.

Honestly, if VW offered a thousand dollar option (and sign a waiver) for one small switch bank in the glove box to disable the systems individually, easily, and permanently, they would be cool features to have. If there were sliders to adjust for each system (and there could have been), it would be a highly desirable feature set.

I don't have an aversion to electronic wizardry so much as I do it's power over the experience and difficulty of defeat. I'm a computer guy, after all; it's right in the name. :)

At the limit, yes. A system like this can keep a car more stable; but stable isn't always the correct choice in a dynamic environment. Consistency is also important, and these systems are inconsistent. One can design computerized systems that are outstanding at the limit, and one can even build them; but they'd cost more than the Golf itself. There's also using computers to do "mechanical" things. The idea of adding pressure to a clutch pack with a selection in a menu is amazing, for example; so long as it's always adding it the same way, and so long as it's always there in differentiation scenarios, and fails to a functional mechanical state when something goes wrong.

I need to run through golfdave's VAQ thread again to come to a better understanding of what I've done by setting mine to "Increased Traction" mode. It does feel different, but I'm carefully working back up out of granny driving again after changing the setting, so I haven't pushed anything just yet.

I'm trying my hardest to come up with analogies here for why it's important to be able to lose traction and keep it lost until you want it back, but falling short in explanation. ?
 

dosjockey

Go Kart Champion
Location
South
Most stability systems are "pro-active"..& the VAQ is to an extent...& that's the problem...

It relies on pre-programmed data tables & possible scenarios to compare the current situation to.....& there for it "thinks" you are in "trouble " & intervenes, even thought it cannot "see" the road or the conditions...

8 out 10 times it might get it right...but the other 2 it can balls up....

This is why in many cases a more "advanced" driver actually has to forget to drive & just let the car do its thing as they are ALL dumbed down to the lowest common demominator...ie a thick driver...

P.S. the VAQ unit is used on only the DSG cars in the TCR race series (sequential gearboxes have a different setup)…& they have special programmes written for them...these would be far better for the OP...but you can't get your hands on them...

Indeed, and it's those other two events that make it a system that's not always appropriate for everyone.

I'm going to read your thread again, but any spoilers on precisely what I've done by setting this differential to "increased traction" mode? I've only got about a few miles on it since the change, and I'm nowhere near pushing it yet. Haven't brought it past 3,000 revs since the change, nor have I turned hard enough to make the systems blink. I like to try things out carefully at first.
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
Indeed, and it's those other two events that make it a system that's not always appropriate for everyone.

I'm going to read your thread again, but any spoilers on precisely what I've done by setting this differential to "increased traction" mode? I've only got about a few miles on it since the change, and I'm nowhere near pushing it yet. Haven't brought it past 3,000 revs since the change, nor have I turned hard enough to make the systems blink. I like to try things out carefully at first.


I' don't know all the ins & outs & exact "meanings" of the possible VCDS alterations (most of the known ones are still "suck it & see"), but many of the items listed in the VAQ, ABS, & Engine units will "loosen" of the nanny's.....however some you can't alter ever with security code inputs...VCDS alterations will not void the warranty, nor will it raise a TD1 flag as you are just ticking a different box on the VAG software....
 

dosjockey

Go Kart Champion
Location
South
I' don't know all the ins & outs & exact "meanings" of the possible VCDS alterations (most of the known ones are still "suck it & see"), but many of the items listed in the VAQ, ABS, & Engine units will "loosen" of the nanny's.....however some you can't alter ever with security code inputs...VCDS alterations will not void the warranty, nor will it raise a TD1 flag as you are just ticking a different box on the VAG software....

I wonder if it's firing up that pump just a bit, but all the time with that mode selected. Is it possible it can add a little "preload" after all?

It does feel a little more planted and responsive in normal driving; but it could have also affected another system that's causing the different feel. I've no way to eliminate the variables.

It's certainly a bit frustrating when the data just plain isn't available. That's kind of pig-headed on VW's part.

Yeah, the dealer said odds are there's no flagging for simply changing values. I wouldn't expect there would be, but it was worth asking about first. I still haven't found a way to disable torque limitation completely.
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
I wonder if it's firing up that pump just a bit, but all the time with that mode selected. Is it possible it can add a little "preload" after all?

