so i just ordered my BBK full with optional porting and will be tuning the car with the parts listed. arc intake box arc fmic titek v2 o2 housing(ported) stock exhaust mani(ported) 750 injectors fuel pump arp headstuds ets licp test pipe trust Ti catback. but my question to you guys is what size down pipe should i go with? i ordered a 2.75" but have been waiting since november to recieve it and my plans have changed since. i thought about going with the 3" since i will be adding more parts and upgrading my turbo but do you guys think that the 3" is better in my case then going with the 2.75" need advice soon guys as my install date is coming up soon. TIA

 

I don't know how much physical evidence there is between the two but 3" is pretty standardized in evo land

 

I have virtually all the same mods as you an run a Tanabe 2.75in. I switched to a 3in thinking I would gain power and didn't gain squat but worse fitment and clearances issues. My datalogs actually showed I lost off boost response also with the 3in. GST has tuned ALOT of FP Greens, Stock Turbo, BBK, Red and they all made awesome power on the 2.75in.