Originally Posted by
GLHNSLHT2
I put a 52mm on my custom plenum 2 piece 2.5 in the driveway once vs the ported 58mm I was running. The car seemed to rev up just a hair quicker with the 58 of course but not too noticeable. I didn't get a chance to play with it on the street vs the 58 as I had to wait to seal off the AIS passage on it then winter came and I bought another car and off things went on a tangent.
I guess if you make the manifold for a 58mm TB you can always run a 52 if you like it better vs the other way around.