xr_virgin said:1. It now sounds like it has hair on its ba**s and it matches the aggressive look
2. Power increase yes, fuel savings can be had as long as you dont plough the right foot too much ( but believe me its hard )
3. Full system - extractors, high flow cat and low restriction straight through muffler, 2.5" pipe
Cat back is just the 2.5" pipe and low restriction muffler ( ie whatever is "back" from the catalytic convertor )
Cost ( in sydney ) are:
full system in stainless steel - $2000 ( I think )
full system in mild steel - $1200
cat back in stainless - $1400 ( again I think )
cat back in mild steel - $600
The sound is intoxicating....and be sure to get a cold air intake and filter ( BMC or k&n ) of some sort ( ss induction CAI is pricy but good ).
xr_virgin said:Cold air intake feeds "cooler" air to the engine. Simple fix is to add an XR6T snorkel ( which about twice as big as the standard snorkel ) which is $30 or so.
Expensive option is the SS Induction unit which is about 3 to 4 times bigger again ( fits over the top of the entire radiator ). But it is $400.
Custom CAI's are usually a duct running from the front bumper to the airbox but due to them being so low they are susecptible to filling with water and a lot more fiddling around.
Id recommend the SS Induction, then the XR6T but go with what your budget is happy with!
The science behind CAI is:
cooler air = denser air
denser air = more oxygen
more oxygen = the ability to add more fuel to the mixture without running lean
more fuel being burnt = more power!
The bmc or k&n is just less restrictive and re-usable cloth filter ( meaning you can clean it ) so it will allow more air to flow through it to the engine rather than the throw away standard paper filters.