[noopster]

THis thread is all over the place! From turbo lag to clutches that need overhauling and now rubberband effect on a CVT. Perhaps this is better suited in "Shifting Gears" rather than the technical section!

[vina]

Originally Posted by noopster

THis thread is all over the place! From turbo lag to clutches that need overhauling and now rubberband effect on a CVT. Perhaps this is better suited in "Shifting Gears" rather than the technical section!

I beg to differ.

The title is Turbo Lag 101 - anything related to Turbo Lag can can and should be discussed.

This includes how to handle turbo-lag (clutch slipping) and what other effects feel the same to the driver (rubber-band effect).

[ph03n!x]

Originally Posted by D33-PAC

When I stepped on the accelerator (I was feathering the accelerator), the car initially went nowhere even though I was well above idle. There was a sense of motionlessness, and I could tell the engine was well above idle because I could hear the engine note change from idle.

Ummm... did you release the clutch fully? If you did AND this happened, the clutch is slipping. And not, this is not turbo-lag

[D33-PAC]

Originally Posted by ph03n!x

Ummm... did you release the clutch fully? If you did AND this happened, the clutch is slipping. And not, this is not turbo-lag

Yessir if I can remember correctly the clutch was released. I've come to the conclusion something might be wrong with the car. Good thing it's not my car LOL.

[SS-Traveller]

Originally Posted by dhanushs

A slight change is there. The turbocharger does not spin until a certain rpm.

I beg to disagree, but a turbocharger spins continuously unlike a supercharger, as long as the engine is running; at low / close-to-idle rpms the revs are not enough to produce sufficient compression of the intake air to make any difference as compared to a NA engine.

Originally Posted by dhanushs

On the highway, do not rev above the power band.

Why not? What difference would it make to a turbocharged engine?

Originally Posted by vina

The title is Turbo Lag 101 - anything related to Turbo Lag can can and should be discussed.

This includes how to handle turbo-lag (clutch slipping) and what other effects feel the same to the driver (rubber-band effect).

+1. Let the discussions spool up!

[Sutripta]

Originally Posted by noopster

THis thread is all over the place! From turbo lag to clutches that need overhauling and now rubberband effect on a CVT. Perhaps this is better suited in "Shifting Gears" rather than the technical section!

http://www.team-bhp.com/forum/hatchb...ml#post2245975
and
http://www.team-bhp.com/forum/hatchb...ml#post2310263

Regards
Sutripta

[dhanushs]

Originally Posted by SS-Traveller

I beg to disagree, but a turbocharger spins continuously unlike a supercharger, as long as the engine is running; at low / close-to-idle rpms the revs are not enough to produce sufficient compression of the intake air to make any difference as compared to a NA engine.

You are right. I stand corrected!.

Butt, doesn't superchargers too spin at all times?.

Originally Posted by SS-Traveller

Why not? What difference would it make to a turbocharged engine?

1. Vina was migrating from a petrol engine to a diesel engine. I believe diesel engines wear and tear at high rpm's are much higher than petrol engines, due to higher compression.
2. There is no point in revving it above the power band. Atleast me, have never revved a diesel all the way up to its rev limiter. I really havent felt like.

[noopster]

Originally Posted by vina

I beg to differ.

The title is Turbo Lag 101 - anything related to Turbo Lag can can and should be discussed.

This includes how to handle turbo-lag (clutch slipping) and what other effects feel the same to the driver (rubber-band effect).

Sorry vina, but clutch slippage and CVT rubberbanding has nothing to do with turbo lag. For one, these are observed in vehicles with or without turbo. But we should definitely use this thread to discuss everything about Turbo Lag, agree.

[SS-Traveller]

Originally Posted by dhanushs

Butt, doesn't superchargers too spin at all times?.

Not until they are switched on through an electric clutch or similar arrangement, or unless they are fitted to run all the time. Running them continuously is optional.

Originally Posted by dhanushs

1. Vina was migrating from a petrol engine to a diesel engine. I believe diesel engines wear and tear at high rpm's are much higher than petrol engines, due to higher compression.
2. There is no point in revving it above the power band. Atleast me, have never revved a diesel all the way up to its rev limiter. I really havent felt like.

Ok - I was under the impression that you meant it might harm a turbocharger. But then, revving a diesel to its limiter is in no way any more harmful than doing the same to a petrol engine.

[vina]

Originally Posted by noopster

Sorry vina, but clutch slippage and CVT rubberbanding has nothing to do with turbo lag. For one, these are observed in vehicles with or without turbo. But we should definitely use this thread to discuss everything about Turbo Lag, agree.

Sure they do:

rubber banding feels similar to turbo lag (so should be discussed in a Turbo Lag 101 to show what is not turbo lag but feels like it ), and clutch slipping is an important technique for somebody trying to start a fully-loaded vehicle on an incline that has turbo lag and hence relatively little power at low rpm.

thanks for the thumbs up by the way - and I'm a newbie driver so I have only to learn from you guys.

[dhanushs]

Originally Posted by SS-Traveller

Not until they are switched on through an electric clutch or similar arrangement, or unless they are fitted to run all the time. Running them continuously is optional.

I have not come across a supercharged car in my life, but I believe most superchargers are mechanically driven(always spinning)?.

Also, could you please enlighten me about which cars sport electric clutch or similar arrangement for driving a supercharger, and what/how do they turn ON?, and the deciding factors?.

Originally Posted by SS-Traveller

... But then, revving a diesel to its limiter is in no way any more harmful than doing the same to a petrol engine.

Well, I thought the forces that act on the piston face are much higher than the petrol's?. And wouldn't that mean a much higher stress on high rpm's?.


Not practically very relevant, but I think, another reason for not high revving a diesel is the slow burn rate of the fuel, but I guess, these engines already have lower rev limiter than the petrols.

[i<3turbo]

No one mentioned turbo lag is also based on the size of the turbo. These cars mentioned all have small turbo's which start to spool up around 1200 and hit about full boost around 2000. Twin turbo's are actually to take away the lag. This is when it is sequential which means one turbo is slightly smalled than the other. Its basically a prespool for the bigger turbo to kick in so there is no lag.

[vina]

Originally Posted by i<3turbo

No one mentioned turbo lag is also based on the size of the turbo. These cars mentioned all have small turbo's which start to spool up around 1200 and hit about full boost around 2000. Twin turbo's are actually to take away the lag. This is when it is sequential which means one turbo is slightly smalled than the other. Its basically a prespool for the bigger turbo to kick in so there is no lag.

Isn't VGT similar to what you are saying (just asking)/

Also is there an easy mod that can be used to reduce the turbo-lag?

[volkman10]

Turbo lag, as of now, cannot be eliminated but the effect could be reduced.
See link on PBS(Pneumatic Booster System) that is being developed for commercial vehicles for elimination of the turbo lag.

Cheers!

http://www.knorr-bremse.de/media/en/...mzt06I2009.pdf

[vina]

Is there some kind of a "reverse turbo lag" too?

For past few days I have noticed something:

When I'm driving my Figo at 1300rpm it generates a lot of power. Now if I drive for some time (30 seconds) at that rpm, and then shift up, the rpm drops below 1000 but the power doesn't drop much for several seconds.

On the other hand if I'm coming from a low rpm (say roughly 700, 800) into 1000 rpm, it takes several seconds before power develops.