[RPM90]

Originally Posted by Bimmerista

RPM90: the 335 engine will in fact, once the grade of fuel is upgraded here, be 15% more fuel efficient than the 3.0 non-turbo engine-this from Euro stats, and thanks to the more efficient use of the DI in combo with the turbo.

I have read the thread with great interest, but I am afraid that everyone is right. Ultimately, turbos are a very effective way to increase power and torque without increasing displacement. However, there is turbo lag-which is not a relative but an absolute (because the lag is in relation to the engine itself and depends upon the rpm band) and it is noticeable in every turbo engine. The jury is still out on the 335, we will see.

I personally do enjoy the performance that turbos permit, but do not like the lag. Engines without turbo which make high horsepower to litre ratios are indeed very sophisticated, and those who do so starting at lower rpms without turbo are the epitomy of sophistication and refinement (which is not easy, ask any S2000 or Rx8 owner). Increasing hp by slapping a turbo on an engine does not require a great deal of sophistication from the engine itself (just solidity from the block etc.) but it does make it more performing. Slapping a (or manny) turbos on an already sophisticated, refined high hp/litre engine (like Porsche does and BMW just did, as well as the Veyron etc.) is the nirvana for performance.

But the turbo lag is still there and those, such as myself, who do not like it will always prefer the GT3 to the 911 turbo.

North American fuel, as least in the US is already "upgraded".
BTW, it's not an "upgrade". It's an issue with sulfur and the US has already had low sulfur fuel for quite a few years. This summer US mandates our gasoline to be 30ppm and less. Thus, we already have the necessary fuel.
The 3.0 twin turbo will not magically get 15% better fuel economy. If the engines computer system is designed to run in "lean mode" MPG could go up. However, it isn't clear if the ECM/ECU has that already.
Thus, as it is the 3.0 TT will not get better MPG, and will probably be worse. And, in actual daily use, as most turbo owners know, MPG will really really suffer if you are an enthusiastic type driver. You can't get something for nothing. Also, the turbo engine doesn't even take advantage of BMW's valvtronic setup. This is an "older" tech engine that is using an old trick to get more power. It's called supercharging/turbocharging.
Yet, it's still a great way to build power.

You need to drive the newer, better, turbo engines such as the Audi 2.0T FSI before you declare that "lag" is such a big issue. Also, you need to understand BMW's 3.0 TT is using very very small turbos which spool very quickly, plus the engine is more designed to have turbo boost to assist rather than provide most of the power. Thus, the torque on the 3 liter displacement with the relatively high compression ratio will give low rpm and part throttle response with nearly no lag.

My E46 325i, and the 330i's, aren't exacty low rpm responsive either.
If you catch 2nd gear in a turn and the vehicle speed drops your engine speed to under 2500 rpm, there is lag in those NA engines as they feel a bit dead until the revs climb back up. Yes, that lag is much less than older turbo tech without direct injection. But, with advances in turbo design and fuel delivery and the use of 2 small turbo's, you should wait until you make dated judements.

[Bimmerista]

Originally Posted by RPM90

North American fuel, as least in the US is already "upgraded".
BTW, it's not an "upgrade". It's an issue with sulfur and the US has already had low sulfur fuel for quite a few years. This summer US mandates our gasoline to be 30ppm and less. Thus, we already have the necessary fuel.
The 3.0 twin turbo will not magically get 15% better fuel economy. If the engines computer system is designed to run in "lean mode" MPG could go up. However, it isn't clear if the ECM/ECU has that already.
Thus, as it is the 3.0 TT will not get better MPG, and will probably be worse. And, in actual daily use, as most turbo owners know, MPG will really really suffer if you are an enthusiastic type driver. You can't get something for nothing. Also, the turbo engine doesn't even take advantage of BMW's valvtronic setup. This is an "older" tech engine that is using an old trick to get more power. It's called supercharging/turbocharging.
Yet, it's still a great way to build power.

You need to drive the newer, better, turbo engines such as the Audi 2.0T FSI before you declare that "lag" is such a big issue. Also, you need to understand BMW's 3.0 TT is using very very small turbos which spool very quickly, plus the engine is more designed to have turbo boost to assist rather than provide most of the power. Thus, the torque on the 3 liter displacement with the relatively high compression ratio will give low rpm and part throttle response with nearly no lag.

My E46 325i, and the 330i's, aren't exacty low rpm responsive either.
If you catch 2nd gear in a turn and the vehicle speed drops your engine speed to under 2500 rpm, there is lag in those NA engines as they feel a bit dead until the revs climb back up. Yes, that lag is much less than older turbo tech without direct injection. But, with advances in turbo design and fuel delivery and the use of 2 small turbo's, you should wait until you make dated judements.

