Out of curiosity I just tried LC today, Has anyone else tried this and noticed 2 things.

1) When you come off the brake pedal quickly, there is a slight delay before take off

2) I gave it a rough 0-62 time on a stopwatch which was far quicker than the quoted 0-62 time of 8.3 ish seconds.

I know there are contributing factors such as speedo inaccuracy, not quite getting the timing right but I did it twice and got 7 secs, 7.1 secs.

I do like the feature though, not sure if / when i would actually use it though, more of a gimmick i think

Edited 16 September, 201213 yr by xpower

Hows your clutch, i thought lc was meant to be used after a cooling period, nevermind the huge wear on the drivetrain

Pretty sure it also records usage to, think there is some clause on gearbox damage and warranty.

car is like 8 weeks old and done 1600 mile, I think the clutch will be fine. And that's the first / last time I will prob use it as I was just curious.

Pretty sure it also records usage to, think there is some clause on gearbox damage and warranty.

thats a bit crap isnt it, giving a car a cool feature only to punish the use of it if the gearbox goes wrong!

Hows your clutch, i thought lc was meant to be used after a cooling period, nevermind the huge wear on the drivetrain

I am not sure if I am not barking up the wrong tree but since this a DSG box, no difference to manual I operation in a way that we have normal clutch (three cluthes, 1primary and two secondaries ) and gears (separated into two groups). Launch control afaik is a glorified system of keeping the engine within the optimum rev range by slipping the clutch accordingly. You keep doing that with manual gearbox at each lights you will risk burning your clutch, same goes for DSG. Correct me if I am wrong plz.

Out of curiosity I just tried LC today, Has anyone else tried this and noticed 2 things.

1) When you come off the brake pedal quickly, there is a slight delay before take off

2) I gave it a rough 0-62 time on a stopwatch which was far quicker than the quoted 0-62 time of 8.3 ish seconds.

I know there are contributing factors such as speedo inaccuracy, not quite getting the timing right but I did it twice and got 7 secs, 7.1 secs.

I do like the feature though, not sure if / when i would actually use it though, more of a gimmick i think

Got 6.98 at GTI International last year using LC, so yes much quicker!

Pretty sure it also records usage to, think there is some clause on gearbox damage and warranty.

I was talking to a VW master tech once when we got on to DSG and whilst it probably does record usage, there is no clause in the book for the gearbox warranty and secondly, this is a feature on the car which if it was not to be used should be disabled or removed and thirdly he had never had a request from VWUK to interrogate the ECU to find this info and he had no clue where it was stored anyway!

It is a bit of an Easter Egg feature on the VRS but it is in the handbook on VW's and no mention about it invalidating anything:

Pretty sure it also records usage to, think there is some clause on gearbox damage and warranty.

That seems suspicious to me; why would the manufacturer fit a system whose excessive use would invalidate the warranty? If the machine can't take it, it shouldn't be there, surely?

Didnt realise there was a LC function. Dont think i would ever use it TBH, whats the point? Simply stamping on the throttle normally suffices. How does the traction control work when doing this? I know it says you have to switch it off but i thought the whole point of launch control was to optimise traction? Does ESP still intervene somewhat?

Can see me trying this now out of pure curiosity.

I'm sure there's something in the old shape BMW M5 user manual saying exessive use of LC can screw the gearbox.

That will be relevant to owners of old shape BMW M5's then.

Did BMW actually use the words 'screw'?

Lost in translation maybe!

george

was just pointing out that it's not just skoda that's added a function to the gear box along with a warning against using it!

Sorry i must be missing where you see that written..

Warning about using it at the wrong time i can see, but no warning about it 'screwing anything'

or 'limiting' how often you use it.

george

or 'limiting' how often you use it.

george

LC holds the clutch at its biting point at relatively high engine revs. This adds rather increased thermal load to the clutch system. DSG 7 (250Nm design torque) for small engines (1.4TSi), has dry clutch construction and despite odd gears having more torque capacity then even ones still has much less thermal load limit than DSG6 (350Nm) found in Octavias.

Thing is it is not a bottomless pit ad at some point you will smoke it if you do not allow the clutches to cool down between LC uses. Same goes for slush boxes-give me a car and within 30 mins I will burn its clutch to cinders no mater what .

