the new exhaust helps a bit with the lag, and the car sounds much better now, not to mention the exhaust is a ton easier to work with as it comes in sections, lighter, etc.
this was an obx e46 3 series sedan exhaust. it doesn't quite fit the XI as the very front resonator hits the transfer case mounting. but otherwise the exhaust would fit up.
what i had to do was rework the bends as well as make a merge into a single 2.5".
2014 X1 - m-sport - stock
2004 325xi top mount turbo - megasquirt3 for engine, 5 speed swap. build thread
1994 supra MKIV - single 72mm - bc272 cams - super spec twin plate clutch - aem v2, 1000CC ID, dual denso pump, j&s ultrasafeguard
2004 SE-R SpecV turbo - megasquirt3 j&s ultrasafeguard - SOLD