My 2 cents,

I have to say after reading this thread, my SRT6 only has the Eurocharge tune and IC pump upgrade after the original failed. I noticed a difference right after the tune. Smoother power through the rpms and it seem noticeably more powerful. I do not like the K&N air filters because they do allow larger particles in the engine. There are studies demonstrating this and i would rather sacrifice longevity for power any day. I live in Arizona so we have more dust particles in the air here than most places. The smaller supercharger pulley should be a great upgrade from what my many hours of reading, but the intake on these cares are pretty restrictive so that is why many do the CAI upgrade. If i can find a K&N filter style with smaller diameter pores, i would consider this upgrade, and I could just change it the the low restriction filter on track days. Now if only i could get traction...

I have a NA Limited Roaster as well, and have the EC tune, larger throttle body and MAF housing. What a difference between stock and now! I did my tune in increments. I first got the Eurocharge tune. Power was noticeably smoother and i could feel a little more power. After i did my 74mm throttle body upgrade, i saw the car truly come to life. More instant power, a lot more mid-range torque Also, there is no longer a delay in gas pedal that plagued the NA. Sounds a little better too.

I am now wondering if the larger throttle body for the NA made such a difference, would it help the SRT6 without the CAI? Any one do the mod on here?