[Diy_efi] New BMW 760, fuel pressure, direct inject

[Greg Hermann]

At 1:21 PM 1/8/03, Mike wrote:
>At 03:13 PM 1/8/03 +1100, you wrote:
>>Some info about toyota direct injection
>>
>>http://www.sae.org/automag/globalview_01-00/02.htm
>>
>>About the Crown and 2jz-fse - "pressure between 8 and 13 Mpa (1160 and
>>1890 psi)".
>
>Ah ok, so this is synchronous - no need for coil to control the injector,
>only done by fuel pressure - and of course spring controls in head of
>the injector. Am I misinterpreting this, doesnt seem like doubling the
>pressure (almost) would give enough dynamic range - unless a 'log'
>flow factor was built into the mechanics of the injector nozzle and
>non-return valve - logical I suppose ?
>
>ie. Fuel pressure goes up by 50% results in much more than 50% more
>flow so at max pressure it could achieve 20:1 to 50:1 dynamic range,

NOPE !!

>any mech engineers out there to comment on how feasible and reproducable
>this is in that environment ?

For starts, you have it backwards. Doublng of pressure only will increase
flow by a factor of 1.414 ! (Sq. root of 2).

Greg
>
>rgds
>
>mike



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