3000 rpm bog

[R&D man]

I have been driving my m50 swapped e30 for about two months and find that I have a substantial power drop or bog. If the car is in second gear around 3000 rpm and when I step on it ,the car bogs makes a lot of throttle noise but the power is just not there but yet I can still take it up to 4500 or more .
any ideas?
thanks

[JGood]

What RPM range does it feel down on power from?

When my vanos went bad, it made a ton of intake/throttle noise, and went nowhere, from 1k til about 4.5k. Sounds just like what you're describing.

[George77]

Looks like you dont have enough fuel.Check the fuel pressure,if its ok try another air mass.