Headers please help.

[gray owl]

I really hope to get some advice. Is the HP gain from headers worth while. Seems to be a big job and the headers are expensive .
So is the HP gain significant enough to justify the cost snd performance gains.

 

[Noobz347]

Typical results from enthusiasts & dyno tests show:


Factory manifolds → restrict flow by design
Long-tube headers → best gains (~20–30 hp & 20–30 lb-ft) when combined with a cat-back/exhaust
Shorty headers → moderate gains (~10–15 hp & ~10–15 lb-ft) and easier install/less cost


Important! - Gains vary based on tune, supporting mods, and exhaust…


Without a tune: you’ll see smaller gains — often just a few hp, because the PCM doesn’t adjust timing/fuel for the new airflow.


With a tune: gains are much more significant and reliable.


So if you’re not tuning, headers alone can feel underwhelming. With a tune, they come alive.

 

[ctandc]

Long tubes on a S550 Coyote and no tune is a big no go. You'll lose power until you tune it. - ECU can't adjust.

 

[I Bleed Ford Blue]

Long tubes on a S550 Coyote and no tune is a big no go. You'll lose power until you tune it. - ECU can't adjust.

That's not true. On my old 17 I was 370 whp stock and 385 after the header install, no tune. Then after the ford racing stage 2 power pack and a custom tune I got 425 whp on 93

 

[ctandc]

That's not true. On my old 17 I was 370 whp stock and 385 after the header install, no tune. Then after the ford racing stage 2 power pack and a custom tune I got 425 whp on 93

Long tubes? I've installed long tubes on 4 or 5 S550 Coyotes, none of them saw much difference until tuned and most ran badly at part throttle. And you installed the Power Pack 2 and custom tuned it? Wasn't PP2 a Throttle body, intake and a tune?

Just going by what I experienced.

 

[I Bleed Ford Blue]

Maybe the 17 was a unicorn, IDK. Yes the PP2 was a TB, intake and tune. I was hoping the PP2 install would clear the CEL from the headers but it didn't so I had a local shop custom tune it to clear the CEL. I just had him clear the code so it will pass emissions, the tune was basically the ford performance tune modified for the header install. BTW the proprietary ford racing tune can be modified, but the only tuning device that will work is HP tuners.

 

[ctandc]

Maybe the 17 was a unicorn, IDK. Yes the PP2 was a TB, intake and tune. I was hoping the PP2 install would clear the CEL from the headers but it didn't so I had a local shop custom tune it to clear the CEL. I just had him clear the code so it will pass emissions, the tune was basically the ford performance tune modified for the header install. BTW the proprietary ford racing tune can be modified, but the only tuning device that will work is HP tuners.

I installed the PP package on my '19 GT when I had it. I didn't have headers on the car, no major mods, I just wanted to bump in low end and it did that at least.