[s-cars] Fuel Delivery Questions

[Sean Douglas]

The stock injectors flow 280 cc/min @ 3.0 bar.

Sean


> -----Original Message-----
> From: Brian Powell [mailto:powellb at gmail.com] 
> Sent: Monday, December 20, 2004 8:37 PM
> To: Sean Douglas
> Cc: s-car-list at audifans.com
> Subject: Re: [s-cars] Fuel Delivery Questions
> 
> 
> 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
>