Fuel limits

[68dartguy]

Is it safe to max out the fuel levels in the lower two rpm bands? I have a 04-5.7 hemi in a 68 dart. It ET's pretty good but I think it can do more.

[brandy16]

What do you mean by max out the fuel levels. You can add fuel and even if you add to much you wont hurt the car or truck. It may not run good with too much fuel. You can add fuel and then data log to see if you need more fuel but the best way is to get a wide band to know for sure.

[Mike_Levy]

Why exactly are you adding fuel? Just dumping in fuel does you no good, in fact too much could extinguish the spark. Generally you would only add fuel to quench knock.

[mikel]

Maxing out fuel without a WB is a bad idea...

[68dartguy]

Thanks! I'm asking because:
1. The motor is in a 68 Dart bracket car.
2. It run's 12:95 in Las Vegas, it should run at least 12:50's
3. Ive only added about 10% fuel @ 5-7 RPM band and about 5% in the lower 2 RPM group
4. From your reply's... Dyno is the best tuning tool?

[DGatzby1]

68dartguy. Yes, of course the dyno is the best. But, you can do some tuning yourself. Log with the Predator. Reset your fuel back to zero adjustment and log for ST knock at WOT at few times. If it is not pulling timing, there is no reason to add fuel.

It should run 12.5's? So how was it tuned when you did that? I would start there.

[68dartguy]

Log with the Predator??? Can I do this while making a pass? What about timing? Put more or less with RPM increase?

[ChrisPTGT]

For what you're looking for, I would highly recommend a dyno and a wideband O2 sensor.

You can log(data-log) with the Predator while making a pass. Timing, knock, speed, throttle position, etc.