Difference between Holley Terminator LS and Terminator X LS?

[Paraman1]

I am trying to figure out what the difference between the Holley EFI Terminator X part number 550-903 and the Holley Terminator LS MPFI kit part number 550-608 are?

[ryeguy2006a]

One uses the Terminator X ECU and the other uses the HP EFI ECU. Given the choice, my vote would be the Terminator X ECU and upgrade to the X Max version to give you more options like DBW and Trans control. But a lot depends on your goals. There are some slight differences with the ECU's, but the biggest one I think is the HP can control low impedance injectors which are much cheaper. Terminator X can only control high impedance injectors which are quite a bit more expensive. @andrewb70 could provide more details.

[protour_chevelle]

550-608 uses the Holley HP ECU Can support high and low impedance injectors, Bosch or NTK WBO2 sensors, dual WBO2 (Dominator only). Outputs can be positive or ground side triggers, internal datalogging, ability to do a System Log. (Stolen from a post of Andrews)

550-903 uses the newer plastic terminator ECU. Some limitations are high impedance injectors only, single Bosch 4.9 wideband O2 sensor, outputs are only ground side triggers, no internal datalogging, no ability to do a System Log.

Chances are the 608 uses a harness that is built in the USA, The terminator harness is typically made in China and comes with bad crimps, wires swapped, etc. Not all but definitely known for the lack of QC.

Both can't do transmission control.

[andrewb70]

https://www.holley.com/products/fuel...uel_injection/

The link above has it laid out pretty well. Scroll down a bit and you will see the differences between all of the ECUs.

Andrew

[Paraman1]

https://www.holley.com/products/fuel...uel_injection/

The link above has it laid out pretty well. Scroll down a bit and you will see the differences between all of the ECUs.

Andrew

Thanks!