Elite 1500 GC8 Wrx varex back pressure query

[WRXLuke]

Hi all,

Newbie to Haltech here. I recently purchased a 1999 Wrx with Elite 1500 with supporting mods for a safe tune by Chequered Tuning of 200kwatw.. I have just switched from a standard xforce cat back to an xforce varex twin tip.

Do I need a retune? Read on for more detail….

Intention is to keep the car quiet while trundling around and then always open the exhaust before using anything higher than 3,000 rpm.

-When fully open the varex is still a little quieter but power seems close to what it was with the standard xforce.
-When fully closed the car is very quiet but is waaay less powerful above 3000rpm (just tested it the once).

Car is idling and driving fine.

I am happy to never accelerate hard with the exhaust closed, but do I still need a retune to compensate for the new cat back? Unsure if Haltech compensates.

Thanks from a newbie.