Hi guys has any one replaced there stock 2 inch Exhaust on an X.R.6 F.G to a 2.5 inch system and if so did improve the low down torque or make the performance go backwards.

havn't done it but it could only improve performance along with fuel economy.

You will see a benifet from it for sure, if it's a turbo it will require a flash tune though.

Gab

i changed my g6e exhaust. went from the single 2 inch to a dual 2.5, with hi flow cat and extractors. works well, seems to have alot more go once you get it moving. still just as sluggish to get it off the line as it was originally, unless you have the revs up in the first place. im thinking thats more first gears fault than anything. fuel economy is good, i drive in the suburbs mainly, so abit of stop start, but its not uncommon for me to pull around 600+ km from a tank. as a side note, if you change the exhaust on a bf2 onwards (bf2/fg1/fg2) you will need a tune to cancel out the check engine light. since bf2 there is now 2 o2 sensors, and changing the exhaust sizing results in different readings to these sensors making them think your fuel mix is too lean orrich and changes accordingly. a tune will tell the car to ignore the 2nd o2 sensor.

when i had my f xr6 i went to a 2.5 single muffler system but also kept the standard exhaust tip on it, i noticed that me acceleration was a hell of alot more responsive, torque was a little better but more noticeable in the wet (very hard to take off without spinning) and my fuel ecomeny was better by .3ltrs per 100km around town and hiway runs was .5ltr per 100km better. mine was a manual though, it went even better when i changed over to a cold air intake.