say around 15-20kw with a striaght throw exhaust from turbo with no cats
Little if any
eight hp
Maybe 10
by itself, not much, not enough to notice, if you go with a performance carb and air filter as well as the exhaust you will see a lot of difference.
3 to 8 maybey 10 but not likely
about 5 - 10 hp
Not a significant difference all the dual exhaust does is cut back pressure ergo the louder sound
Very little. It is better to have duals instead of single as it is harder for the car to breath. But it can add 5-10 horse.
when you steal a trolley add a engine maybe a vtec and some nitrous and even add a steering wheel then race someone in a skyline
cat back? 12hp/12ft-lbs.
10 to 20 percent
Not enough to even notice.