[Diy_efi] RE: Diy_efi Digest, Vol 1, Issue 506

[Mike]

I was just commenting from the comparative perspective, sorry
I skipped that explanation,

ie. On my ECU by Bosch/Hitachi, the injectors are batch fired
twice per engine cycle ie. Once per crank rotation, on only
one of those injections the inlet valve is open (more or less),
to go from that to a sequential (once per engine cycle) needs
the same amount of fuel and therefore the original injectors
only flow half as much as required.

>From all I've read, for general run of the mill production engines,
the difference between batch fire and sequential is marginal, this
may not be the case with performance machines tuned for either
greater output or for maximum economy etc

rgds

mike



At 10:05 PM 1/11/03 -0800, you wrote:
>I thought the concept was rather like a diesel.  Relatively high pressure,
>fuel introduced as near the time of ignition as possible to reduce the
>opportunity to detonate.  I would expect that time to be long after the
>intake valve has closed.  Am I not understanding something about GDI?
>
>Lance
>
>-----Original Message-----
From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org] On
>Behalf Of Mike
>Sent: Saturday, January 11, 2003 9:50 PM
>To: List for general do-it-yourself EFI talk
>Subject: Re: [Diy_efi] RE: Diy_efi Digest, Vol 1, Issue 506
>
>
>surely you'd need much bigger injectors as your spray time per engine cycle
>is less, or will you raise pressure or also spray a little when the inlet
>valve is closed ?
>
>rgds
>
>mike
>
>
>
>At 05:35 PM 1/11/03 EST, you wrote:
>>well im no EE but ive been working on a AVR based injector controller 
>>that
>>takes a ecm pulse and converts it into a sqeautnaily timmed pulse. im a
>long 
>>way away form having it built. but it can be done. and alot of CDI engine 
>>desiels and the mitsu stuff are in fact rail controlled fuel pressue. but
>its 
>>more in the head return. the point of CDI isnt to spray fuel directly 
>>into
>>the cylinder. its to take advantage of the vaporazation from the heat of
>the 
>>chamber/and being able to time the fuel to stave off detonation with hgih 
>>compresion ratios. a hot injector pintle will really help to atomize the 
>>fuel. this will inturn make it easier to ignite of very lean mixtures. yet 
>>again any GM ecm could be use with a bit of hardware development. then
>again 
>>for all the trouble it might actually be easier to just scratch build 
>>something or use a design similar to the efi332 project. 
>>
>>  its all subjective. there alot of way to skin the cat.
>>
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