The fuel in the US has sulphur content as far I know which does not permit the Di engines to do a lean burn like in Europe. I agree that the fuel efficiency increase comes from the DI, but only of permitted by the quality of the fuel to do a lean burn.

I have not driven the new 2.0 litre turbo in the A4 but it is not a new engine, simply a reworking of the 1.8t which I had the pleasure of driving for 4 years before in an A4. In that engine I did not like the lag under 2500 rpm. The engine was very good, its just my personal thing.

I am not making any judgments about the 335, on the contrary, everyone and their grandmother here seems inclined to state that the 335 is revolutionary and eliminated turbo lag. Until we have more info and test results, I reserve my judgement. I hope that in fact the lag has been reduced to a level where it becomes irrelevant (especially since we a talking about a 6 cyl with 3.0 litre displacement to beginn with not a smaller 4), since I certainly like everything else about the new twin-turbo engine.

[whippersnapper]

Originally Posted by RPM90

My E46 325i, and the 330i's, aren't exacty low rpm responsive either.
If you catch 2nd gear in a turn and the vehicle speed drops your engine speed to under 2500 rpm, there is lag in those NA engines as they feel a bit dead until the revs climb back up. Yes, that lag is much less than older turbo tech without direct injection. But, with advances in turbo design and fuel delivery and the use of 2 small turbo's, you should wait until you make dated judements.

NA engines by definition don't have lag, what are you talking about?

[ALPINE6SPD]

Originally Posted by whippersnapper

Am I on my own or is anyone else disappointed about a turbo engine?

I don't care what the prelim reviews say, turbos have turbo lag. The response and feel of a high tech naturally aspirated engine is the essence of a BMW. Anyone can bolt on a turbo.

I would have preferred a 300bhp 3.5 liter version of the N52

yep your the only one. Also the twin turbo would get better gas mileage than a 3.5. Plus a 3.5 is heavier so having a 3.5 makes no sense at all.

[whippersnapper]

No-one has made a single cogent argument yet why a 3.5 engine would be heavier. It would need the same component strength more or less as the turbo engine except it would be minus 2 turbos and an intercooler

[gohawks23]

Originally Posted by Tony

Where did you get this from? You mean to tell me that the porsche 911 Turbo engine doesn't have a good feel? And what about the Bugatti Veyron? 0-60 in 2.5 seconds and is the fastest production car ever (power everywhere in the rev range). Which NA engines do you feel have a better "feel and response" than the cars just mentioned?

I'd rather have a light weight turbo engine than some large, heavy, gas guzzling V8 (or 6 cylinder).

People who don't like turbos don't understand turbos...but once they do they like them!

Compared to NA of the same HP/torque turbos are lower weight and offer better fuel economy...turbos are more complex but that is what warranties are for...

[n25nnnn]

http://www.e90post.com/forums/showthread.php?t=14884
i dont think you are going to lag with turbo this size...

u think FI lag.. try small turbo.. or SC

turbo is definately better MPG driving long distance

[RPM90]

Originally Posted by Bimmerista

The fuel in the US has sulphur content as far I know which does not permit the Di engines to do a lean burn like in Europe. I agree that the fuel efficiency increase comes from the DI, but only of permitted by the quality of the fuel to do a lean burn.

I have not driven the new 2.0 litre turbo in the A4 but it is not a new engine, simply a reworking of the 1.8t which I had the pleasure of driving for 4 years before in an A4. In that engine I did not like the lag under 2500 rpm. The engine was very good, its just my personal thing.

I am not making any judgments about the 335, on the contrary, everyone and their grandmother here seems inclined to state that the 335 is revolutionary and eliminated turbo lag. Until we have more info and test results, I reserve my judgement. I hope that in fact the lag has been reduced to a level where it becomes irrelevant (especially since we a talking about a 6 cyl with 3.0 litre displacement to beginn with not a smaller 4), since I certainly like everything elso about the new twin-turbo engine.

