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Re: New Member, LT1 Questions/50-55 ponders



Little off this topic but I can attest to being able to come up with some 55
pound P/H units in my 4.9L V6.
My idle runs around 850 with the DFI able to run closed loop/stoich stroked,
no problems.
They can take some pretty high fuel pressures (80 psi no problem) and not
create excess heat in the windings or injector drivers while maintaining
excellent repeatability.  All the other injectors tried in this size range
had to idle 800 rpms more just to get a decent idle (same engine, intake,
big cam, chosen fuel pump arrangement).  The fuel system setup I run is; 50
psi fuel at idle and 75 at anything over 12 psi.  Fuel system is dual staged
Walbro GSS 242 that can do 44 lbs hr at 70 psi and 13.5 VDC per pump, easy
to be able to support 650 hp running 24 psi (out of a 70 lb/min turbo).
Using these in a 8 cylinder would be a good test, and would support a great
deal of hp, running a slightly higher cylinder displacement ratio of .7125
verse .8166.

Jeff M


> What 50's do you recommend for a basically stock motor with S/C that are
> going to have a decent 600-800 rpm idle?.  Would you happen to have a flow
> chart for them?.
>   You say big injectors, and no FMU, but rather a well tuned MAF, OK
what's
> a well tuned MAF?.  you mean use a larger capacity one?.
>   As I recall he mentoned 6 PSI of boost.  For that I don't understand all
> the complication, of what you suggest vs a GOOD FMU, and possibly MAF.
> Grumpy
>   Just asking for further details here.
>
>
>
> > 50# injectors sounds like a lot of fuel to ma also. With a conservative
> > 80% duty cycle and ~.50 brake specific, 640HP can be calculated. If this
is
> > your first project of this caliber, be careful. An FMU probably wouldn't
be
> > necessary, but a well tuned MAF sensor would be paramount. A wide band
O2
> > meter and visual knock sensor device would be mandatory in WOT tuning.
> > Best case scenario would be an engine dyno, tire spin won't allow good
engine
> > loading except at high MPH.
> > Good Luck AL




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