what works on 360's tubi, cat flow thru, does chipping or air filter work make a difference
Dyno graphs people post on here for tubi/filter/straight thru systems mods have shown (IIRC) small increases of about 1 or 2% (5-10bhp or whatever) across the complete rev range. To be honest your never going to feel that difference, its just going to sound different. In terms of chipping, you must have options, chips producing different effects, like overfuelling, increased revving, but these may not effect peak values, rather just change the characteristics of the engine. You may be able to rev the engine higher, but does that give you more peak usable power? You might get some nice flames on overrun ... umm hehe, Ive never seen a flaming 360 - plenty of flaming 348 and 355s though!!
It depends on how much you want to spend. Changing the exhaust or air filter will not give a significant power increase. At best you are looking at an increase of a few bhp. The weight reduction of a sport exhaust and the sound improvement may trick you to feel a difference in performance. De-cat pipes will improve the sound but may upset the chip setting so consult an expert beforehand. Sport exhaust + chipping will give a fair increase in power output. I think it is more effective to start with tyres, wheels, suspensions and brakes before moving onto the engine, unless you just want to go fast on a straight.