Quote:
Originally Posted by Jim Pearce
I'm no expert, but it isn't clear to me that a forced induction engine can't have a relatively flat powerband of 5,000+ rpm. Of course it would start 1,000rpm lower. Actually I think the M engineers will solve both this and the "linear throttle response" fairly easily.
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I would say keep dreaming. That is all wishful thinking, like mentioned plenty of times before. The 5000+ rpm flat powerband is irrelevant when the car only revs up to 6800 - 7000 rpm. Using tall gearing, it does not need any power above 5000 rpm and given the turbo makes all its peak at 1500 - 1800 rpm, the cross over with HP at 5252 rpm dictates that it will never be making more than 60 - 70% of its peak torque above 5252 rpm since the peak HP does not happen until 6500+ rpm. It is physically impossible unless the torque peak gets shifted up in the rpm band.
The linear throttle response is another wishful thinking. Porsche has not been able to remove that because it is a nature of how turbo works and they are currently the leader in terms of getting better throttle response using variable turbine geometry. Even by changing the angle of attack of the turbine blades, it still requires reasonably more time to spool up than say a completely N/A high-revving GT3, which is instantaneous. Still the best throttle response in Porsches are in the GT3 and the older Carrera GT. None of the turbo Porsches come even close.
Yet, in the SUV market, they have been more successful than BMW since the throttle response, although laggy, in the Porsche Cayenne Turbo S is still WAY better than the X5 M because the Turbo S uses Variable turbine geometry while the BMW does not.