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      06-23-2013, 08:47 AM   #66
NISFAN
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Quote:
Originally Posted by swamp2 View Post
........Yes and we all know turbo lag is the operating range of an engine before the large dynamic increase in power as a turbo system gains rpm and is finally able to build boost pressure, pump effectively and thus increase power.
Layman's term maybe, but wrong to a drive train engineer.

Quote:
Originally Posted by swamp2 View Post
In this operating range such an engine will feel decidedly powerless and unresponsive to throttle inputs. Exactly what EVERYONE knows and calls turbo lag (apparently except you).
No, I unapologetically use the engineering definition. If I were to go by 'EVERYONE's beliefs then I would also have to close mindedly accept that 'Torque wins races' or other nonsensical definitions. Just to recap, a turbo engine responds to throttle input EXACTLY the same as an NA engine, afterall it actually is an internal combustion 4 stroke engine.

Quote:
Originally Posted by swamp2 View Post
We also know that a hypotentical 3 liter M4 with no boost will be lucky to make 300 hp. A lack of power, compared with perhaps 450 peak hp when the turbos are not at appropriately high rpm will be obvious. Now that being said we also know BMW is going to try all sort of trickery (trickery not in a bad way but in a good one) to try to reduce or possibly even eliminate turbo lag. Perhaps using triple turbos or even an electric turbo or both.
If you had used torque in your argument you would have been onto something, but totally failed with the horsepower reference. Lag on a modern turbo system at peak horsepower revs would be negligible. I know you probably used it for a more forum friendly reference, but down the wrong track. The higher the revs = the higher the exhaust gas energy = lower compressor spool time.

At least you agree that, say, the S63Tu at 4.4 litres even when in 'lag' state will be at least if not better than an s65. Kind of poo poo's the people who believe the F10 M5 F12/13 M6 suffers from lag. I'm pretty sure I feel strong acceleration when driving the M6

Quote:
Originally Posted by swamp2 View Post
Bias is not the correct word. I enjoy the S65, independent of whether I own one or not. It is an absolute gem of an engine and the international motoring press have heaped praise on it as well. It also won International Engine of the Year in its class in case you forgot that important detail. Much of the praise for the engine includes is razor sharp throttle response. It is just about as lag free as possible as an engine can get.
Yep, you are definitely biased towards the s65.....comes across really clearly. It is a great engine by the way, and deserves the credit it has received. Sadly it doesn't fit in with the modern way of doing things. You have to move with the times in this industry.

Quote:
Originally Posted by swamp2 View Post
Really, get with the program here. This is not even much of a debate or even discussion with you.
This new engine direction has stumbled on a V8/I6 thing, but probably a bigger factor is the NA / FI thing.

Obviously current M3 owners would like the engine they know and love to move into the next car in some form or another.....but simple facts are, to extract the increase of power required, BMW would have to go against the global trends for economy and emissions, on an already thirsty engine.

On the plus side, there was equally as much debate about the F10 M5 / M6 dropping the s85 engine. Seems like s63tu has gone down well with new owners, with only 'the sound' being a negative.

As for turbo lag, check out race two in this e60 M5 vs. F10 M5 (race two singled out as it was closest start point for the both in terms of reaction time). Not bad for a over 100kg heavier car with 12% less displacement.

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