The pump does add pre-load to get the VAQ work...but there is a lower limit where it can't so it uses the ABS systems...............….loads in the TCR race cars..read the thesis!!
 

dosjockey

Go Kart Champion
Location
South
The pump does add pre-load to get the VAQ work...but there is a lower limit where it can't so it uses the ABS systems...............….loads in the TCR race cars..read the thesis!!

I'm trying to read it. ?

Didn't see this specifically mentioned in there, as the way I'm reading it there is an implication that it can't provide preload by itself. Maybe I'm just not interpreting the wording properly.

For example, I don't quite follow the two statements with the periods in between them in the quoted post. I know not all the answers are fully understood, but the questions I'd ask would be what is the nature of that limit; is it a requirement of a certain amount of wheel speed difference? Does changing to increased traction mode actually increase that preload at all times, rather than only when that difference is detected?

I don't know what "loads in the TCR race cars" means when typed in isolation.

The car does feel slightly different; as if it's got a very mild limited slip installed now; rather than a nothing that turns into a something when it's required. That could be some of these other systems reacting differently, though.
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
I'm trying to read it. ?

In answer to some of your questions I quote:-

What about the “preload” problem?
One of the disadvantages of some LSD’s is that they require a small amount of mechanical force/torque imbalance to overcome the internal resistance in the LSD unit & start the “lock up” & transfer of torque to the wheel with the most grip. Most modern LSD units get around this with various “bump wave” cogs/ramps, or by altering the end friction plates or the gear oil “W” rating.

The FDL unit is supposed to not have this problem as its an electrohydraulic clutch pack diff lock. Unfortunately it has a “preload” type problem & has to use the existing XDS brake based system in certain limited conditions.

Ultimately the FDL unit has no direct mechanical way of activating the clutches, so in effect it has a huge “pre-load” problem. The FDL cannot “sense” torque through the drive shafts & thus cannot use this to activate the pump to activate the clutch’s. It has to be “told” what the wheel speed is from the external ABS sensors as it does not have its own sensors. Therefore even if you leave the FDL unit powered but disconnect it from the CAN bus or just the ABS unit, it will not work as it is not a “stand alone” unit, & thus NOT a mechanical LSD!


Don’t the Seat & VW TCR race cars use the FDL unit?
Only the DSG gearbox versions of the Seat Leon & VW Golf TCR Race cars use the same FDL unit as MK7 Golf GTI “PP”. The cars fitted with the SADEV 6 speed sequential gearbox (SEQ) have their own clutch/ramp type mechanical LSD with sun & planet gears in place of the “open” diff in the gearbox. This SEQ LSD has an external adjustment screw for a “preload” setting, & you can get different “ramp” sets, again to alter the characteristics.

The “Electronic modules” specification lists the “ABS/ESP” unit as “Continental” (actually the MK100 unit), & “Software” for the unit as “Not active”. This proves that although the ABS unit is fitted, it is “inactive”. The reason for this is that the ABS unit is required as a “pass through” for sensors:- G44, G45, G46, G47 (ABS wheel sensors), G200 (lateral acceleration sender), G202 (Yaw rate sender), G251 (longitudinal acceleration sender), as the FDL unit requires the data from these to decide to activate or not! Without these is cannot work!

The “Electronic modules” specification also lists the DSG Mechatronic as “VW” with “Motorsports” software, & the FDL unit as “Borg Warner” with “Motorsports” software.

The 2015 Seat Leon Cup racer lists 3 switchable maps available in the control unit of the FDL unit.
Map 1:- Base mode, no over slip, only yaw damping above 110km/hr, 300Nm preload during braking. For high grip (new tyres).
Map 2:- Like map 1, less yaw damping, 200Nm preload during braking. Medium grip (used tyres).
Map 3:- Preload dependant on engine torque, 200Nm preload during braking (releasing earlier than Map 2). Low grip/rain.

Please note that this engine has a maximum specified torque of 410Nm, so the FDL unit is applying half, or more, of the engines torque figure as “preload” during braking.
 

dosjockey

Go Kart Champion
Location
South
In answer to some of your questions I quote:-

What about the “preload” problem?
One of the disadvantages of some LSD’s is that they require a small amount of mechanical force/torque imbalance to overcome the internal resistance in the LSD unit & start the “lock up” & transfer of torque to the wheel with the most grip. Most modern LSD units get around this with various “bump wave” cogs/ramps, or by altering the end friction plates or the gear oil “W” rating.

