Buy the 2.75 inches ID 90 degree silicone coupler from Bakerprecision. Cut it down to size at one end, slip in the hard pipe; cut the other end down to size, couple the silicone coupler with a large clamp to the y-pipe.

Because the hardpipe is encased by the 90 degree elbow, it doesn't slip off and loses boost. At least that's the theory; mine hasn't pop off after a couple of 13 psi runs. We'll see if this will truly hold.

The best solution would be to somehow configure a new 90 degree hardpipe to be bolted to the the Efini turbo y-pipe
with two screws.

 

Good job ,Garfinkle made a pipe from a 90 and a flange that attached the efini to the KW innercooler ( same as m2 ) . He got the pipe from Burnes stainless . The new set up with BNR big turbos , he cut the flange off the efini pipe and made a new flange with 5 bolts . It is mounted much lower . The 90 degree pipe ( from Burns )with its 5 bolt flange sits lower and clears the shock tower brace better.The new set up looks great and seals better .It is so fun when a plan comes together .

 

im a little confused so you are using the 90 bend from the y pipe to the intercooler core inlet? can you post a picture?