It is just common sense I suppose.

No IM sorry, I had the mistaken belief this site was a place to share knowledge and experiences in the hopes it would help others.

I'm also sorry for my use of the word 'screwing' I used it as a general term to describe damaging something. What damage, I don't know I'm no mechanic.

I was merely trying to point out that it's the same case with LC on a premium car and not down to a lack of build quality with skoda.

Point taken, and i am just messing about.

I knew of plenty in manual Evo's & Scoobys getting only a few 1/4 mile starts out of clutches with manual boxes.

The point here is the Skoda have not made any 'warning' about limiting LC starts.

Common sense will limit many using it much, & many others might not have common sense.

Cant see it being a 'Warranty' avoidance issue with VAG/Skoda more than any other little tries that they pull.

george

I suspect there may be a level of misunderstanding here.

The engineers are not going to design the launch control so that the clutch is biting whilst the brake is depressed or I would consider it highly unlikely at least. I would think the hesitation that occurs when one lifts the foot off the brake proves the point. I think this is the time it takes for the electronics to recognize the brake pedal sensor and electro-mechanically engage the clutch. If it is not biting as I suspect then there would be no more wear due to that. I may be wrong of course.

I am not sure how much more clutch usage there is in general but it seems reasonable to assume that there will be some more if the car is being gunned. As the car speeds away the engine may be trying to rev in the few milliseconds between gears for instance. Even if so though, that is probably not overly significant as by that point the DSG is just changing gears i.e., the business-as-usual function of the gearbox and clutch unrelated to the use of launch control.

There will of course be a more robust use of the clutch in first gear but probably far better controlled than most drivers are able to achieve in a manual so even there the wear is unlikely to be worse than that for any lead-footed driver in a manual.

Finally, I think I am right in saying that the DSG clutch, in the vRS at least, is more over-specified than the manual clutch. I would assume then that, for a standard level of tune at least, it is more than capable of dealing with the odd bout of enthusiasm?

What I read about DSGs produced by VAG was very clear and believe it is in the manual, that you should not stay in drive position even on red lights and move the stick to N. As I have not read the manual itself I cannot be sure about that one but I am pretty sure about the fact that it is at biting point when in drive and break pedal is depressed. Then depending on speed and position of the accelerator pedal DSG ECU regulates the pressure on the plates (in manual position of your clutch pedal) and you drive away either rather rapidly or at a more sedated pace. One more thing about that ECU. As it uses fuzzy logic engine to predict gear changes it leads from your driving style and adapts its behaviour accordingly. So if you drive like a geriatric sloth in hunt of those elusive mpgs it will develop different shifting patters to a boy race with bad case of a permanent itch of the right foot only relieved by rubbing it hard against the accelerator pedal. I just wonder how big such differences would be?

Btw, there is no throttle position change between upshifts so revving. The next gear is already turning at the engine speed waiting for the clutches to switch over. Total time there is no power to the wheels is 8ms - the same system is used in F1 cars, it is only a tad smaller (100mm in diameter) weighs 70 times less (1kg) and shifts in 5ms while being able to transfer circa 750 bhp.

Jabazumo,

Do not expect the Octavia vRS & Fabia vRS DSG's to act the same,

the Fabia does not have Launch Control.

No car should being sitting with it in Drive at traffic lights, not for the gearbox,

but in line with the Highway Code.( Stop & apply the Hand Brake, chose Neutral and release the foot brake so as not to dazzle motorists or cyclists behind you.)

We know how that is Ignored.

We also know thats not practical, but for lengthy stops we know what we should do.

There are Drivers in cars with DSG and Hill Hold Control (HHC) that sit at lights or Junctions with their foot on the brake.

Its all a choice and style of driving.

Personally i never could use Launch Control.

Not because i wouldnt, just i cant, because i only have one foot! A Hand control brake would be required.

george

Btw, there is no throttle position change between upshifts so revving. The next gear is already turning at the engine speed waiting for the clutches to switch over. Total time there is no power to the wheels is 8ms - the same system is used in F1 cars, it is only a tad smaller (100mm in diameter) weighs 70 times less (1kg) and shifts in 5ms while being able to transfer circa 750 bhp.

