Hot cam injection volume changes

[tom cloud]

>>I just got my '70 302 Ford running with the Holley Projection 4DI ECU.  This
>>is a batch fire MAP system.  The cam is a high lift (.550"), medium duration
>>(224 at 0.050"), hydralic roller from Crane.  The system indicates that at
>>least a -50% correction is required at idle, 700RPM, to get the mixture
>>correct if the stock 302 look up table is used.  The injection volume table
>>is based on RPM and MAP signal.  
>
>How do you like it? Is it what they play it up to be?  Which one did you get
>(45/65/85 lb/hr?)

        [ snip ]

Thought you'd like to see a note one of the (well known) regulars on the list
sent me re the 4di (won't mention his name 'less he wants to say who he
is).

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Oh no! Not a Holley! I hope you don't have the 4Di. That system is
terrible. The one with the knobs on it is much better. I recently worked
on a 93 Liconln Town car with a big block 605 in it. Carbs didn't work
too well so they put on the digital Holley system (4Di). Damn thing
would barely run.
Holley just didn't put enough control into the thing (like how much RPM
you can add in hi-cam mode). They try to use a standard O2 sensor for
wide range control. Put a scope on it and it was WAY off. I will
eventually put an EEC on it to get it to run right. Car is real strange.
Canary yellow, BIG wheels/tires and probably 600 HP. When I'm driving it
around people just laugh....until I push the throttle a little bit!!!

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[ the "one with the knobs" is the Pro-Jection.  There's a 2 bbl (670 cfm) 
and a 4 bbl (900 cfm I think).]

Tom Cloud <cloud at peaches.ph.utexas>