[s-cars] Fuel Delivery Questions

[Brian Powell]

Sean, thanks. I realize that manifold pressure is the dominant
variable, I am just looking for rough figures for the stock injectors
(exactly like what you have below for the RS2 injectors).

What I am trying to calculate is how much fuel is delivered by a stock
injector when it is opened for a given time (in milli-seconds) as
compared to the RS2 injectors (with a different opening time) under
same boost conditions.


On Mon, 20 Dec 2004 20:16:02 -0800, Sean Douglas <quattro20v at telus.net> wrote:
> Brian:
> 
> The fuel pressure changes depending on the pressure (boost) being
> applied to the FPR. I did some testing of this in the summer by applying
> a known pressure to the FPR and measuring the pressure in the fuel rail
> while running the fuel pump. I was trying to decide if the fuel pump
> created enough pressure to run the injectors at the desired flow rate.
> From what I recall, the measured fuel pressure was between 96-98% of the
> target and there was a noticeable improvement after I relayed the fuel
> pump.
> 
> From what I've read, the flow rate of the RS2 injector is 360 cc/min at
> 3.0 bar and 415 cc/min at 4.0 bar.
> 
> This thread from Scott Justusson may help shed some light on the
> calculations;
> 
> http://forums.audiworld.com/s4s6/msgs/39294.phtml
> 
> Sean
> 
> Sean Douglas
> 1997 Audi S6//RS2-spec
> 1990 Audi 90 quattro 20v
> 
> 
> > -----Original Message-----
> > From: s-car-list-bounces at audifans.com
> > [mailto:s-car-list-bounces at audifans.com] On Behalf Of Brian Powell
> > Sent: Monday, December 20, 2004 12:23 PM
> > To: s-car-list at audifans.com
> > Subject: [s-cars] Fuel Delivery Questions
> >
> >
> > Just trying to do some calculations so that I understand what
> > is happening in our cars. The stock FPR is 4bar, correct?
> > What is the normal pressure that it should keep it at during
> > wide open throttle at 1k rpm increments? Does it try to keep
> > it at a constant 4bar?
> >
> > Also, what is the flow rate of the stock injectors at 3bar and 4bar?
> >
> > Thanks.
> >
> > --
> > Cheers,
> > Brian
> > _______________________________________________
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> >
> 
> 


-- 
Cheers,
Brian