Are we sure this 8ms is right?? Is it not 80ms or something. 8ms seems far too fast. Plus i can feel the gearchange in mine. I doubt i would be able to feel a 8ms change, wouldnt have thought the human body was capable of this. Is the bilnk of en eye not 250ms or something?

Are we sure this 8ms is right?? Is it not 80ms or something. 8ms seems far too fast. Plus i can feel the gearchange in mine. I doubt i would be able to feel a 8ms change, wouldnt have thought the human body was capable of this. Is the bilnk of en eye not 250ms or something?

Taken from wikipedia,

"The internal combustion engine drives two clutch packs.The outer clutch pack drives gears 1, 3, 5 (and 7 when fitted), and reverse — the outer clutch pack has a larger diameter compared to the inner clutch, and can therefore handle greater torque loadings. The inner clutch pack drives gears 2, 4, and 6. Instead of a standard large dry single-plate clutch, each clutch pack for the six-speed DSG is a collection of four small wet interleaved clutch plates (similar to a motorcycle wet multi-plate clutch). Due to space constraints, the two clutch assemblies are concentric, and the shafts within the gearbox are hollow and also concentric^. Because the alternate clutch pack's gear-sets can be pre-selected(predictive shifts enabled via the 'unused' section of the gearbox), un-powered time while shifting is avoided because the transmission of torque is simply switched from one clutch-pack to the other. This means that the DSG takes only about 8 milliseconds to upshift.^[3][4] In comparison, the sequential manual transmission (SMT) in the Ferrari F430 Scuderia takes 60 milliseconds to shift,^[18] or 150 milliseconds in the Ferrari Enzo.^[3] The quoted time for upshifts is the time the wheels are completely non-powered."

Taken from wikipedia,

"The internal combustion engine drives two clutch packs.The outer clutch pack drives gears 1, 3, 5 (and 7 when fitted), and reverse — the outer clutch pack has a larger diameter compared to the inner clutch, and can therefore handle greater torque loadings. The inner clutch pack drives gears 2, 4, and 6. Instead of a standard large dry single-plate clutch, each clutch pack for the six-speed DSG is a collection of four small wet interleaved clutch plates (similar to a motorcycle wet multi-plate clutch). Due to space constraints, the two clutch assemblies are concentric, and the shafts within the gearbox are hollow and also concentric^. Because the alternate clutch pack's gear-sets can be pre-selected(predictive shifts enabled via the 'unused' section of the gearbox), un-powered time while shifting is avoided because the transmission of torque is simply switched from one clutch-pack to the other. This means that the DSG takes only about 8 milliseconds to upshift.^[3][4] In comparison, the sequential manual transmission (SMT) in the Ferrari F430 Scuderia takes 60 milliseconds to shift,^[18] or 150 milliseconds in the Ferrari Enzo.^[3] The quoted time for upshifts is the time the wheels are completely non-powered."

Nuff said. Sounds very factual. Although it does say " from wikipedia " which kind of makes the rest of the text unreliable. Your probably right though as it kinda makes sense that a dual clutch should be faster than an automated manual with single clutch.

Nuff said. Sounds very factual. Although it does say " from wikipedia " which kind of makes the rest of the text unreliable. Your probably right though as it kinda makes sense that a dual clutch should be faster than an automated manual with single clutch.

Downshifts are no way near as fast as the ECU blips the throttle to match revs but I believe its been rated at around 100ms. They are not so good when you select a gear that the ECU/Gearbox did not anticipate and I think this type of shift can be around 1100ms.

Your probably right about the wikipedia bit tho :think:

Edited 18 September, 201213 yr by Fitz323

Nuff said. Sounds very factual. Although it does say " from wikipedia " which kind of makes the rest of the text unreliable. Your probably right though as it kinda makes sense that a dual clutch should be faster than an automated manual with single clutch.

Well you can follow the references from Wikipedia for further more reliable sources:

http://cars.about.com/od/thingsyouneedtoknow/a/ag_howDSGworks.htm

http://www.autozine.org/technical_school/gearbox/tech_gear_manual.htm#Twin-Clutch