I have done a 2.5 to 3.0 swap before. I have actually used the existing accessories, and it works great, no codes. However, it is best to go ahead and get the bigger maf, intake, airbox, and computer. Everything else is the same. The manual gearbox is the same from a Z3 2.3i to a 530i, as long as it is a 6 cylinder, it will work. You can even put a 6 speed transmission from a e46 330i ZHP in as long as you can get the driveshaft to work.
Originally Posted by Shires
If it has a manual transmission you'd also need a gearbox, ancillaries (shift linkage, airbox, MAF etc) and driveshaft.
On the other hand a 2.2 engine would drop straight into a 525i and vice versa.
2004 BMW 330ci Silvergray Sport Package, Cold Package, Xenon Headlamps, Premium Package, 6 Speed Manual, Build Date 9/03
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