actually the turbo is always spinning la...
it dont stop, then spin, then stop...

question u should ask is that, will the turbo hold enough boost to give the specified power...

part of my discussion in another thread...
i copy and paste here...

what u mentioned is very simplified for layman understanding but thats not actually how it will happen...

Twincharging's largest benefit is to overcome turbo lag.

Supercharger start when you start your engine, at 3500rpm turbocharger is fully take over.

supercharger has boost level too...
but supercharger is more responsive as it is belt/pulley drawn directly from the engine crankshaft as opposed to exhaust gas driven turbo charger...

that is why i say cute_boboi description is for layman... easier for people who dont understand the mechanics of these devices, people like you....

if u explore further, u will see that i mentioned the supercharger wont re-engage if ur rpm goes below 3500 rpm provided the turbo holds enough boost to drive the car...

u need to understand the whole picture on how it works...
not just brouchere based as those are for layman.... to help them understand in general why this engine has 2 method of charging...

The point is, no matter what, from standstill, the supercharger will try to engage first from low rpm ~1700-3300rpm (I can't recall exact figure, so just quoting from sky). The turbo will only kick in (or enough boost, or engage, or whatever) from 2800rpm upwards.

So, if daily drive as per the earlier question, what is better, as I said, is driver driving preference or style.
If daily normal drive, most will rev within 1k-3k rpm.
Only some will rev 5-7k non-stop from door-to-door, then obviously they will be able to utilise the turbo frequently.

Therefore, to answer the earlier question, the super-charger is helpful for the low-rpm range. As the turbo never has chance to kick in.

yup, u are correct to a certain extend...

but to correct your turbo dont have a chance to "kick" in part...

if u rev/drive below the supercharger cut off rate, turbo will still build up boost but at a much slower rate...

but once turbo has enough boost to sustain, even if u do not rev above the supercharger cut off rpm, the super charger will be disengaged...
super charger will re-engage by the ECU only if the turbo boost level drops to a pre-determined level that the ECU/system...

Tweaked my PGTI a bit for added responsiveness in the mid range -- didn't need higher top end. So far, quite happy with the results

So, in general twincharged is better than turbocharged, especially at low rev. Wouldn't it better if GTI also have twincharged? Wats d reason vw is not doing this?Too expensive?
I m wondering......

Ok, let's go technical (in layman style ). If driving from door-to-door, the RPM never exceed 3k (or 2.5k for very light foot) RPM, with traffic lights every 500m , for a distance of 5-10km.
i.e. drive up and cruise at 1.8k RPM at highest gear at ~70-80km/h

Will the turbo ever has chance to kick in ?

I wouldn't say it is better, again, driver preference driving style

TSI twincharger engine is more like a technology break-through and showcase for the mass public at that time. VW did it, win several engine of the year award, etc. Been there, done that kind of thing.
Like you, I can't think or recall the reason why it was abandon. Expensive is a word that always ring around.

I still think this is the best engine (not gearbox) for the 1.0L-1.5L range.

Not sure about the latest Ford engine 1.0L (999cc) eco-boost as I think haven't reach our ground yet.

COST...


first thing first... turbo dont kick in... it spins all the time.. it is not on/off kinda thing...

the kick people always mistaken is the pulling power of the turbo once it is in full boost...
people always call those feeling as kick or something along the line, hence the "kick" word sort of stuck...

as i have mentioned before... turbo is exhaust gas driven... once u start the engine, there is exhaust gas generated that has to go thru the turbo unit first before exiting the vehicle... so in this sense, the moment u start the engine, the exhaust gas will start to spin the turbo...

general issue here is, the exhaust gas generated dont have enough force to spin the turbo to full boost... in order to spin the turbo to full boost, u need load, which means u need to get moving... depending on how rapid u move, the exhaust gas generated under load will spin the turbo faster... (bigger turbo needs more load to reach full boost)..

so taking your scenario, yes the turbo will spin up to full boost too, but it will take much longer time (even though u did not reach the supercharger cut-off RPM) because the exhaust gas generated by the engine load is not as strong as full throttle/heavier throttle...
even if u settle into a cruise at 1.8k rpm at 70-80 kmh, there is constant exhaust gas generated into the turbo unit that will slowly but surely spin it to full boost...

and again i repeat, once the ECU detects there is enough boost to sustain the momentum, the supercharger will be disengaged regardless u are below 3.5k rpm or not and only re-engaged if the ECU detects that the boost is below certain threshold..

good enough?

Tks cute_boboi.
I found an old news from internet, to phase out twincharged.
http://www.caradvice.com.au/99056/volkswag...sed-out-report/

Tks kcng
How about turbocharged car? Meaning engine will be under power before the turbo engine spin to the full boost?

Good Hope is informative for other readers.

Thanks for refreshing my memory

Yes, even if full pedal to metal, it takes split seconds for the pedal signal to ECU, fuel mixture, injection, 4-stroke, combustion, and finally the exhaust to go out to turn the turbine .
That's turbo lag.

what i have explained is the same for all cars with turbo, regardless with an extra super charger or not...


as wat cute_boboi mentioned below...

pisang,
just to add on, bigger turbo suffers more lag but gives much more power once up to boost... and possibly might be able to maintain boost longer...

thanks again.
may i ask if size of turbo is propotional to the size of the engine cc?
turbo in 1.8 liters is bigger than turbo in 1.4 liters?

by re-mapping?

nope... it can be the same turbo size...
its the ECU mapping that determine how much boost will the turbo generate...

of course there is a limit to how much boost will one turbo hold...

Just some random news I came across today. http://www.motortrader.com.my/news/managem...group-malaysia/

VWM change of management ppl. Hope this will further improve their customer service in Malaysia.

thanks

i've got one more thing which i don't quite understand.

For 1.4 TSI, it can get max output about 160PS, max torque about 240Nm.
For 1.8 TSI @ passat, cc, max output about same 160PS, max torque 250Nm.

Comparing these two, 1.4 liter engine can produce almost similar output as 1.8 liter engine.
why not VW put the 1.4 liter engine at Passat where the performance is almost similar.

could it be Passat 1.8 engine is relatively an older engine compare with the new 1.4 ?
From costing wise, smaller engine should be cheaper ,correct?

nope
the twincharge engine is more expensive n complex... compared to just a turbo...