Originally Posted by tom2112
Another note about ECU tunes:
Their value depends on how heavily you mod your engine!
If you're just adding a Code3 or 178mm pulley and a cold air intake, an ECU tune is not worth the money.
But once you start greatly modifying the amount of air your engine can draw, you'll get beyond what the stock programming can adjust for, and potentially blow your motor.
So draw a line after the cold air intake and Code3 or 178mm pulley. If you don't go any further, don't bother with the tune. If you add intake manifolds, polished Y-pipe, etc. etc. etc. Then definitely get the tune. If you go larger on the pulley: get the tune. You get the idea.
tom i think thats some inaccurate info your giving here. running any pulley with a setup like a dual cai really leans a engine out. the tune is critical to ensure detonation and lean conditions are addresed. you may not feel it while driving but it doesnt takemany lean runs to cook a motor. my 32 was running bad lean with homemade intake mods and a c3 pulley. my intake wasnt flowing anywere near robs dual cai flows and i was running lean. the tune fixed it.
the line should be drawn at stock. anything after that should req. datalogging and adjustments based on the engine logs.