Headers and Tuning, 2 Questions

[Junkyard Dog]

(1) How much horsepower are headers and a tune picking up on an otherwise unmodified engine? Has anybody seen the results of this yet? The headers should pick up some, and the tune should pick up some, but how much in the real world?

(2) If you live in an area with emissions, not California, can you run catless headers now and (A) pass emissions and (B) run well, just as well as the ecu ran everything with the stock manifolds and catalytic converters?

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[Q6543]

Headers were worth roughly 30-40hp on my car, stock tune.
Not dyno’d, MPH gains at the track.

 

[Junkyard Dog]

Headers were worth roughly 30-40hp on my car, stock tune.
Not dyno’d, MPH gains at the track.

Yep. I have seen you post that before, with the gain at the track.

I keep hearing that there is more to be gained once you make modifications, like headers, by tuning for those modifications.

Another 20? Maybe?

Also, I live in an emissions testing area, so . . . this is something I have to keep in mind.

 

[smurfslayer]

The only dyno numbers I’ve seen posted on a stock Mustang, not tuned was 12 rwhp, not 30-40.
The .25 mile time improvement is impressive though.

It’s the volume that kills it for me.

 

[Junkyard Dog]

The only dyno numbers I’ve seen posted on a stock Mustang, not tuned was 12 rwhp, not 30-40.
The .25 mile time improvement is impressive though.

It’s the volume that kills it for me.

 

[Junkyard Dog]

Different result . . . seems sketchy . . . no before and after, or did I miss it?

 

[smurfslayer]

is that the same guy from keep it dirty off road?
he’s not measuring wheel hp, he’s measuring hub hp; less rotational mass for sure.

 

[Junkyard Dog]

Posted back in October of 2024:

Even if tuning WAS available, you’ll deal with the light.
It’s illegal for a tuner to adjust the post catalyst sensors.

 

[Junkyard Dog]

Posted in December of 2024:

I picked up 4MPH and over 3tenths…

thats a lot closer to 40RWHP not on a dyno, but average track runs.

It was my 3rd mod after springs and spacers… no better bang for your buck.
Not sure why they only gained 12whp on the dyno but track MPH don’t lie.

 

[Q6543]

Both are still true… unsure of the re quotes?

 

[robvas]

I would be very, very surprised if a tune + headers made 60hp over stock

(40 from headers + 20 from tune)

 

[Riptide]

Also, I live in an emissions testing area, so . . . this is something I have to keep in mind.

Gotta get you a "guy" man. I've had catless x pipes on both my 08' and 14' and live in an area with emissions testing. Costs a lil more each year but super worth imo

 

[Junkyard Dog]

Both are still true… unsure of the re quotes?

Just finding what information I can on headers and found your two posts. So I put them here in this thread to add information.

 

[Junkyard Dog]

Anybody have any updates here to what headers and a tune will add to a GT or a Dark Horse?

 

[Junkyard Dog]

Nobody here installed headers and a tune?

It is Whipple or nothing?

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