The FDL unit is supposed to not have this problem as its an electrohydraulic clutch pack diff lock. Unfortunately it has a “preload” type problem & has to use the existing XDS brake based system in certain limited conditions.

Ultimately the FDL unit has no direct mechanical way of activating the clutches, so in effect it has a huge “pre-load” problem. The FDL cannot “sense” torque through the drive shafts & thus cannot use this to activate the pump to activate the clutch’s. It has to be “told” what the wheel speed is from the external ABS sensors as it does not have its own sensors. Therefore even if you leave the FDL unit powered but disconnect it from the CAN bus or just the ABS unit, it will not work as it is not a “stand alone” unit, & thus NOT a mechanical LSD!


Don’t the Seat & VW TCR race cars use the FDL unit?
Only the DSG gearbox versions of the Seat Leon & VW Golf TCR Race cars use the same FDL unit as MK7 Golf GTI “PP”. The cars fitted with the SADEV 6 speed sequential gearbox (SEQ) have their own clutch/ramp type mechanical LSD with sun & planet gears in place of the “open” diff in the gearbox. This SEQ LSD has an external adjustment screw for a “preload” setting, & you can get different “ramp” sets, again to alter the characteristics.

The “Electronic modules” specification lists the “ABS/ESP” unit as “Continental” (actually the MK100 unit), & “Software” for the unit as “Not active”. This proves that although the ABS unit is fitted, it is “inactive”. The reason for this is that the ABS unit is required as a “pass through” for sensors:- G44, G45, G46, G47 (ABS wheel sensors), G200 (lateral acceleration sender), G202 (Yaw rate sender), G251 (longitudinal acceleration sender), as the FDL unit requires the data from these to decide to activate or not! Without these is cannot work!

The “Electronic modules” specification also lists the DSG Mechatronic as “VW” with “Motorsports” software, & the FDL unit as “Borg Warner” with “Motorsports” software.

The 2015 Seat Leon Cup racer lists 3 switchable maps available in the control unit of the FDL unit.
Map 1:- Base mode, no over slip, only yaw damping above 110km/hr, 300Nm preload during braking. For high grip (new tyres).
Map 2:- Like map 1, less yaw damping, 200Nm preload during braking. Medium grip (used tyres).
Map 3:- Preload dependant on engine torque, 200Nm preload during braking (releasing earlier than Map 2). Low grip/rain.

Please note that this engine has a maximum specified torque of 410Nm, so the FDL unit is applying half, or more, of the engines torque figure as “preload” during braking.

Lord knows I must have read that fifty times (even printed it) and still got the portion I highlighted with bold text backwards... ?

I think the second paragraph was confusing me a bit when combined with that particular quote. Sometimes it helps to re-type something I read, but I didn't think to do that.

So, it's basically now working more like a very subtle, normal clutch-based limited slip, which is why it feels much more nimble and planted. That would mean that I've done is the electronic equivalent of adding a few shims or otherwise tightening a clutch pack. If the car is running, it's now adding more preload than it would have otherwise; which will naturally prevent the ABS from stepping in to transfer rotational energy as often, because it's not going to sense as much slip.

I mean... Aside from the fact that the engine still robs me of torque in lower gears, that's not a bad design overall. If it was infinitely adjustable and the system wasn't so trigger-happy, it would be the cat's ass for racing on varied terrain; adjusting clutch pack preload on the fly? That's pretty cool if the driver was in total control of it. Kind of reminds me of the STI center. In that way it's like just about everything else on this vehicle... They're about 90% to perfection, but just fell short trying to dial it in for people who either don't have the skill, or simply don't feel like using it.

Are my impressions and conclusions accurate, or am I still missing something? I think I've got it now. :unsure:
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
Are my impressions and conclusions accurate, or am I still missing something? I think I've got it now. :unsure:

Much better.....& yes in theory you could have a tweak dial like a brake bias knob to swap "maps" for the VAQ unit....all you are telling to do is have the pump on pre-pressure of x%..so no lag...& partial lock up.....so for drag launch, 100% lock up......car park manoeuvring no lock up...…& without having to get ABS systems involved...
 

dosjockey

Go Kart Champion
Location
South
Much better.....& yes in theory you could have a tweak dial like a brake bias knob to swap "maps" for the VAQ unit....all you are telling to do is have the pump on pre-pressure of x%..so no lag...& partial lock up.....so for drag launch, 100% lock up......car park manoeuvring no lock up...…& without having to get ABS systems involved...

