[5erman]

Hey guys so I understand the concept behind piggy backs but I guess from variosu arguements on here I mis understood what the pbx is actually doing.

This is spurred on by the comment regarding you wont notice a difference if you are in cool weather or at high octane.

I was thinking that the pbx is able to advance the timing above and beyond what the stock ecu is able to do and not just "enable the max ecu's timing advance"--so I see if it were cool and you had high octane and no pbx, the ecu would be maximally advancing timing.

I thought a pbx would multiple this and add additional timing but is this not the case?

[mike-y]

I think the pbx adds fuel more than anything else. honestly, I don't think timing is altered much with the pbx, but the AFRs on my dyno were definitely changed (richer) when the pbx was on.

and like you said, it may only be able to max timing within the computer's allowable range. so with good gas, you'd already be running max timing. Maybe someone with an obd2 reader can track timing changes with and without the pbx.

[ska///235i]

T

[e90pilot]

That's how it alters timing. It adds fuel and the ecu will advance ignition timing automatically. I don't know how the ECU adapts long-term. Some have stated that it will adapt to the box and actually create less power, but I have not seen anything to substantiate that claim.

[5erman]

that is a weak way of adding timing-you can richen the picture with a 2 dollar resistor