Looking back the very first mod was a full 3 inch exhaust system and I had a before and after dyno power runs on the same day and if my memory is correct
the car gained 15% and 20 % power and torque BUT it may be the other way around.
So that led to the factory computer cutting fuel as the free flowing exhaust allowed the turbo to be more efficient and produce more boost.
That led to the installation of a "fuel cut defender" that stopped the fuel cut.
So the next mod was having the turbo Hi Flowed for even more power.
So be warned that they can be so addictive that it is so easy to get hooked
the car gained 15% and 20 % power and torque BUT it may be the other way around.
So that led to the factory computer cutting fuel as the free flowing exhaust allowed the turbo to be more efficient and produce more boost.
That led to the installation of a "fuel cut defender" that stopped the fuel cut.
So the next mod was having the turbo Hi Flowed for even more power.
So be warned that they can be so addictive that it is so easy to get hooked