M20 inlet manifold Throttle position

[jimmyspeed]

Evening all, just a quick question about throttle body position.

Will a 320i inlet manifold hold a 325i throttle body in the exactly the same position as a 325i inlet manifold fitted with a 325i throttle body?

any help much appreciated !

[Brianmoooore]

It will bolt on in the same place, but the port in the flange on the 320 inlet manifold is smaller, and if left like this the turbulence caused by the step will reduce power. If you grind out the 320 manifold to match the bore of the 325 TB, there will be very little metal left in places, causing potential gasket problems.
Question: If a 320 is improved by fitting a TB with the bore of a 325 one, why didn't BMW fit a TB of this size at the factory?

[jimmyspeed]

cheers brian , it thought you might know

i understand and agree on the modifying off a 320 inlet, i don't intend to run the engine with the 320i inlet and 325i TB i'm just mocking up some intercooling pipework for my turbo build.

For the final build it will be on a full 325i setup but it would be so much easier if i can leave the 320 inlet in it for now and still be able to move the car about(with minimal work). I just don't want to make the pipework and it be a poor fit.