Yes, correct, it is the sulfur issue. As I said though that has been addressed and US fuel by law will be 30ppm everywhere in the US by this summer. Much of the fuel in the US for the past 3 years has been dropping in sulfur content from highs of 300-500ppm down to 30-80ppm and even lower by some fuel makers.
Point is, US fuel is capable of "lean burn", so I don't understand why the new E92 turbo isn't taking advantage of it. Also, BMW is probaby just using the lack of knowledge of low sulfur US fuel to compensate for why they haven't worked out their DI NA engines yet.
The Audi 2.0T FSI doesn't run in "lean burn" mode in the US, but that's because it was released before the full US mandate this summer.
Also, the "lean burn" is all about cat-converters and lower emissions.
Lean burn allows a faster and hotter light off to, which doesn't work well if the fuel used has a high sulfur content.
I don't call that bad "quality" fuel so much as a different formulation and possibly a "cleaner fuel. US fuel is high grade and just as good as any good/high quality fuel in the rest of the world.

The new 2.0T FSI is years beyond the 1.8T and is not simply a "reworking" of the 1.8T. The 2.0T is a new engine, but, it would just be a sematic arguement to go any further.
Point is the 2.0T has quite amazing throttle reponse and a very flat and broad power delivery that is far from the peakier nature of earlier turbo designs.

Yes, we do have to wait and reserve judgement on the BMW 3.0TT
I'll bet it will rock. :rocks:

[RPM90]

Originally Posted by whippersnapper

NA engines by definition don't have lag, what are you talking about?

Well, this too would be a semantic argument.
What is "lag"? If it's a lack of throttle response where the power comes after the driver has applied the throttle, then that fits a large number of cars that are NA, supercharged, or turbo'ed.
Is it a lack of low rpm power? If so, then that is negative that can be associated with a number of smaller displacement high revving engines, namely from Honda and Toyota.

"Lag" seems to be something applied to turbo engines to describe the nature of how their power is produced. The general implication is that turbo's have low or little torque at low rpm and then, once exhaust pressure builds up, the power comes on VERY strongly.
The lack of low rpm has become the "lag" issue, which seems to be a greater negative than the BIG hit of power produced once underway.
Also, due to the nature turbo engines, more care is required by the driver to keep the turbo's spooled up and ready to give boost so that throttle control becomes a trickier proposition.
So, all of those things are associated with turbo "lag".

In that light, I made my comment in the general way in which we drivers like our engines to produce power. We want torque at low rpms, mid rpms, high rpms, and everywhere in between.
Well, very few engines can provide that especially with past traditional engine building/tuning techniques. The world has changed and we can now have low rpm torqe and high rpm torque. BMW uses VANOS to create such power spread. Why did they need to do that? Because even BMW NA engines were not known for good low rpm power delivery.
They too can be said to suffer from low rpm power deficits that feel very much like "lag". The same can be said of Honda high revving 4 cylinder engines and Toyota's as well. What is called "lag" in a turbo engine that produces little low rpm power is the same as a "lack" of low rpm power in a NA engine.

Point is, what we are describing is the same thing in NA or turbo or supercharged engines. The difference is degree of the power defecit.
That' why I say that even NA engines can suffer from "lag".

[RPM90]

Originally Posted by n25nnnn

http://www.e90post.com/forums/showthread.php?t=14884
i dont think you are going to lag with turbo this size...

u think FI lag.. try small turbo.. or SC

turbo is definately better MPG driving long distance

Man, that turbo tubing is SO close to the exhaust and cat-cons.
There needs to be some serious head shielding going on if anyone wants to do boost mods. Plus, I've said it before, those little turbo's can't be pushed very much with overspinning them.

A first mod I can see is heatwrapping the turbo tubing going to the IC.

Still, for me 300hp/300lb ft. is PLENTY in a sweet BMW RWD setup.
All that power and performance and a full warranty to boot!
Sweet.

[stressdoc]

You need to be careful insulating any parts of the turbo set up because it can affect cooling in other parts. I would not wrap, but instead use reflector shields. I suspect a proper warm-up and cool-down are going to be helpful for long-term reliability.

[RPM90]

Originally Posted by stressdoc

You need to be careful insulating any parts of the turbo set up because it can affect cooling in other parts. I would not wrap, but instead use reflector shields. I suspect a proper warm-up and cool-down are going to be helpful for long-term reliability.

I hope they include the shields in the design.
Also, I would rather wrap the headers as that can help move the exhaust gases out faster, hm...wonder if that would help spool even quicker?
Also, the wrap would be after the turbo and before the IC, where pretty much all the cooling/condensing is done. The cooler the air before the IC the quicker and easier it should cool. Turbo's are amazing when the temps outside drop. Sometimes if feels like you just got a boost increase for free.


I doubt there needs to be a warm up or cool down. Modern turbo design uses liquid and oil cooling. A simple drive it normal a minute or two before the destination will work just fine. Even the new 2.0T FSI doens't require any special cool down or warm up than a NA engine.
I've owned 3 turbo cars and I love/d them all.

