question about mods on a ~05 auto coupe

[cicatrizdare]

How much of a power gain is expected from intake plenum spacer, catless exhaust, intake, and y-pipe on an ~04-05 coupe?

I have a friend with these mods on his G35 automatic coupe who I might run and I just want an idea of how quick this thing will be. I've run a 6spd with an intake from a 15 roll and got taken by a car to 90, but from what ive seen the autos are not as fast as the stick.

If kill stories or questions arent allowed please disregard and get rid of this if need be.

Thanks for all help!

I drive a volvo s40 t5 (intake, catback, wastegate rod adjustment) btw.