I have the 3000 pipe,and have just replaced my upper ic pipe with 2.75",from the spearco outlet,which is 2.5,i put a 90 deg piece of pipe on,pointing upwards,then used the straight silicon converter,to go up to 2.75", it comes up through the hole where the old airbox used to be,and up to the ssqv,i had a flange welded on the 2.75" pipe,that then goes into the hks 3000 pipe,i noticed in an earlier post that the bigger the pipe the more the lag,why is that,i thought i was doing myself a favour,in making it equal size to the hks 3000 pipe,from as near to the intercooler as i could.id also had a blitz nur spec fitted,which was a bigger diameter than the 2.5 exhaust i had before,i was making 338 bhp and 394lb torque,but i was expecting more now,with these latest mods,would that not be true ? i have noticed however,that off boost drivability and acceleration,did improve,BUT,since refitting my AEM,which came back after a recent repair,off boost driving is slower than with the stock ecu !!