just an in general intake manifold question...

[teh_mugen18]

on a domestic EFI car, if you were to port, or bore out the intake manifold runners just slightly on an IHE bolt-on car with stock injectors, would a tune be neccessary?? Im talkin about maybe a good 1cm or 2cm increase in diameter on each runner.

And ~what kind of amount of additional power would be added to it? Just a rough estimate, i dont really want to go into great detail about the particular car.

[Z U L8R]

whenever you modify a car, it's always in your best interest to maximize the modification's output by making adjustments. vaguely and generally speaking it's always good to be tuned to your set up. however the ecu also adapts short and long term fuel trims/timing advancement in small adjustments based on weather/temperature changes. i would think if you could just clear the adaptations it already has and get it to relearn it to your new/improved set up, that would be ideal. but most likely it'll just monitor the fuel trim via your pre-cat oxygen sensor(s) and adjust itself on it's own.

porting the intake manifold might not even result in a power gain if the intake ports on the head are still smaller or not evenly matched anyways. just don't **** up your intake lol,
gl,
Dave =]

[Z U L8R]

if you're serious and you want to get the most out of your modifications, a suggestion could be to take your intake manifold to Twisted Grimes machine shop in Alpharetta, GA (exit 12 400 north) and have Gary flow test your intake manifold before, then either have him port it or you port it, and get it flow tested again, to make sure most importantly that it's evenly distributed to each cylinder (so you're not leaning out one cylinder more than the others), and also to see how much of an improvement in flow it even was.
just my .02
gl man,
Dave =]

[teh_mugen18]

Thanks a lot man