Twincharger 7DSG - Selects higher gear than it should. Thoughts?

[logger]

When the Twincharger 7DSG is operated in "D", it will readily run at lower revs and a higher gear than most of us are used to. As anyone who has one will know it will climb a hill in 7th gear at around 60kmh and 1300rpm.

There is a notion that with the Twincharger 7DSG operates at low revs in a high gear under load "..you are putting too much strain on it and that its bad for the engine."

At the moment I found the car up gears too early..Upgear too early like car driving 55km/h in D7 around 1200rpm, I can hear the engine clonking, not sure if that the right term. Sound like if you starting a manual in second instead of first.

That is the engine labouring, it's basically the engine crying for help because you're putting too much strain on it. It's bad for the engine in the long term.

Thats what I think too, it reminds me of my early days of driving a manual, where putting into 5th instead of 3rd or 4th instead of 2rd.

Not sure if other 7DSG drivers experiencing the same issue of having a higher gear than what it should be. At the moment I either drive it in S or if i see a hill coming, i would accelerate more, forcing the DSG to downgear(s)

I disagree with this notion for the following reasons:

1) you are applying anochronistic thinking to a a cutting edge piece of technology. We are not talking about a 20 year old holden with a manual transmission.

2) I find it hard so believe that VW would design a car with a highly advanced powerplant and automatic transmission and then forget to configure it, so that in its most automatic idiot proof setting "D", it will allow the driver damage it when driving uphill in a liesurely manner .

3)The ECU on the Twincharger and the 7DSG's Mechatronics unit will have all sorts of sensor imputs. I do not believe the designers would allow them to so readily operate in a regime where it could damage itself.

4) The engine is said to develop maximum boost (not torque or power) at a meagre 1500rpm so surely it is designed to run under load in this regime. see Inside VWs twincharger

5) My take on it is, the noise you are hearing is a characteristic of the Twincharger + 7DSG. It might be the supercharger or just the engine itself under load, but I reckon it is quite acceptable and I am happy to drive my car in this range until someone can give me a good reason not to.

As always - happy to proven wrong. Can someone with specific engineering knowledge of these engines clarify this for us? Thanks...

[sillygogo]

Logger:

I am not really sure what is the noise i am hearing. I believe it is because the DSG is in a higher gear than it should be because, the engine vibrates, and "sounds like" in the wrong gear. That was how i found the sunvisor was lose. She is smooth and sweet once it is in to 5 or 6.

I don't think it does any long term damages, however i do believe it is not running as efficent as it should be.

[mickofoz]

It's all perception. I currently drive a Polo GTI. I have always "driven" the car the way I thought it should be driven until I saw a video on the VW German website on how to drive a manual VW for max fuel economy. Basically if you follow VW's recommendations, you will end up in 4th gear by the time you hit 40km/h. I tried it and ended up with a 2l/100km saving. Sure, I thought the engine sounds like it is about stall, but after a while, it started to sound normal. Like I said, what we "THINK" it should sound like, is often not the case at all.

[Grover]

Yes the new VW 7Sp DSG does take "short shifting" to the extreme and while this may result in a fuel saving I do find myself constantly shifting to "Sport" mode for normal traffic light starts and some slow speed corners before shifting to normal "D" mode once it gets over about 30Kph. It just feels better. I think that the right config for me would be to just raise the rev range slightly for the 2 and 3 gear shifts.

That said, "Sports" mode is too much for normal driving cruising.

[pologti18t]

Best fuel efficiency in a petrol engine is moderate to low revs and throttle opened as much as possible (less pumping losses).

Essentially this means you need to accelerate with lots of throttle but upshift early. This is exactly what the DSG seems to be doing. Keeping the maximum load on the engine.

[Dub_Star_V6]

Buy a manual. Problem solved.

[Stoney!]

I'd be inclined to say the noises being heard are the injectors rattling away at low RPM, Direct injection is known for it's noisy clatter on idle and under load. Whilst it's probably not the nicest sound, I highly doubt its doing any damage, that said is there anyone that can Flash a DSG, because 7th in local speed limits sounds a bit outrageous to me.

I to have also noticed keeping the revs up on the 118tsi uses less fuel then plonking down through the gears and climbing hills at 1700rpm with the supercharger howling, And I often wondered being a manual driver how the DSG copes in this area, whether the program is intuitive enough to keep the engine in its power and economy sweet spot on hills of around 2200rpm. I got my answer now and clearly it's no.

Stoney!

[Ryan_R]

If I'm in a hilly area with a low speed limit (i.e. 60) the DSG will often change down as if it wants me to boot it up the hill (I can nearly hear it saying "c'mon slow poke" - actually that's probably me saying it to the person in front). In such cases I switch to manual and change gears between 4-6 to keep things smoother.

[RW1]

This may be of interest....

As part of some misfire investigations I've been doing, I re-gapped the factory fitted spark plugs from 0.91mm (36 thou) to 0.79 (31 thou) [VW Maintenance Manual Spec is 0.8mm to 0.9mm]. VW plugs supplied as spares are also gapped at 0.91mm.

The effect has been a smoother engine at lower rpm. As a consequence the 7 speed DSG has been better at handling the gears in the region of 1,700rpm - 2,100rpm. Where in the past I would get gear change down on some hills, the car now pulls up the same hill inclines smoothly without dropping a gear in most instances. The engine is quieter too, both at start-up with that diesel noise period initially and also while driving - almost silent inside the cabin. Gear changes are generally smoother across the gears and engine rpm's and the first gear lurching has gone.

[Brian]

This may be of interest....

As part of some misfire investigations I've been doing, I re-gapped the factory fitted spark plugs from 0.91mm (36 thou) to 0.79 (31 thou) [VW Maintenance Manual Spec is 0.8mm to 0.9mm]. VW plugs supplied as spares are also gapped at 0.91mm.

The effect has been a smoother engine at lower rpm. As a consequence the 7 speed DSG has been better at handling the gears in the region of 1,700rpm - 2,100rpm. Where in the past I would get gear change down on some hills, the car now pulls up the same hill inclines smoothly without dropping a gear in most instances. The engine is quieter too, both at start-up with that diesel noise period initially and also while driving - almost silent inside the cabin. Gear changes are generally smoother across the gears and engine rpm's and the first gear lurching has gone.

Hows it go at higher revs? eg 5k +.
Years ago I played with spark plug gaps endlessly.
General result was:
Smaller gaps = easier starting and smoother running from idle to around 4k revs but with some misfires towards redline (~ 6k in those days)
Larger gaps = u guessed it - harder starting and poorer low end performance but clean and crisp at the top end.
Mind you Im talking non ECU controlled cars here - just plain old dizzy and carbie. You could end up with thousands of combos by playing with the timing as well..