From everything I've been told the 98.5 and 99's are the ones that MIGHT not like the wire being tapped. My pump lasted 20 min. Truck had 85,000 miles

 

I meant to qualify my statement. The pulse width cannot be extended past the limits encoded in the ECM. The EZ stays entirely within the stock ECM limits. It just shifts those limits around.

For example, the stock ECM is programmed to delivery max fueling at a certain RPM, like 2700 rpm. This is the "limit" encoded in the ECM. At RPMs other than this, the ECM has different "limits" encoded.

What the EZ does it make the highest limits available across the RPM range. So instead of only having peak fueling at 2700rpm, you might get it at 1900 rpm.

If you graphed the fueling curve with RPM on the X axis and fueling rate on the Y axis, you would see that the curve is both flattened and shifted left by the EZ.

When you see the specs for the EZ (x amount of fuel at 0psi, 100% at xx boost, etc..) what they're telling you is how how steep the lower left part of the fueling curve is. It also tells you how much fuel you have available with a stomp of the pedal.

On the lowest setting, the EZ will not allow fuel fueling (peak ECM limit) until 20psi of boost is reached. This is "100% fueling" value. When you floor the pedal, you have 33% of this "peak fueling" available without waiting for boost to come up.

ON the most aggressive setting, you have 66% of the "max fueling" available with a simple stomp of the pedal. You *DO* have to wait for boost to come up before getting 100%, but only until 3psi of boost!

On the middle setting, it's 50% on the "stomp factor" and 100% of fuel is available after 10psi of boost.

The stock ECM varies fueling by varying the duty cycle of the bypass solenoid inside the VP44. The stock limit of xx% (I have been told it's like 28%) is the peak fueling that the EZ cannot surpass. That's why MOST of the the power from the EZ comes from timing advance, not so much from fueling because it can't drastically increase fueling.

Now once you tap the wire, the ECM limitations disappear, and your only limited by what your fueling box commands, and how much money you have in your VP replacement fund. For example, a 63% box like the Blue Chip MORE THAN DOUBLES the duty cycle of the bypass solenoid inside the VP. This is where the big fueling (and big power and big EGT) comes from.

Thanks for the catch, Rusty...

Justin

 

HOHN,

Can you make that more complicated??


Just kidding

 

I could try...