Iv got a e36 320 n I jus upgraded the Inlet manifold to a 2.5 n throttle body is 2.8 It gives more torc n bhp but to really get the full benefit I been told u need to get it chipped u don't need to change Anything tho it is a strait swap only if it's an m50 manifold
Ive got a 1998 E36 323i tourer i've not changed manifolds or throttle body, but have had a remap. I had the remap put on the car at 238,000 miles by B.W.Chiptune in hounslow near heathrow, (best thing i've ever done) its a hell of alot quicker and beats most 2.5's off the line and lots more power through the rev range. Its now done over 240,000 miles and still runs fine.