Must agree Ross, the TSI does make a nice noise under heavy acceleration.

'Launching' with DSG is something I've learned since having it. You can indeed take off, even in good dry conditions at the limit of grip(a little wheelspin) with no lag (e.g getting that gap on the roundabout/junction or if you are being a hooligan, at the traffic light GP!). The technique is to floor the throttle instantly, anything less than a stamp on the pedal will give a more considered delivery. It is there if you want it.

I haven't found a way around the 'lag' when you go to accelerate again after slowing when the car is still in a high gear other than 'predictive' throttle use, which has now become second nature. Alternatively you can sort of work round it by using sport mode.

Must agree Ross, the TSI does make a nice noise under heavy acceleration.

Even more so after my £20 shop!

After reading this thread yesterday night I went out to test my Fab, mine is 5-speed manual and I didnt experience lag as you describe It, Its just that the engine gets its full torque at around 1600-1800 rpm when turbo kicks in fully and It goes away like hell! It might be that some of you have been driving atmo engines before you tried the TSI so it it strange that the power is not there instantly when you press the throttle but you have a slight delay. Greets!

After reading this thread yesterday night I went out to test my Fab, mine is 5-speed manual and I didnt experience lag as you describe It, Its just that the engine gets its full torque at around 1600-1800 rpm when turbo kicks in fully and It goes away like hell! It might be that some of you have been driving atmo engines before you tried the TSI so it it strange that the power is not there instantly when you press the throttle but you have a slight delay. Greets!

You say you did not experience any lag, but you did get a slight delay? Then we may be talking about the same thing. For me, it happens at any speed - whether in the low torque region or the high torque region. Step on the gas and nothing happens for up to about one second. Then - at the same rpm - it kicks in quite strongly. It is not a case of waiting for the engine rpm to increase.

That is the typical electronic throttle lag which unless you have experianced the responce of a (good old fashioned these days) manual controled throttle you'd not realy be aware off. It is only noticeable if you've experianced the lag free mechanical throttle of days gone by as almost every modern car is the same.

The reason for electronic throttle 'lag' is emissions. As the emission laws have become tighter, the control required to avoid unburnt/part burned fuel (hydrocarbons) has meant the throttle has to open at such a rate that allows a full burn of the fuel/air charge. An earlier control was with a double butterfly arrangement where one was controlled by throttle cable by you and the second one controlled by the car. I think this arrangement was still quite 'dirty' and can't quite deliver the control required to deliver the latest emissions requirements so it is now 'fly by wire'. The advancements in engine management seem to have enabled this to work quite well, optimising fuel delivery and ignition timing, but not perfectly, hence lag.

The reason for electronic throttle 'lag' is emissions. As the emission laws have become tighter, the control required to avoid unburnt/part burned fuel (hydrocarbons) has meant the throttle has to open at such a rate that allows a full burn of the fuel/air charge. An earlier control was with a double butterfly arrangement where one was controlled by throttle cable by you and the second one controlled by the car. I think this arrangement was still quite 'dirty' and can't quite deliver the control required to deliver the latest emissions requirements so it is now 'fly by wire'. The advancements in engine management seem to have enabled this to work quite well, optimising fuel delivery and ignition timing, but not perfectly, hence lag.

Hmm. I don't buy that. If I get good torque at a certain fuel dosage that kicks in after one second, why can I not get the same torque from the same fuel dosage without the one second delay? Remember, the engine rpm is the same. I would have thought they would be monitoring rpm and accelerator in such away that the correct dosage could be very nearly instant.

Hmm. I don't buy that. If I get good torque at a certain fuel dosage that kicks in after one second, why can I not get the same torque from the same fuel dosage without the one second delay? Remember, the engine rpm is the same. I would have thought they would be monitoring rpm and accelerator in such away that the correct dosage could be very nearly instant.

As I understand it, you have a certain throttle opening giving a certain RPM torque etc i.e a balanced throttle. You then press the throttle demanding a greater opening. I think the delay comes in it moving between these two settings increasing the fuel air charge at such a rate that can be burned cleanly. I agree you would imagine with the current engine management systems that it would deliver it instantly with no delay, perhaps the turbo complicates the issue?

In old carb engines (some even with an accelerator pump to squirt extra fuel in to compensate for the brief moment of lean mixture) and early fuel injection, the slide/butterfly responds instantly giving a greater fuel charge instantly with dirty emissions but instant acceleration. Later generations of FI (early 2000s) (double butterfly arrangements?) tended to feel very flat at the bottom end presumably because the rate of change of fuel delivery was limited as the only way of preventing emissions issues at the time. Things have moved on with more sophisticated engine management and in this case a turbo but I assume the same basic principle counts that you get acceleration from delivering increasing amounts of fuel but there is an ever tightening limit as to how quick you can do this as the emission regs become more and more stringent.

My understanding of it may be skewed or even incorrect, I am happy to be corrected

As I understand it, you have a certain throttle opening giving a certain RPM torque etc i.e a balanced throttle. You then press the throttle demanding a greater opening. I think the delay comes in it moving between these two settings increasing the fuel air charge at such a rate that can be burned cleanly. I agree you would imagine with the current engine management systems that it would deliver it instantly with no delay, perhaps the turbo complicates the issue?

In old carb engines (some even with an accelerator pump to squirt extra fuel in to compensate for the brief moment of lean mixture) and early fuel injection, the slide/butterfly responds instantly giving a greater fuel charge instantly with dirty emissions but instant acceleration. Later generations of FI (early 2000s) (double butterfly arrangements?) tended to feel very flat at the bottom end presumably because the rate of change of fuel delivery was limited as the only way of preventing emissions issues at the time. Things have moved on with more sophisticated engine management and in this case a turbo but I assume the same basic principle counts that you get acceleration from delivering increasing amounts of fuel but there is an ever tightening limit as to how quick you can do this as the emission regs become more and more stringent.

My understanding of it may be skewed or even incorrect, I am happy to be corrected

Yes, what you say makes sense. I recall this from tinkering with the SU carburettor on my old Mini 1000 (and carburettors on my Vespa and Lambretta prior to that). A squirt of petrol provides a poorly-mixed dose of fuel to act as a stop-gap until a better-mixed dose gets set up. I presume this is all now under electronic control and, as they say, should be easily switch-on-and-offable.

I do note, however, that your 1.2tsi is averaging slightly less mpg than my old 2.0i

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I do note, however, that your 1.2tsi is averaging slightly less mpg than my old 2.0i <img src='http://ww1.briskoda.net/forums/public/style_emoticons/default/emoticon-0105-wink.gif' class='bbc_emoticon' alt='' /><br />

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Ouch! Yes it isn't as good as I'd hoped but I do a lot of short journeys. On the plus side it replaced my 2L Octavia I and it gives me 25-30% better economy, the same interior space barring an inch or so, significantly more refinement, better handling and only a couple of drawbacks so I'm still happy with it