RomRaider

Hello everybody,

I am planing a manifold swap from M52B25(nonTU) to M54B25.

My car: BMW e30 Touring MY91
My engine: M52B25 nonTU out of an 323ti compact, Stock.

I compared all manifolds at first:
M50B25 = 190hp --> shorter and bigger runner compared to M52B25TU (expensive)
M52B25 = 170hp --> longer and smaller runner compared to M50B25
M52B25TU = 170hp --> kind of the same lenght and shape as M52B25
M45B25 = 190hp --> shorter and bigger runner compard to M52B25 (very cheap), very similar to M50 runner lenght.

I would like to swap my M52B25nonTU to M54B25 Manifold, which should have the same benefits in a Stock M52 as the M50-Manifold-Swap.

My plan is to manipulate the M54 manifold:
- EVAP off
- PCV line delete
- DISA, off at the first step. Maybe there is a opportunity to use the exhaust flap pin to controll that one.
- fuel injectors M52b25nonTU
- Fuel Rail M52B25TU
- Throttle from M52b24nonTU should fit in there.

Does anyone already compared am B25 eingine with M52nonTU, M54 and M50 manifold against the air massflow and load over engine RPM?

Thanks for any adivce and greetings,
Johnny

honestly, save the hassle of swapping manifolds and save up to get some hotter cams...ive been to m50 mani and back to m52. changing to M54 mani like B30 could be worthwhile, however, it is pretty involved (jerry rigginf needed) to swap and havent seen any reports someone doing this on a m52b25 that its worthwhile...