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BerDz3nA
04-14-2018, 06:28 AM
Anyone installed just the headers on a stock zhp ?
I am interested in changes, what were the obvious changes you've seen ?

Low/High RPMs ? Sound ? Acceleration ? Torque ?
Has anyone dynoed before and after headers ?

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Reasoned1
04-14-2018, 03:12 PM
I would LOVE to change headers but am, thus far, dissuaded due to emmissions and connection questions. I think Magnaflow offers some sort of alternate cat design for the E46, but I haven't had all my concerns addressed.

Newjack
04-14-2018, 04:58 PM
@Hornung418

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Sockethead
04-14-2018, 06:33 PM
RPMs don't change but headers add torque everywhere. Sound won't be that much louder with the stock exhaust but all the aftermarket exhausts will be seriously louder.

If you want the most bang for your buck, skip everything else and just do headers and a gear change

Hornung418
04-14-2018, 06:38 PM
All of the things. Headers are huge plus for responsiveness and sound. If you have the time, effort, and ability to do it the right way, it's worth it.

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ZHPizza
04-14-2018, 07:14 PM
Has anyone done headers with high flow cats? Losing the cats is the only thing holding me back from trying headers.

Reasoned1
04-14-2018, 07:16 PM
And what is the right way? Is there a solution that provides satisfactory emissions performance without coding out faults and having to re-engineer all the wiring connections?

Hornung418
04-14-2018, 07:28 PM
And what is the right way? Is there a solution that provides satisfactory emissions performance without coding out faults and having to re-engineer all the wiring connections?Right way as in get it coded for emissions and using new gaskets, studs, and nuts. You're bound to have leaks if you don't. Pay for the quality ones or you will have fitment issues like me and have to pay a shop to chop and reweld the flanges.

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Reasoned1
04-15-2018, 02:27 AM
Does "getting coded for emissions" mean cover up the fact emissions are not working--kind of like how VW engineers do it?

Hornung418
04-15-2018, 04:19 AM
Does "getting coded for emissions" mean cover up the fact emissions are not working--kind of like how VW engineers do it?Hahahaha!

You can have someone tune/code the car so it disables the post catalytic monitoring and shows the readiness signal as N/A, thus avoiding any check engine lights and emissions failures.

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Sockethead
04-15-2018, 06:01 AM
I had the secondary O2 sensors and SAP completely coded out like they were never there...

slater
04-15-2018, 06:48 PM
schmiedmann makes some nice headers, with optional 'section 1' (M3-speak) piping with high flow cats. looks like a decent option, but i'm not sure the cats will get hot enough to do anything.

idrivemyself
07-26-2018, 05:01 PM
I have the ebay headers with DEI Titanium wrap on my ZHP. They make a nice difference across the power band and sound great on the car with the stock ZHP cat-back. The CEL is the only downside...


https://www.youtube.com/watch?v=w_y-nm2KXjk&feature=youtu.be

YoitsTmac
07-26-2018, 11:15 PM
^^ that's stock muffler?? I'm doing this soon and...damn maybe I won't also do a muffler.

Newjack
07-27-2018, 04:35 AM
Hahahaha!

You can have someone tune/code the car so it disables the post catalytic monitoring and shows the readiness signal as N/A, thus avoiding any check engine lights and emissions failures.

Sent from my Pixel XL using TapatalkThis is the way to do it. Code out the CEL and you're good to go until you have to pass emissions.

If you need to pass emissions like I do, Google area 74 o2 simulator. It's effectively saved the N55 crowd from the government nonsense. Works on any vehicle.

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idrivemyself
07-27-2018, 11:36 AM
^^ that's stock muffler?? I'm doing this soon and...damn maybe I won't also do a muffler.

Yep, and that's through a camera phone! You can see the stock ZHP exhaust tips in the video. The sounds are even better under load at full tilt... :drool

YoitsTmac
07-27-2018, 05:43 PM
Yep, and that's through a camera phone! You can see the stock ZHP exhaust tips in the video. The sounds are even better under load at full tilt... :drool

I saw that but I honestly couldn't believe it. That sounds fricken fantastic! Congrats! I'm installing mine this weekend but am also going to put in a magna flow muffler. Now I'm worried it'll be too loud!

idrivemyself
07-28-2018, 07:26 AM
Thank you! I've long debated replacing the stock primary resonator with an x-pipe, but with the sound as-is...

Good luck with yours, post a video after it's done!

YoitsTmac
08-01-2018, 11:54 PM
Header install delayed. Basically pulled every muscle in my body doing misc work on my car and a friends. Headers install next time I have energy! I'll make sure to post a clip.

Bob1035
05-23-2022, 08:01 AM
This is the way to do it. Code out the CEL and you're good to go until you have to pass emissions.

If you need to pass emissions like I do, Google area 74 o2 simulator. It's effectively saved the N55 crowd from the government nonsense. Works on any vehicle.

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necro thread....

might have a set of headers available, but I'm confused about the above. If I code out the post cat sensors (Kassel EU2 tune), would the simulators still be needed?

ZHPizza
05-23-2022, 02:29 PM
necro thread....

might have a set of headers available, but I'm confused about the above. If I code out the post cat sensors (Kassel EU2 tune), would the simulators still be needed?Kassel can code out the secondary O2's so you don't have a check engine light. You won't pass emissions though as they'll show "not ready."

If you need them to show readiness/cats are working, then you'll either need the area 74 simulators or an actual catalytic converter installed somewhere before the sensors.

Bob1035
06-03-2022, 07:42 AM
Thanks for the info!