Looking for a tuner Illinois/Iowa, and question
I have a 2003 e46 m3 with a smg trans.. Currently It is bone stock, I however have a full agency header setup (catless), resonated mid pipes, and an agency race exhaust system. I also will be bolting on a K&N intake system. I plan to bolt this all on myself, then drive it to a tuner who is local to me somewhat and have it strapped on and tuned.. I am from Davenport Iowa, so within 2 hours from me is Des Moines, and Chicago area.. One I think its safe to drive with these mods on my car without a tune, I will just most likely get a check engine light right? And 2 is there any tuner around that can do this I can make an appointment with? Or should I just order a shark injector and do it in my driveway? Final note, I see that average gains for what I am going to do to my m3? I see typical oem dynos around 280whp, and mods like mine tuned may put me around 300whp? Is this true or just false claims by tuning companies? I really don't want to go to a dyno for a tune with a false idea im going to gain 50whp when the truth is I wont see it at all… Not trying to set myself up for disappointment guys? Hope ya understand.. any thoughts?