I just had my stock (08' F150 5.4 Screw) exhaust system replaced. It's 3 inch from the Y back to a 14" Maggie and 3" out the rear side SI/SO. Sounds awesome! Downside...in an effort to save $ I took it to a local shop and ended up with non mandrel bent pipe. My bad.......

Future mods were going to include a CAI and tuner. Question is, have I pretty much screwed the pooch or will I realize some performance gains with these mods in spite of the restricted exhaust??

 

you arent really gonna see that much of a different. sure mandrel would have better flow. but its probably not gonna be enough for you to notice. i dont have mandrel bent on mine and its just fine

 

You'll be alright. Since you upgraded to 3" pipe it wont restrict hardly at all.

 

You've sure got me feelin' a lot better about what I thought was a real bad decision on my part just to save some bucks.

Now I can press on......!!

 

You'll be just fine.