2.0 to 2.5

[VW-will]

Hi guys, Got myself a 89 2.5 am i right in thinking this is will drop straight in to my 89 2.0 ? as they are both facelifts?? thanks, Will

[Kieran_n22]

should do. you will need a 2.5 air boot, chip for ECU (you can get one from speedtouch) and it's better to get the 2.5 exhaust aswell.

[daimlerman]

Would also suggest that you swap the small case 320i diff for a medium case 325i type,as well!

[Sanchez]

Will the diff change help the B25?

[Green]

It will make it rev lower as it's a bit high revving with the 320i diff in it, also you'll ideally need the b25 prop as well when you change the engine, for either diff.

[VW-will]

if you use the 2ltr gearbox, the prop wont need too be changed, the 2ltr gearbox is just as good, if not better than the 2.5 one imo gears are a bit longer

[hongkongfuey]

the 2ltr box is not as strong as the 2.5 , some have them say they are fine , others have broken them, not really a job you want to do twice, also does this 2.5 come with afm? its better to have 325 ecu instead of 2l one less messing around, the 320 diff will be 4.1 the 325 is normally 3.64

[goosiegander]

very true, 2 litre box ratios are very close to those of the 325 sport's

Not managed to break my box yet with the 2.8 but for the sake of £150 a decent sport box will be a good investment

[Sanchez]

Ive not broken my B20 box with my B25 engine and the diff is a B20 small case one.