[whippersnapper]

Originally Posted by RPM90

Well, this too would be a semantic argument.
What is "lag"? If it's a lack of throttle response where the power comes after the driver has applied the throttle, then that fits a large number of cars that are NA, supercharged, or turbo'ed.
Is it a lack of low rpm power? If so, then that is negative that can be associated with a number of smaller displacement high revving engines, namely from Honda and Toyota.

"Lag" seems to be something applied to turbo engines to describe the nature of how their power is produced. The general implication is that turbo's have low or little torque at low rpm and then, once exhaust pressure builds up, the power comes on VERY strongly.
The lack of low rpm has become the "lag" issue, which seems to be a greater negative than the BIG hit of power produced once underway.
Also, due to the nature turbo engines, more care is required by the driver to keep the turbo's spooled up and ready to give boost so that throttle control becomes a trickier proposition.
So, all of those things are associated with turbo "lag".

In that light, I made my comment in the general way in which we drivers like our engines to produce power. We want torque at low rpms, mid rpms, high rpms, and everywhere in between.
Well, very few engines can provide that especially with past traditional engine building/tuning techniques. The world has changed and we can now have low rpm torqe and high rpm torque. BMW uses VANOS to create such power spread. Why did they need to do that? Because even BMW NA engines were not known for good low rpm power delivery.
They too can be said to suffer from low rpm power deficits that feel very much like "lag". The same can be said of Honda high revving 4 cylinder engines and Toyota's as well. What is called "lag" in a turbo engine that produces little low rpm power is the same as a "lack" of low rpm power in a NA engine.

Point is, what we are describing is the same thing in NA or turbo or supercharged engines. The difference is degree of the power defecit.
That' why I say that even NA engines can suffer from "lag".

Turbo lag has a definition, you don't need to try and make one up. You know what they say, "if you don't know, then i can't tell you"

[Tony]

Originally Posted by RPM90

Well, this too would be a semantic argument.
What is "lag"? If it's a lack of throttle response where the power comes after the driver has applied the throttle, then that fits a large number of cars that are NA, supercharged, or turbo'ed.
Is it a lack of low rpm power? If so, then that is negative that can be associated with a number of smaller displacement high revving engines, namely from Honda and Toyota.

"Lag" seems to be something applied to turbo engines to describe the nature of how their power is produced. The general implication is that turbo's have low or little torque at low rpm and then, once exhaust pressure builds up, the power comes on VERY strongly.
The lack of low rpm has become the "lag" issue, which seems to be a greater negative than the BIG hit of power produced once underway.
Also, due to the nature turbo engines, more care is required by the driver to keep the turbo's spooled up and ready to give boost so that throttle control becomes a trickier proposition.
So, all of those things are associated with turbo "lag".

In that light, I made my comment in the general way in which we drivers like our engines to produce power. We want torque at low rpms, mid rpms, high rpms, and everywhere in between.
Well, very few engines can provide that especially with past traditional engine building/tuning techniques. The world has changed and we can now have low rpm torqe and high rpm torque. BMW uses VANOS to create such power spread. Why did they need to do that? Because even BMW NA engines were not known for good low rpm power delivery.
They too can be said to suffer from low rpm power deficits that feel very much like "lag". The same can be said of Honda high revving 4 cylinder engines and Toyota's as well. What is called "lag" in a turbo engine that produces little low rpm power is the same as a "lack" of low rpm power in a NA engine.

Point is, what we are describing is the same thing in NA or turbo or supercharged engines. The difference is degree of the power defecit.
That' why I say that even NA engines can suffer from "lag".

Great Post. Folks here fail to realize that all cars suffer from the lack of low-end power (which is what turbo lag is). N/A Cars with little torque suffer the worse. Accelerate an RX8 or an S2000 from 30mph in fifth gear. Check the 30-50, 50-70 (top gear) acceleration times and you’ll find that low-torque cars (S2000, RX8) have worse numbers than any Turbo charged car today when it comes to top-gear acceleration from low speeds. It may not be “Turbo-Lag” but the end results are far worse.

I think folks here use the term “turbo-lag” to try to discredit a great engine without realizing that N/A cars can be just as bad (If not worse) at low revs. The “Turbo-Lag” Argument is weak because all engines (except large 4.0 liters or above) suffer from some sort of lack of low-end power. The smaller the engine the worse it is.

Not liking turbos is okay, but to prefer a 3.5 liter N/A engine over a 3.0 liter turbo from a performance standpoint borders on ignorance.

[whippersnapper]

Tony, what are you on?

