1.6 fsi driving style

thestable

Member
I’ve seen this “driving style” mentioned a few times on here and other Audi forums with regards to this car.

What do they mean?

And also... why are people so keen to change wipers on their A2’s?

Cheers


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I’ve seen this “driving style” mentioned a few times on here and other Audi forums with regards to this car.

What do they mean?

And also... why are people so keen to change wipers on their A2’s?

Cheers


Sent from my iPhone using Tapatalk

The FSI has effectively two stages of power, low down the flaps reduce the volume of air that flows into the cylinders because the large bore does not allow a fast enough flow of air. When the revs climb the speed of the incoming air increases and so it can handle a wider bore and so the flaps open.

The theory being that you can get "normal" performance and economy at lower revs and more power when you use higher revs.

That means that if you are "poodling" around town and then floor the throttle, the revs rise slowly until 3000 or so and then the car performs very well.

So when driving a diesel with loads of torque you do not have to rev the engine highly, on a FSI if you want performance you really do rev it highly up to around 6000 RPM if you want to have fun (on safe roads or tracks of course)

The driving style of the TDI is very different and so if you are used to that and then switch to a FSI you do need to rev it more than the diesel.

As for the wiper, the "Floppy" wiper is MUCH better than the wipers with a metal frame, they are quieter and work much better.

Steve B
 
The FSI has effectively two stages of power, low down the flaps reduce the volume of air that flows into the cylinders because the large bore does not allow a fast enough flow of air. When the revs climb the speed of the incoming air increases and so it can handle a wider bore and so the flaps open.

The theory being that you can get "normal" performance and economy at lower revs and more power when you use higher revs.

That means that if you are "poodling" around town and then floor the throttle, the revs rise slowly until 3000 or so and then the car performs very well.

So when driving a diesel with loads of torque you do not have to rev the engine highly, on a FSI if you want performance you really do rev it highly up to around 6000 RPM if you want to have fun (on safe roads or tracks of course)

The driving style of the TDI is very different and so if you are used to that and then switch to a FSI you do need to rev it more than the diesel.

As for the wiper, the "Floppy" wiper is MUCH better than the wipers with a metal frame, they are quieter and work much better.

Steve B

Thanks Steve!

Very helpful to know. I wonder if this driving style could be partly the reason for my loss of power when climbing through the revs. And is it just how the engine is...

I found a video on YouTube on another car which is exactly what’s happening on mine.

https://www.youtube.com/watch?v=MOx6XXlI1FY


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Steve has answered your question well, but I am a FSI owner of 8 years experience and will chip in more from a practical laymans point of view.

At low revs below when the flaps have not opened (2800rpm so I am told but in practice 3000/3200rpm before it you notice an effect) the FSI accelerates slowly but quietly. In everyday terms this means for example starting from stationary at lights or low speed out of a roundabout other quite modest vehicles make the FSI look pedestrian as they shoot ahead and the FSI lags behind. Flat as a pancake springs to mind - I wish it could be remapped to open the flaps at 2000rpm!! In my mind Audi got it wrong with 2800rpm too high but I suppose this depends on the design of the engine and not some simple ecu code "IF rpm=2800 open flaps and increase injector flow" Once the flaps open the picture changes and you begin to catch up and as the revs build you can hold your own and outpace if it is safe to do so but the noise level has increased substantially.

No doubt guys on here have raced A2 variants on test tracks and know the answer but my guess is if say a TDI and FSI entered a longish motorway slip road and both drivers tried, the TDI would shoot ahead but by the the time you join the motorway it would be neck and neck and a mile down the road the TDI would be receding in the FSI rear mirror. [I bet that elicits some comment!]. Of course this is not sensible responsible everyday driving and the previous scenario academic as most driving is urban 30/40/50mph and where would admit from what I read the TDI edges the argument, and maybe the FSI for motorway driving.

Lots more I could say but to get a FSI to move you have to get to the higher rev range and not be afraid to use it - the FSI does not seem to mind but I do.

Andy
 
Sorry forgot to mention your video. IF your FSI is like the video something is wrong. It's difficult to say as it not clear what gears are engaged but assuming the driver is 'trying' with foot hard down on accelerator the revs and speed should of course rise steadily and quickly. By the end of that video I am sure I would be exceeding the speed limit and maybe an instant ban! I can say quite definitely that my FSI cruises in fifth at 70mph with 3200rpm if that is any help.

It's late, goodnight.

Andy
 
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Sorry forgot to mention your video. IF your FSI is like the video something is wrong. It's difficult to say as it not clear what gears are engaged but assuming the driver is 'trying' with foot hard down on accelerator the revs and speed should of course rise steadily and quickly. By the end of that video I am sure I would be exceeding the speed limit and maybe an instant ban! I can say quite definitely that my FSI cruises at 70mph with 3200rpm if that is any help.

It's late, goodnight.

Andy

Sorry andy. I should have been clearer.

The hesitation that happens. Quite late in the clip I showed, happens in gears 2 and up in my car it seems. However if I am really gentle in accelerating it doesn’t do it that I have noticed. (I’ve only driven it twice since Tuesday and happens When engine is warmed up which is why I didn’t notice in test drive. After the hesitation it goes faster no worries. It can get up to 70 also no worries. It’s just that the acceleration curve I have come to expect from every car I have ever driven does not happen in this car. It’s like you put your foot hard to the floor and it rises. Plateaus and then ignites and rises again.




