Originally Posted by Drawn05
Dont need a new intake as the factory 125i airbox is fine. Dont need a new exhaust as the 125i only has one set of cats and not 2 like the 128i. Dont need a DISA manifold (already have it from factory). All that is needed is a more aggressive tune.
I agree. On the 125i I don't think there is much more to come from changing intake/exhaust. From our experience BMW exhausts on Euro spec cars are ver well optimised. Certainly no or little gains from changing the rear exhaust. The cats maybe - but expensive part to change and not sure how much of a market there is for this.
I have some seen some good gains from the Simota intake on the 130i but am yet to test this myself.
On our dyno the 130i is still making more power so maybe the cat section of the exhaust is more restrictive on the 125i.