1) What is this great engine that almost no-one in the world has driven yet. What a mindless BMW sycophant you are!

2) Turbo lag is present to a larger or lesser extent in all turbocharged engines. No NA engine has turbo lag (duh)

3) Turbo lag is felt as a lack of responsiveness to a throttle action whereby the engine does not provide the full torque usually available at the current engine speed because there is a delay before the turbo(s) spools up and provides it. Why is this so hard for you to understand?

4) Even very sophisticated LPT engines like the FSI Audi 2.0 engine still suffer from lag

5) Turbo lag is about a lack of feel and responsiveness of the engine to throttle inputs and not its numerical performance. This is something that true enthusiast are very iterested in and one of the items that distinguishes great engines

[Joe Bimmer]

Originally Posted by whippersnapper

Tony, what are you on?

1) What is this great engine that almost no-one in the world has driven yet. What a mindless BMW sycophant you are!

2) Turbo lag is present to a larger or lesser extent in all turbocharged engines. No NA engine has turbo lag (duh)

3) Turbo lag is felt as a lack of responsiveness to a throttle action whereby the engine does not provide the full torque usually available at the current engine speed because there is a delay before the turbo(s) spools up and provides it. Why is this so hard for you to understand?

4) Even very sophisticated LPT engines like the FSI Audi 2.0 engine still suffer from lag

5) Turbo lag is about a lack of feel and responsiveness of the engine to throttle inputs and not its numerical performance. This is something that true enthusiast are very iterested in and one of the items that distinguishes great engines

I take it you haven't seen the dyno chart with the torque curve from this engine? It's flat as a board, starting from 1300 RPM's up to 5100 RPM's of even pulling power. If you want to call the gap from 890 RPM idle to 1300 RPM with full torque "lag"...then so be it.

[whippersnapper]

Joe,

Try reading my post again. Take the words in, try and make out what they mean. Then start thinking........can you measure turbo lag on a dyno chart? ...and.... isn't a dyno run under load with the turbos spooled up?

[Joe Bimmer]

Originally Posted by whippersnapper

Joe,

Try reading my post again. Take the words in, try and make out what they mean. Then start thinking........can you measure turbo lag on a dyno chart? ...and.... isn't a dyno run under load with the turbos spooled up?

So where do you think this turbo lag is going to be, at everywhere in the RPM range? My previous car was a 2002 1.8T Jetta with a GIAC 1.1-bar Chip, and at virtually any RPM, if I hit the gas, the turbo was ready to spool. It had amazing throttle response, and hardly a turbo lag. I'm expecting this BMW engine with twin turbos of such a small size to really have no lag at all. I would be very surprised.

Time will tell though. Bring on the test drives.

Does anyone know the specific turbos that are being used? Anyone have specifics on the lbs of boost?

[whippersnapper]

from Edmonds

"Turbo lag, the period of time between throttle application and the turbo's ability to provide meaningful boost, is essentially nonexistent for all practical purposes. Only in higher gears when modulating the throttle to adjust the handling balance can the engine's artificially aspirated nature be detected. Other than that, this new turbo engine simply feels like a larger-displacement, normally aspirated engine."

So this thing that you don't even understand does exist on the new car. Trust me, the criticism will increase over time, especially once the car get involved in comparos which tend to amplify differences

[stressdoc]

More to the point from Edmunds (I find this semantics of turbo lag discussion obtuse):

"Equally surprising is that there is no audible indication of turbocharging, either — the characteristic intake whoosh and turbo whine are completely absent, and there's no bypass valve chuffle, either. The only clue that there's something else going on other than normal aspiration is a slightly bassier exhaust note."

Nice job, little bro'!

[Tony]

Originally Posted by stressdoc

More to the point from Edmunds (I find this semantics of turbo lag discussion obtuse):

"Equally surprising is that there is no audible indication of turbocharging, either — the characteristic intake whoosh and turbo whine are completely absent, and there's no bypass valve chuffle, either. The only clue that there's something else going on other than normal aspiration is a slightly bassier exhaust note."

Nice job, little bro'!

+ 1. For some reason the turbos haters will not acknowledge this or choose to ignore a true driving impression. People should realize that there is more than one way to skin a cat. I can't believe that folks are trying to discredit the Turbo engine's response and flexibility. I guess that they are smarter than BMW’s engineers.

[Insider]

Originally Posted by Yellowcreek

Any word if this new engine will create a shrill cabin noise. Some vehicle turbos I have found are rather noisy.

According to this article http://www.edmunds.com/insideline/do...cleId=116129#2 there is no turbo noise at all.