I have an 08 4.6 which I installed the Roush Off-Road exhaust and am contemplating my next mod. Has anyone installed a tune with the stock airbox on a 4.6? I am told that the 4.6's don't gain as much as the 5.4's do with a CAI. I will probably get a CAI later, but I really don't have the $$ to buy both a tuner and a CAI now. Any advice? Thanks.

 

The tuner with stock intake helps tremendously. I have the 5.4 but it works the same for both engines. I have never changed my intake and have no plans to do so.

 

Thanks, that is what I was looking for. I know when I put a tune in my Mustang it made a huge difference. I changed my intake at the same time but I assume most of the increase came from the tune. The elimination of the throttle lag and increased shift firmness alone was worth the tune.

 

You may want to consider a decent CAI, like the AF1 3.0.

I added them one at a time on my last truck and I think the AF1 had more positive impact on my performance than the true dual exhaust and Troyer tunes. The exhaust made it sound way better, but seemed to drag down the performance. I even had them add an X-Pipe, so I do not think it was the low end torque issue I have read about. After adding the tunes, it felt like it was back to about the same as when I first added the CAI (with much better shift points). I removed the CAI just before I sold the truck and the sluggish performance returned.

None of these trucks are fast, so I guess the performance aspect is relative. Compared to my Viper, any F150 will always be a dog...

For the truck I have now, I put the AF1 from my previous truck on when I first bought it about a year ago. I just added the true dual exhaust with x-pipe last weekend and it did not drag it down like my previous truck. I went with the 14" Flow-Masters instead of the Magna-Flows this time, so maybe that has something to do with it. I will be adding tunes in the upcoming weeks. I am debating between VMP and PHP, since Troyer is still way out there on their lead times.

FX4-Texas
Formerly KR-Texas (Needed a 4x4)

 

The exhaust is just for sound and the custom tunes from Bill at PHP do all I need. It added 25 to 30 hp but better than that, really fixed the lazy shifts and downshifts. I nearly got killed trying to pass on two lanes and no downshift. I would not get much benefit from a CAI as I seldom go WOT.

I like it when I am running about 65 and need to pass, it will get me to 85 or 90 in a hurry.