Originally Posted by
jontysafe
I would would be looking at your tune and exhaust port sizes. You're going to find little difference by changing to the 7064. There in reality will be circa 300rpm +/- difference in spool on a yb between the two.
What you have said is completely wrong and not from a experienced point of view. The 7064 monsters the 7163 in every area past 3000rpm there is no comparison between the two from there.
The only area the 7163 is very slightly better is at 2000rpm to 2.5k due to the exhaust flow restrictions that kill that turbo as soon as you want big boost. Overlay the comp map on both and it's as plain as day to see.
Mark