[Diy_efi] Intro, and q's about fuel economy

[Mos]

On Mon, 16 Dec 2002, Alexei Pavlov wrote:

> pedward at apsoft.com wrote:
> > The only way to eliminate throttle losses is to have no throttle at
> > all.  You then do the throttling via modulation of the valve timing.
>
> Could you explain why there are no pumping losses with variable valve
> timing or clearance ?
> I see variable valves exactly like throttles, the piston still has to
> pump the vacuum to reach the BDC. The energy loss is still here.

Are you guys talking about variable valve timing? or variable valve lift?

You'd need some large amount of timing variance to be able to control
cylinder filling with timing alone.

Continously variable valve lift is probably more than beyond the scope of a uni team.

On a more related note - with no pumping losses a cylinder will fill
completely with its volume at ambient pressure - is there a way, other
than making it harder for the air to enter, to limit the filling mass?
More to the point - is it possible to have cylinder filling control with
*no* pumping losses.
Letting it fill completely then releasing some before compression?

Mos.

-- 
84 AE86, 90 ST185GrpA, 91 MX83Gr, Sydney, Oz.



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