Originally Posted by cross><hair
Full Exhaust and slicks? How restrictive is the stock exhaust on the SRT? I know with the STi and MS3 the single biggest performance mod (other than tuning) is to replace the down-pipe (restrictive cats). It freed up close to 40hp in the STi and about 35-40hp in the Mazda.
The AMG cats are very good. Many have tried to replace them with high flow cats only to find little or no gain... and I'm one of them
I believe there is a lot to be desired in the gearing. A ratio of 3.07:1 is not very good for the track (unless you are making huge power). Another area that can be improved is transmission programming; I feel that the 3-4 gear change comes too late. If we could hit 4th a few hundred RPM sooner, we could take more advantage of the great mid-range torque these engines produce, rather than riding out the flat spot at the top of 3rd gear near the end of the track.