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Andy's synopsis on the FSIs drive is excellent. I can also relate to the 2800rpm range, but I am firmly in the same camp as thestable with hesitation before full on acceleration. Rather than a nice linear acceleration curve which I would prefer, it has enough low down torque to make for short shifting, but push the the throttle to the floor and I also get - torque, hesitation, bhp. I do think there is a delay in the flaps opening if this is even remotely possible.

As I love the car and don't have a pile of money to throw at the engine, I drive around this. It is not noticeable when short shifting at circa 3000rpm or below and for spirited overtakes I pop it into the bhp range say 4000rpm and above. Thereby avoiding the 3000 to 4000rpm band if absolute speed and urgency is needed. I have found that injector cleaner helps significantly smooth out the hesitation and I would recommend this. I now use one-shot Redex in every fill up.

I may invest in full on investigative work someday, but with an injector cleaner additive, the response and engine note is much improved and pleasant as I say.

This doesn't really help you per se, but take solace that you are not alone.

Cheers,

Darren
 
The acceleration should rise steadily without hesitation. The hesitation is a symptom of problems with either the injection or the ignition seems to affect most of the 1.6 Fsi engines.
 
I don't know a lot about petrol engines at all, but my understanding was/is that the manifold flaps are not there to do the job of the throttle body (limiting the flow of air) but to cause the air entering the cylinders to swirl, hence why they're known as swirl flaps. Given that the petrol is introduced directly into the cylinders (a la the TDI), the swirl flaps help the vaporous petrol to mix properly with the incoming air. As revs build, the swirl flaps change their orientation not to increase air flow but to alter the 'degree of swirl'. I could be miles wide of the mark, but I cannot understand why Audi would effectively have two components performing the job of the throttle body.

Whilst I agree that you need to rev the FSI in order to unleash its beans, I think the notion of the FSI having two different 'levels of power' has arisen simply because so many of them are, in one way or another, broken. Almost every FSI available on the open market will have something wrong with it, leading us to conclude that these quirks are just part of its character. I agree with Steaman; the acceleration should rise steadily without hesitation. On the rare occasions when I've driven a properly sorted FSI without its engine management light on, this is how they perform.

Cheers,

Tom
 
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I agree with both of you. In my case, I should have perhaps elaborated. It feels hesitant rather than is a notable issue with the revs floundering. It is probably more injector related, build up of carbon perhaps, which is why injector additives improve things. Also, I have a particularly low mileage lightly used car, which won't help to burn off deposits either. This is me being particularly ruthless too, it is not a fundamentally poor drive either, but could be improved on.
 
Your correct Timmus, the swirl flaps or intake manifold flaps as Bosch call them has the following purpose:

The intake manifold flap closes the lower duct in the cylinder head. The intake air flows at a faster rate and tumbles into the cylinders via the upper duct.

In the cylinder, the tumble motion of the air is increased by the special shape of the piston crown.

My Fsi had the same hesitation symptom when I bought it and I started with:

  • injection cleaning
  • Replacing the sparks and coils. It made some improvements but I could still notice some hesitation.
  • Next step was to replace the low pressure fuel pump and pressure regulator without any improvement.
  • Finally I removed the intake manifold and dismantled it and cleaned it with "oven cleaner", replaced the injectors, high pressure valve and high pressure sensor, all at the same time, and finally no more hesitation.
  • I got the replaced injectors controlled, the flow measured, cleaned and measured again. They were faultless from start and not the root cause.
 
Yes
effectively the intake ports are too large to have good air flow speeds at low revs and so the flaps reduce the effective size of the intake port to allow for that. It therefore increases the speed and therefore swirl.

I short you need smaller port sizes at lower revs and larger ones at high revs. Rather than increase in size at higher revs the flaps reduce the ports at lower revs.

Quite clever really and it works well when the flap arm is not broken.

So with an FSI you do need higher revs if you want good acceleration.

I have a journey every Saturday morning to play golf and the roads are perfect for an FSI and it was a very enjoyable drive today, but hitting 5 or 6 thousand revs just seems too much when you are used to a Tdi, but it really isn’t.

Steve B
 
Your correct Timmus, the swirl flaps or intake manifold flaps as Bosch call them has the following purpose:

The intake manifold flap closes the lower duct in the cylinder head. The intake air flows at a faster rate and tumbles into the cylinders via the upper duct.

In the cylinder, the tumble motion of the air is increased by the special shape of the piston crown.

My Fsi had the same hesitation symptom when I bought it and I started with:

  • injection cleaning
  • Replacing the sparks and coils. It made some improvements but I could still notice some hesitation.
  • Next step was to replace the low pressure fuel pump and pressure regulator without any improvement.
  • Finally I removed the intake manifold and dismantled it and cleaned it with "oven cleaner", replaced the injectors, high pressure valve and high pressure sensor, all at the same time, and finally no more hesitation.
  • I got the replaced injectors controlled, the flow measured, cleaned and measured again. They were faultless from start and not the root cause.

I shall be doing exactly this route. Just put some injector cleaner in and will be taking her for a drive tomorrow to see how she performs. Next steps will be full service. New plugs and coils. And take it from there.

I shall also be filling up with 98ron from now on and using a cleaner regularly if this works so well.


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  • Finally I removed the intake manifold and dismantled it and cleaned it with "oven cleaner", replaced the injectors, high pressure valve and high pressure sensor, all at the same time, and finally no more hesitation.
  • I got the replaced injectors controlled, the flow measured, cleaned and measured again. They were faultless from start and not the root cause.
So, what's your opinion about the culprit ?
 
I dont know, but it should be the high pressure valve or the high pressure sensor. I dought cleaning of the manifold would give such improvement.
The behavor indicated fuel starvation and that I believe either of those could be the root cause.
 
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