Originally posted by HoHun
Hi Isegrim,
If the supercharger wheel was cropped, an entirely new power curve would result, but from the speed curve you can see that it smoothly approaches the normal speed curve above full throttle height so it's definitely not that.
But you've pointed out an important aspect: Maybe the (very) slight reduction in altitude power we're seeing is the result of a lower compression ratio implemented by using shorter piston tops?
This would allow the use of slightly higher boost pressures at low altitude at a slight reduction of high altitude power. At least the latter is evident from the graph, the former is hidden by the much larger increase gained from MW50 use.
Regards,
Henning (HoHun)
Hi HoHun!
First I must clarify what I wanted to mean. I belive they have reduced the 2ns SC speed gear ratio to a lower level, which meant the supercharger was running on a lower RPM compared to the previous configuration. This is what is called "cropped SC" in English, right? Maybe I used wrong term.
This would result in lower power drain from the engine towards the SC. At low altitudes where less supercharging is needed to keep constant boost, this increases power in a way by conserving more power to the engine.
At higher altitudes this reduced supercharging capacity isn`t enough to keep up power.
I am fairly sure that they did something to the supercharger.. Otherwise why would they refer to a the "A"-Supercharger [configured] as a low altitude supercharger? (If my translation is correct.
In any case it`s clear from the curve that there is only ONE supercharger speed. The Bodenlader-speed curve has no stops or breaks, it`s a straight line, unlike the others, indicating contstant power (up to 3500m).
I think it`s is likely to be that they probably disabled the 1st supercharger speed (which saved some power drain already), and changed the 2nd SC gear to a lower RPM (less power drain again).
So the additional speed is due to the power saved at lower altitudes with reduced supercharging. That seems a simple enough explanation, without too much complication. But it`s maybe possible that additional or other ways were used... it`s hard to say for sure w/o having some hard evidence, we can only speculate.
As for your idea, would it be technically possible to increase powers with B-4 fuel, with reducing the CR, without premature detionation?
