N*Power Headers

**ekx105** · 12-04-2012 09:10 AM

Hi OzHonda

so im looking into getting a N*Power Headers for my Ek civic. I just want to know will i need to get a cat or anything else to complete the install.
My Eki is CXi and the engine is bone stock (d16y8) apart from a K&N Apollo Cold Air Intake System.
And im also running a Spoon N1 Axle Back.

Will i have any issues with install? or would it be direct bolt on.

any help/answers would be greatly appreciated.

Neil

**dougie_504** · 12-04-2012 10:52 AM

Not necessary, but I recommend getting a hi-flow cat anyway, as well as some larger back-pipe to sit between the hi-flow cat and your Spoon N1.

Otherwise you'll have a restricted section of exhaust between your header and muffler.

Should bolt straight on though.

**ekx105** · 12-04-2012 02:08 PM

Thanks for that.

Which brand of high-flow cat would you go for?

And if i didnt get the high-flow cat amd just bolted it straight on, would that be fine? And get a high-flow cat later down the track?

And as for the back pipe, im pretty sure the Spoon N1 is 2.25 like the header.
Im pretty noob at this stuff, so im always open to new info in regards to these things.

**dougie_504** · 12-04-2012 11:40 PM

You said you have an axle back, which is only the last meter or so of exhaust. You will therefore have standard sized exhaust piping (1.75"?) from the standard cat to the axle-back, which will act as a restrictive bottle-neck. Check and confirm this before you proceed.

For the high-flow cat I recommend a brand like Metal or Magnaflow, those are the only two I have experience with so far but have been very happy. Personally I'd be trying to get a 100CEL rated 2" cat to match your header, unless you want to get 2.25" back-pipe to match your axle-back, in which case I would get a 2.25" cat.

I recommend doing it all at once to save money on labour rather than doing it in two or three goes.

Exhaust goes like this:
Header ---> catalytic converter (cat) ---> back-pipe (cat-back) ---> muffler (axle-back's are usually just a short piece of cat-back with a muffler attached).

So ideally you want a whole system that comprises of all four components. It's best to maintain the diameter consistently throughout the system, or otherwise go from smaller to larger diameters to prevent bottle-necking. For D-series engines I always recommend 2" or 2.25" max. Some people will tell you that 2.5" is fine, whereas others will tell you that going too large will slow down the exhaust gases too much and you will lose power/responsiveness in the low-end of your rev-range, thus making the car a pig to drive. What you want is maximum exhaust gas velocity to get it out ASAP - this is a fine balance between too small/restrictive and too big/spreading out too much instead of moving forwards.

So I were you I'd go N*Power header (2") to a 100CEL high-flow cat (2") to some good back-piping (2") to your Spoon N1 (2.25").
OR
N*Power to 100CEL 2.25", back-pipe 2.25", N1 2.25".

When you get back-piping also consider the steel type and bend type.
Stainless steel is shiny, more durable, and makes a higher-pitched noise generally. Mild steel is dull to the eye, slightly less durable (not poor though) and makes a lower-pitched sound like a rumble.
Press bends are when you simply bend the pipe into shape, which can cause diameter inconsistencies due to 'kinking' of the pipe. Mandrel bends are formed by stretching the pipe instead and therefore produce a consistent diameter through the bends which is considered superior.
If I were getting a custom back-pipe I would choose mild steel for the noise type and mandrel bends for performance/quality.

Hope this helps!

**1996_EK_Civic** · 13-04-2012 12:04 AM

they bolted straight up to my y8, came with all gaskets and bolts, good bang for you dollar

**mugen_ctr** · 13-04-2012 01:02 AM

Im pretty sure N power and OEM have very similar diameter size, 2 inch or so where it bolts upto... so it would be a direct bolt on. But the donut gasket on N power is slighty larger to oem but not that much.

As far as high flow cat, no need... For a engine like ours, d-series, u wont make any power or notice any improvement, i know cause i switched to a high flow cat an only improvement was sound lol

IF u want a quite system, Its all down to the B-pipe Design and muffler used...

Perfect example of a quite exhaust system, Jus because it has a canon DOESNT mean its loud, infact its far from being loud! infact its one of quiet system ive heard and used. Its all down to the B-pipe design. Noticed on 5zigen it uses a Large centre muffler with a small resonator, this means a relative quite exhaust note.

**hitoriko** · 13-04-2012 07:51 AM

What Dougie said - i couldn't ahve said it better myself.

IMO i would go and get a 2.25, if your planning to go turbo within the next 12 months consider getting a 2.5 system to say you cash later.

**CRXDEL501** · 13-04-2012 07:56 AM

Originally Posted by dougie_504

You said you have an axle back, which is only the last meter or so of exhaust. You will therefore have standard sized exhaust piping (1.75"?) from the standard cat to the axle-back, which will act as a restrictive bottle-neck. Check and confirm this before you proceed.

For the high-flow cat I recommend a brand like Metal or Magnaflow, those are the only two I have experience with so far but have been very happy. Personally I'd be trying to get a 100CEL rated 2" cat to match your header, unless you want to get 2.25" back-pipe to match your axle-back, in which case I would get a 2.25" cat.

I recommend doing it all at once to save money on labour rather than doing it in two or three goes.

Exhaust goes like this:
Header ---> catalytic converter (cat) ---> back-pipe (cat-back) ---> muffler (axle-back's are usually just a short piece of cat-back with a muffler attached).

So ideally you want a whole system that comprises of all four components. It's best to maintain the diameter consistently throughout the system, or otherwise go from smaller to larger diameters to prevent bottle-necking. For D-series engines I always recommend 2" or 2.25" max. Some people will tell you that 2.5" is fine, whereas others will tell you that going too large will slow down the exhaust gases too much and you will lose power/responsiveness in the low-end of your rev-range, thus making the car a pig to drive. What you want is maximum exhaust gas velocity to get it out ASAP - this is a fine balance between too small/restrictive and too big/spreading out too much instead of moving forwards.

So I were you I'd go N*Power header (2") to a 100CEL high-flow cat (2") to some good back-piping (2") to your Spoon N1 (2.25").
OR
N*Power to 100CEL 2.25", back-pipe 2.25", N1 2.25".

When you get back-piping also consider the steel type and bend type.
Stainless steel is shiny, more durable, and makes a higher-pitched noise generally. Mild steel is dull to the eye, slightly less durable (not poor though) and makes a lower-pitched sound like a rumble.
Press bends are when you simply bend the pipe into shape, which can cause diameter inconsistencies due to 'kinking' of the pipe. Mandrel bends are formed by stretching the pipe instead and therefore produce a consistent diameter through the bends which is considered superior.
If I were getting a custom back-pipe I would choose mild steel for the noise type and mandrel bends for performance/quality.

Hope this helps!

Great info dougie.

**ekx105** · 13-04-2012 10:04 AM

Thanks dougie for the info on exhaust/exhaust and header systems. Gave me more of an understanding!! Thanks mugen cte too!

Its good to see forum members help out with actual info rather than get flamed for being a noob!

Thanks everyone!