Cool. That jives with what I'm feeling in the car now.

I had to go out tonight to hit the pharmacy, and took a slight detour to the exact same place that the car tried to bite me the other night, and pushed it through the same scenario; or at least as close as I could get it.

It still threw some punches at me every time I tried it, but at least a second later than before; if not two, and it was much more manageable. It was about ten degrees warmer, but that's too big of a difference to be entirely temperature related; and the road had already cooled for the evening. So, it's much better now. It really does seem like the ABS is coming in later, simply because the thing has more traction to begin with. It's much more predictable, as a result.

If I back off the XDS or whatever it's called (can't remember right now), the car might be dialed in as well as I'd expect a modern production vehicle to be, so far as traction control and the differential are concerned.

Sure hope I can get rid of that torque limiter without a tune; but maybe backing off that other system will tame that a little, as well. I know they're integrated at least to some degree. There is also the possibility that it's simply been renamed. Seem to remember at least one person saying they'd found it under a blank label. It won't hurt to look.
 

dosjockey

Go Kart Champion
Location
South
Well, I found the actual limit this time.

Still being within the break-in period, it's been important for me not to really push things, but to get where I needed to be, I just did a part throttle launch into a right turn to really get a wheel spinning.

The wheel spun, obviously, and the ABS traction control itself wasn't too intrusive for general use at this point. I was able to manage that well enough; not ideal, but overall not too bad now. By itself, it was pretty standard and functional ABS traction control. The problem was, after a couple of seconds of thinking the vehicle was going to do what I wanted, it cut fuel on me. It just plain gave up and fell on it's face.

So, I'm still fighting the torque limitation, but beyond that if I really want to break traction in a turn (or if I actually wanted to do silly launches)... It's still not going to do it.

How many obstacles did they think this car needed, for crying out loud?

Something tells me there's nothing I can do about this particular problem. Seems like something that would indeed require a tune to get rid of, which I don't want to do. That's not good for a warranty, obviously, but I also see no need for additional power on this vehicle, so it would just be personalizing the output, anyway.
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
VCDS loads.....

also using the "driver mode" button, select "individual" & set everything to "sport".....the "individual" mode is retained after each ignition switch off....where as if you use the other modes they all default back to "normal" after each ignition switch off...

PS its not the car..its to dumb down for the unskilled thicko drivers who want to feel like a "driving god"....
 

Reggie Enchilada

Autocross Newbie
Location
nowhere
Car(s)
yes
I may have found the replacement for the starting vibration reduction on the MK7.5's when I was playing around in OBDEleven the other night. There is a new category under the same module in a similar place called "Rough Road" with the options for Enabled and Disabled. I disabled it on mine and am testing it out currently. Initial results on wet roads were positive, it felt like my 2016 did after disabling SVR. Now that the roads here have dried up, I'm going to test it out more tonight.
 

dosjockey

Go Kart Champion
Location
South
VCDS loads.....

also using the "driver mode" button, select "individual" & set everything to "sport".....the "individual" mode is retained after each ignition switch off....where as if you use the other modes they all default back to "normal" after each ignition switch off...

PS its not the car..its to dumb down for the unskilled thicko drivers who want to feel like a "driving god"....

Yeah, it's for idiot-proofing, but this is a hell of a lot of idiot-proofing. Idiots must be of a very high quality these days. ?

I've got everything set to sport minus the noise generator. That thing was throwing me off. I check every time I drive, and the settings stay in the system. That was certainly an improvement.

Not sure what you mean by VCDS loads.
 

dosjockey

Go Kart Champion
Location
South
I may have found the replacement for the starting vibration reduction on the MK7.5's when I was playing around in OBDEleven the other night. There is a new category under the same module in a similar place called "Rough Road" with the options for Enabled and Disabled. I disabled it on mine and am testing it out currently. Initial results on wet roads were positive, it felt like my 2016 did after disabling SVR. Now that the roads here have dried up, I'm going to test it out more tonight.

That will be interesting to hear, and I'm sure very helpful for people if it proves correct.

I could see a rough road setting having an effect; as it's generally related to traction control and ABS systems; or that's been my experience on other cars, anyway.

I'll poke around the web and see if I can find anything else.

Makes sense for it to be in there somewhere, so they don't have to make a bunch of different control units for all the different vehicles of various performance levels around the world.
 
Top