safc ground question

[marc3]

when plugging up the safc, iknow one of the grounds goes before the other, and that they must be 1cm apart.
i also have an apexi 'smart' turbo timer, which has a ground that goes on the same wire as the safc, to decide the cooling time and give me an afr reading.
my question would be , where do i plug my timer ground, before or after the safc grounds?

 

[Bondango]

Ground as far back from the SAFC wires as possible or Alternatively use the ECU's second Power ground. 7M's have 2 grounds 1 directly above the other i.e. 1st 2 pins.