Civic EG

can i port and polish the head, stage 1 valve train minus cam without tuning the ecu? when it comes to flow like skunk2 intake manifold, bigger throttle body, port and polish, when do i have to tune it?

Josiah wrote:can i port and polish the head, stage 1 valve train minus cam without tuning the ecu? when it comes to flow like skunk2 intake manifold, bigger throttle body, port and polish, when do i have to tune it?

Not a requirement, however I would heavily encourage you to do so with your head port and polished. You won't see/feel many benefits of the parts you uprate so it's a bit pointless adding all of them and not remapping your ECU you'll also compensate fuel economy without a retune.

Quite a lot of people go for a tune when they've added a new part like a larger throttle body, intake mani etc. because they all increase throttle response and in most instances includes larger amounts of air traveling into the combustion chamber which means more/less fuel being utilised which means you'll be running the motor lean or rich. so again fuel economy is compromised.

just to make it a little clearer cause i dont think i made it very clear lol
RETUNE WHEN...

-Head has been port and polished
-Throttle body and Intake manifold are added

To save money while your having the head port and polished have the uprated intake mani and throttle body ready to put on straight away, that way you only pay one fee for the re-tune.
If you have any other parts to be added roughly the same time, have them ready for the remap also and then post your dyno print out