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Setting injector size in TunerStudio

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Old 07-29-2010, 09:31 PM
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Default Setting injector size in TunerStudio

I am running 460cc RX7 injectors, what should my injector settings look like in TunerStudio?

Right now my Required Fuel is set at 5.8 based on:

Engine Displacement: 1600cc
Number of Cylinders: 4
Injector Flow: 460cc/min
Air-Fuel Ratio: 14.7

Does that sound about right?

I've got a bunch of stumbling issues and I'm trying to eliminate one variable at a time. (Mods: Please don't get upset if I end up with a bunch of threads, I want to examine each one separately)

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Old 07-30-2010, 12:01 PM
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Seems to be in the general neighborhood.

One thing to bear in mind is that getting Req_Fuel just right isn't actually all that important. You could put 10 in there, and if you then halved the values of your VE table, your actual injection duration would be the same.

As an example, I personally use a ReqFuel value of 3.5, even though I have the same injectors as you. This isn't even remotely close to the "correct" value, however it happens to be exactly 100x the MS1E-HR's native injector pulsewidth resolution (35µs) so each step of 1 in my VE table increments the calculation by exactly one step, and I don't waste VE resolution on values that will never be achieved.
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Old 07-30-2010, 01:11 PM
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Originally Posted by Joe Perez
Seems to be in the general neighborhood.

One thing to bear in mind is that getting Req_Fuel just right isn't actually all that important. You could put 10 in there, and if you then halved the values of your VE table, your actual injection duration would be the same.

As an example, I personally use a ReqFuel value of 3.5, even though I have the same injectors as you. This isn't even remotely close to the "correct" value, however it happens to be exactly 100x the MS1E-HR's native injector pulsewidth resolution (35µs) so each step of 1 in my VE table increments the calculation by exactly one step, and I don't waste VE resolution on values that will never be achieved.
Makes sense.

My issue now is that regardless of how much I've Auto Tuned (several times through the whole rpm band at different loads) my AFR is still pretty ragged. It's getting better progressively so I'm not worried about it too much.

However during steady acceleration while cruising the car cuts out and stumbles/bucks pretty bad. The AFR will jump from between 9.5-22.3 and you can feel lags where there is no fuel. I'm trying to eliminate each variable and try to figure out why it's doing this.
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