It has come to my attention that North American 550 models year bulit post 2000 have precats in the exhaust manifolds which reduce performance quite substantially. This was not a problem for European models, who are not faced with the stricter N.A. emissions guidlines.
I have heard quotes of as high as 0.5 secs difference for 0-60 times between 1997-1999 and 2000-2001.This is an outrageous situation!
My question is...what can be done about it?
Are there after market solutions...ie,new exhaust manifolds.
Can one purchase and install European exhaust manifolds without reprecussions ?
Looking forward to hearing from anyone in the "know"