this just suddenly came up in my mind, I'm sure someone asked this b4, tried to search on Google , 7 club and nopiston couldn't find the answer. so ...

if u street port a turbo car u should get a tune. yeah I know, running with stock ECU is just a waste (might even blow ur engine?)

but what if you street port your NA and run with stock ECU? any ill effects ? probably not much difference on the S5 NA cuz stock runs pig rich anyway. what about S4? just curious.

 

I know this is not the answer to your question, but the above statement isn't necessarily true. As long as it isn't a massive street port, you can run the stock ECU.

 

I found answers already, thx

sucks that I can't delete this thread.

 

my opinion is that you can street port and run the stock ecu, but the ecu tune isn't really power optimized for the stock ports. so when you street port it might flow more air, but the ecu will hold you back, and in the turbo cars its probably not safe.

so it would be better to do the ecu on the stock port engine, the NA cars pick up a lot of midrange power with an ecu (10-15hp in the 4-6k range) and then a little after the peak (6500+)

 

If you had an RTek persay change anything? Or does that just affect fuel flow, making adjustments for the larger injectors.

 

a Rtek is good for a ported N.a engine if you dont have cash for a standalone. As long as you have an ecu that can tune fuel and timing, it shouldnt destroy the engine unless you fucked the settings over.