Custom full exhaust for NA, not a muffler shop job. opinions?

boorishid

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Ok so ive been making alot of posts and doing alot of research lately about engine builds..

Im pretty sure if i decide to go the NA/NOS (direct port of corse) i will have problems smogging. Milling my head will Cause my NOX reading to go up, and down the line building a forged block with hi compression cp's will also cause a huge NOX fail....

I called a close friend with an idea he said he could fab it up for about 100 to 150 bucks. The exhaust would consist of a straight 2.5 pipe from the header back to about the last exhaust hanger. Touldnt even be able to see my tail pipe what so ever as the muffler would be mounted about 3 feet back from the bumper under the car. I think this would look really nice no fart cans sticking out the back and no bends. The idea is to make a complete flanagble sytem where i can bolt two cats in series for smog testing then drive around with one hi flow cat the rest of the time. The idea being if i retard the timing a bit for a smog using my ems or a cam gear, and cut the fuel trims. I could bolt up two cats inline and and this should lower the nox that would come allong with running like a 10:1 or 11:1 compression scheme in are car?

Also mufflers are big and sitting under the car they might get ruined so i was thinking about just taking the pipes and running a resonator all the way from the cats instead of a muffler and praying my car wouldnt be lous as all hell? Or at least a res combo with a small straight through combo...

PS i know a weeek ago i was really thinking FI, but i read up and i dont want an impound, plus all motor sounds like the **** compared to spool and its unique, especially if you forge the block for a direct port nos system you could crank out at least 325whp im assuming. That would be a fast NA i4 6th gen.

This is all theory but all in all does it sound like a way to shave the muffler look and get damn good compression and still pass smog. This would be a completely straight pipe with heat coating and allow me to run any configuration of no cats or two oem cat back to back. Maybe even heat coating or exhaust wrapping the cats would work well to beat smog on hi octane with booster mixed in?

I have decided im determined acually to go all hi compression motor with hi nos shots and beat smogs with cats hopefully, becuase a smog tech has never gotten under my car, and if they did who would ***** im opting to run inline cats....

Motor would be completely stealth to chp all internals and an h23 manifold wich looks pretty stock still unless your a honda expert.
 
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silverbullet99

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two OEM cats back to back? haha I hope you got deep pockets dude, they're 900 bucks a piece. 550 if you or one of your buddies works at a honda dealership.
 

ryan s

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be like it is
I think you have a lot of big dreams.
:lawl:
Logic and rationale eludes you.
eloquent post, fine chap :coffee:


well i'll be honest...i only read about half the post. as far as i see it, you have 3 options:
1. pay someone to pass your car. may or may not be feasible.
2. return it to stock every time you have an emissions test. definitely not feasible if you have to swap engines.
3. move*

*best answer.

believe it or not, there are places in the nation where if you don't have the loudest exhaust or dont race around like a tool, the state and the police could give a ****...
 

Mike's_Taffeta

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^ agree completely. Although I don't think moving is an option.

OP, you really aren't paying attention when we respond to your posts. You're trying make make **** legal with modifying illegally. If you want to pass smog and be fast, only buy parts that are carb legal and do not say "for off road use only"

I think you really need to make a decission: modify your car however you please then pay to pass smog ( I know someone and I live in sb county)

Or keep it legal and pass smog like every other person out there.

Your idea of two cats would be ridiculously suspicious to any smog tech and running a 2.5" exhaust straight pipe would be so obnoxious that I would personally pull you over and slap you lol.
 

boorishid

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well i never said for sure straight pipes. and i had no idea oem cats costs so much thats just a bimmer for so many other reason not including this idea..

As i said though i dont think it would be so suspicous ive never has a smog tech get under my car as long as it passed and under the hood parts have carb stickers. Unfourtantely moving is not an opition, even a cheap cat and a hi flow should do a better job at clearing up the nox readings id think..

I know you guys think im crazy or stupid or not listening or whatever, but idk its not that i just cant move and would like to find the easiest way every two years to pass and not go to impound. prety much all my plans are legal in the state of cali except for ****ing around with the two cats to pass and raising the compression.
 
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