Big Injectors in Little Engine?

[Chris P.]

It dependes on the % of change, but those variations are normally
negligible. One-off low-budget boosted motors typically use larger injectors
with a lower starting fuel pressure and a rising-rate pressure regulator set
a little rich to lower combustion chamber temps to reduce the chance of
detonation. I don't know how tolerant GM injectors are since GM tends to
"design inexpensive" but Bosch, etc, can handle 80+psi. It looks like there
are two topics on this thread so I can't be specific but my $.01 is I
wouldn't base injector timing on size changes but on CFM's after cam,
header, etc, flow characteristics. You'll need AFM and probably a Dyno to
tune it, unless the group has other gadgets I don't know of yet.

If you are going to get into your current injectors anyways, you should take
an hour and just test them.

Oh, and us race car drivers like cold gas because it makes the intake air
colder thus denser...

I appologize if I'm outside the groups general personality, I'm just trying
to share what I know so I can hopefully get some help with my non-programmer
background problems... you know, that back scratching thing...

Chris P, newbie.

>
> Slippery slope on lowering fuel pressures.
> Just remember, as you reduce the pressure, the fuel exiting the injector,
> has less inertia, so it doesn't get as close to being sprayed on the back
of
> the intake valve.  That results in poorer vaporization.   There was some
> stuff about raising the FP made for better atomization, I think it's about
> getting more fuel hotter.  Course, this is just how I seez it
> Bruce
>

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