scooby491 wrote:less boost? i was under impression that it came in due to over boost.....
i run an ej20tt in my gen 2 and it cuts at between 7-9 psi..... as far as i can work out from research theyre meant to run 14 psi flat chat
The FCD makes the ECU 'see' less boost than it's actually getting. eg. ECU 'sees' 7psi when you're actually putting 14psi into it.
Becomes a potential problem because the ECU is giving fuel and timing figures for 7psi. Higher boost you need more fuel or less timing (or both).
That's being pretty broad about it.
It might not be a problem if the factory tune has sufficient headroom in fuel and/or conservative timing. But IMO still not a good idea.