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dfi for dummies?

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Old Dec 13, 2003 | 11:48 PM
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dfi for dummies?

HI this are my modifications that i have done to my 89 camaro: 383 stroker 350 bored .030 over. 3.750 stroke and 5.7 rods, srp dished pistons 9.8 compresion ratio forged internals, dart pro1 aluminum heads, 215cc intake runners 2.05 intake valves 64cc, crower solid roller cam duration 288/290 lift .570/.584 lobe separation 112, crower highrev kit, 1.5 roller rockers, TPIS miniram intake manifold with accel 32lb injectors and coil, fuel press at 55lbs, stock distributor small cap style, 58mm bbk throttle body, accel DFI gen 7 Ecu with calmap... 3.73 gears hooker super comps long tubes headers with mufflex Ypipe and 4inch exhaust..

i just started trying to tune the computer, i couldn' t the car runs good at idle, but after 1500 rpm and up starts to run super lean, what table should i work with??
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Old Dec 14, 2003 | 11:48 AM
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From: Chasing Electrons
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Re: dfi for dummies?

Originally posted by Revel
I just started trying to tune the computer, i couldn' t the car runs good at idle, but after 1500 rpm and up starts to run super lean, what table should i work with??
There should be a fuel table that is either PW or VE based. Like a 2 dimensional array that has RPM as one axis and load (MAP) as the other.

RBob.
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Old Dec 14, 2003 | 04:34 PM
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You need to start with 2 tables... Target Air to Fuel Ratio, and Base Volumetric Efficiency. Pick a nice safe A:F ratio at a given MAP/RPM point, then raise or lower the Volumetric Efficency number at that same point until your actual A:F ratio matches your targeted value. Raise your VE value to richen things up, and lower it to lean things out.
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Old Dec 14, 2003 | 05:21 PM
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with the trace mode on?? the value at the monitor panel?? at the lower part of the screen?
thanks a lot guys, im just started tuning a learning my way around calmap...

Jim
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Old Dec 15, 2003 | 06:28 AM
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When you're online to your ECM, there will be a light blue frame centered around the cell that the ECM is pulling fueling values from on your tables. It will move as your engine operating point changes.

You can either make changes on the fly by altering the framed cell's value, or you can use the trace mode function to "record" your path through a table as you tip in the throttle. Whichever is easiest for you.

A third option is to do some datalogging, then overlay the resulting data over a table. This is like the trace mode, but you can see more data and step through it point-by-point.

If you haven't already, I'd recommend using the VE predictor utility (Fuel->Utilities->VE Estimator). You put in your engine/camshaft/mods data, and it will create a safe fuel table that you can start to tune on. It will be much closer than the one that came preprogrammed in the ECM.

Check section 1.4.7 of your manual, it lays out everything you should look at to get your engine started and running.
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Old Dec 16, 2003 | 11:17 PM
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.....and buy a wideband 02 sensor so you know where you are.
just my $.02
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