EFI - Terminology and acronyms

[gabe]

> Paul Blackmore wrote:
> >
> > Hi All,
> >
> > I have asked this type of question before, but can't seem to find the
> > replies that were sent to me. So if anyone is kind enough to send the info
> > again I'd appreciate it very much...
> >
> > I need to clear up some EFI terminology, forgive me if the questions don't
> > make sense... (I'm a software guy, don't know much about EFI)
> >
> > What are the acronyms for different efi types? And what do they stand for
> > and what do they mean?
> > i.e. TBI, PFI
>
> TBI (throttle body injection) has injectors built into the throttle
> body.  It's the most carb-like system, doesn't require fuel rails,
> air/fuel is mixed in the intake manifold, etc.
>
> TPI (tuned port injection) means (in general) that there is one injector
> per cylinder, and it is located near the intake valve, at the "bottom"
> of the intake, rather than at the "top" like TBI.  Requires fuel rails
> to get fuel to each injector.  Also much higher pressure, like 40psi
> compared to 12 psi for TBI.

TPI is actually an acronym for a particular model of GM engine and fuel
injection, with "tuned runners", not really a generic term such as TBI.  You can
see a pic of it here.

http://www.fuelinjection.com/IMAGES/tpisdbw.jpg

There is also a pretty good history of GM high performance V8 injection systems
here as well:

http://www.fuelinjection.com/portinj.html

Hope this clears up things a little
Gabe

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