Quote:
Originally Posted by NISFAN
So tell us how long a turbo takes without MGU to spool between those ranges? 
And also tell us if that was a disconnected turbo, or under load? |
Are you not getting it, or just playing dumb?
Your first question shows you don't seem to understand how a engine and a turbo works... It's kind of asking how long a length of string is
How long a turbo, without MGU, takes to spool up between rpms depends on (amongst other):
- Throttle position (part throttle, WOT etc)
- Engine rpm
- Turbine A/R
- The engine's operating condition when you want the turbo to spool up (coasting, steady state driving, acceleration)
- Exhaust temperature
- Exhaust volume
- Exhaust speed
Those are some of the reasons we have something called turbo lag... With a MGU you can spool the turbo regardless of the above circumstances.
This chart is from Garrett's webpage:
http://www.turbobygarrett.com/turbob..._ball_bearings
400Hz = 24000rpm
2100hZ = 126000rpm
So, according to Garrett, it takes between 1,6 to 2 seconds to spool up a turbo from 24000rpm to 126000rpm
From 40000rpm (666Hz) to 120000rpm (2000Hz) it takes approximately 1-1,2seconds.
And that is when the throttle is suddenly opened at 2000rpm on the engine. The MGU can operate idependently of engine rpm obviously.
To quote Garrett engineer:
Quote:
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by incorporating a very high speed electrical motor in rotating assembly of a turbocharger, you can drive it up to very high speeds, before you have exhaust gases to do so. It is very powerful, specifically when there is no exhaust gas available, such as at idle, or in stop and go.
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This presentation has some comparisons on
throttle response between a regular turbo and a electrically boosted turbo.
http://www.aeristech.co.uk//userFile...esentation.pdf
The chart on e-Booster acceleration (1) shows that it takes
0,38s to spool from 60000rpm to 100000rpm at 0,51Bar
In June this year Aeristech displayed their first low voltage system (48V).
www.aeristech.co.uk
Engineers at Renault F1, Garrett and others agree that a MGU/eBoost turbo can help eliminate lag, and spool up the turbo quicker than the exhaust gases can do under many circumstances. Exactly which parts of those companies engineering expertise is it that you disagree with? I'm sure Renault F1 and others would love to get some inside knowledge from you
