Multec1 vs Multec2 injectors.

[burn]

multecII have a faster opening rate (sensitive springs, responsive coil) than sluggish Multec Is. The Multec Is seem to have a stiffer spring and heavy internal body. THe MII take advantage of the SFI while the MI have to be a bit stiff because they all fire at the same time regarless of what engine cycle the cylinder is at. That valve will have a nice puddle behind it.

It takes more FET power to run the MultecsI at idle than the Multecs II.

22lbs Multec IIs seem to run excessivly rich on a stock 3.1ECM even if the ECM had 22lbs Multec I programmed. I think Ben had problems tunning them. I know some 3400 swap guys did and said they woun't work well on the MPFI ECMs.

My indector Duty cycle with 35lb GTP Multec IIs are about .29 at 700rpm to get it within 13.5-14:1 a/F ratio. After that...I had to mod the VE tables like Multec Is. Idle is a pain with thise multec IIs.

If you have them flowed at a shop..im sure you can get more flow out of the MII at light bpw than the same rate M1 . At 100% DC they are the same. Even at 20-90%. But under that...the MII deliver more.

Fantastic information, I greatly appreciate your response. This is pretty-much exactly what I have been suspecting.

[TurboGTU]

Some will argue that the PW from the ECM or controller at the shop will deliver the same amount of fuel...Not so.

Just like ignition coils..each injector has its own charicteristics.

Say for example a FET is sending a .9 mirosecond pulse..each injector will open at a different rate and response time. THe Badass ones (multec II and newer) will fire almost as soon as the coil is powerd and fire for those .9 miroseconds. The sluggish ones will prob not open or will open for alteast .4 seconds of those .9 FET emiter seconds.