Has any one used this miller cai

Mdarosa54 · Post by **Mdarosa54** » Thu Jul 24, 2014 8:22 pm

Hey I have a 1987 325e 2.7 will this cold air intake I know this works with the 325i but I'm not Sure if it will work on mine http://store.vacmotorsports.com/miller- ... p2503.aspx

Post by **Yoshi** » Fri Jul 25, 2014 1:27 am

I helped install one once. Wasn't too bad but I didn't notice a difference in power.

Post by **M20_fever** » Tue Aug 05, 2014 2:51 am

I'd bet money the stock setup flows better than that one.

Post by **Yoshi** » Tue Aug 05, 2014 11:23 am

technically, the maf gets rid of the "trap door". But I think the main bottleneck is the head ports more than the intake track.

blasphemy101 · Post by **blasphemy101** » Tue Aug 05, 2014 6:14 pm

Ideally, removing the "trap door" in the AFM from the intake track frees up horsepower. From the way it is shaped internally, it looks like it could cause some issues with flow, due to some abrupt transitions in the shape/area of the intake track. It also takes work (energy) from the flowing air to move the door. (I'm sure you know what I mean, I'm just trying to explain it a different way).

That said - I'm not sure you'd even be able to measure the change in power on a dyno, let alone feel it while driving the car. The AFM door is very light, and the whole thing is designed for this exact purpose - measuring airflow in a way that is unobtrusive to the rest of the intake system. As long as there isn't anything providing resistance against the door's movement, it shouldn't amount to a huge restriction for a stock-ish engine.

Like Yoshi said, the AFM is not the bottle neck in the M20s intake system, and any minor restriction before the intake ports/valves likely won't make a huge difference. The M20 heads flow fairly well for what they are, but the engine still isn't exactly starved for air.

blasphemy101 · Post by **blasphemy101** » Tue Aug 05, 2014 6:15 pm

I guess I should be more clear in saying this kit may very well make real horsepower gains, but most or all of the measurable gains are a result of changing the engine management system and a more aggressive tune.