Double (high flow) catted frontpipe?
 

Hey everyone,

I was wondering something concerning the front pipe and emissions.
I have read up on some catted frontpipes, but it seems that people, who get 200 CEL high flow catted frontpipes for their 86, and have no cats other than that one, seem to fail emissions or only pass it when the cat is really really hot.

So before i continue, this is my current setup:
1) Tomei UEL exhaust manifold (NO cat)
2) Japspeed overpipe
3) Milltek Frontpipe (NO cat + resonated)
4) Custom made catback (resonated)

What is was wondering, in order for my car to pass emissions, would it be possible and would it affect performance much to get a (probably custom made) double high flow catted frontpipe? This way the car has 2 catalytic converters and emissions wise everything should be all good i suppose. Could anyone pitch in if they maybe have or know of any double catted frontpipes or if they know how they would affect performance. I guess the car would also be way more quiet right?

Greetz
Joe

Instead of wasting money just swap your stock exhaust manifold back on, pass emissions, swap parts. Enjoy.

Well, that could indeed easily be done, problem is, if a cop pulls me over again and smells the exhaust fumes, or tells me it's too loud or whatever, he can make me follow him to a technical control and they'll inspect the car... at that point i'll be screwed...
SO instead of investing in a catted header, and the fact that i love my tomei uel header, would this double catted front pipe be an option or... would it be too restrictive or useless?

Don't understand me wrong, your idea makes the most sense, but i live in a loud-car-unfriendly zone/country which loves emissions testing... so yeah :/

I understand. I'm not able to answer the double high flow cat question, also I don't know your countries emissions. Is it illegal to modify any emissions component? If so that might be a problem if the cop asks you to pop the hood. I swaoped my stock muffler back on after installing my uel and the car sounds stock. That might be an option for you to deter cops from thinking your car is modified. Anyways sorry I wasn't able to answer your question but good luck sir.

yeah exactly, it's illegal to remove or replace any component concerning emissions, in my case the catalytic converters.
My cars catback exhaust is custom made specifically to be legal, so technically they can't say anything about the car being loud, but they will pull me over for it, but once they smell it, and they will, that's where i have a problem.
Therefore i was thinking of a double catted front pipe :)
And no problem, i'm just debating and figuring out if it's worth it, might be that in the end i just keep driving catless and once i have to pass emissions i put everything back to stock lol!

Thank you for the input though!

Each country has it's own rules and it's own checking ways. Imho you'd be better consulting with some local friends/forums and official published local rules on modifying to see if there is some loophole and how to deal with it best. I'm not sure that generic answers based on lot of guesswork in international forum will do much good.
P.S.
Imho single stock cat of higher cell count will be as effective as two high flow ones of lesser cell count in cleaning up exhaust.

True, i'll post it on the local forums too, but since our GT86/BRZ car scene is way smaller, i thought i'd post here to see if anyone has done a double catted frontpipe :)

What you say about 1 stock-like cat is interesting though, maybe if i use just the stock front pipe it could pass emissions indeed

You might be able to pass emission test with the Perrin catted front pipe. However it is no longer in production.

Do you know what kind of catalytic converter they use? :) I might just cut my current front pipe and weld a cat in there lol

Honesty if it's not stock you will most likely fail, don't really care where you are. Just make it easier on yourself, keep your stock parts, and put them on in the worst case scenario and deal with the consequences just like everyone else when and IF you get pulled over by a cop. Also if you ever do get pulled over just shut the car off as soon as it happens. If you don't want to deal with that it might not have been the best idea to "fix up" your car.

Well, that's how i'm going right now haha. I don't really mind it either, i'm just thinking in the long run, i'm clear for another 2 years before i have to start emissions on a yearly routine (it only starts once your car is 4 years old).
I'm only interested in the catted versions since it's easier and less work to switch it out instead of also doing the exhaust manifold.
But what you say is completely true :)

JoeHK: most probably single stock cat in front pipe will cleanup exhaust gases enough on warmed up engine. Primary one in header/closer to cylinders (which is one that hurts performance most on our cars) is mostly intended/placed there, as it heats up sooner to working temps and lets passing exhaust check of later standards versions, that check exhaust also from cold starts. In such sense two less restrictive cats of total somewhat similar restriction as single secondary stock one won't result in something like what stock cat system does for cold starts. Just thrown out money to get alternative but similar to stock front pipe.

Very stupid of me but very true, i didn't think of it that way...
So my best bet would be just to every time i have to go to technical controls, switch out the front pipe and drive the car warm (very warm) and it should, theoretically pas emissions :)
Well, i can try in 2 years, if it doesn't work i usually get a week to "fix" the car and i could just switch the exhaust manifold back to stock then :thumbup:

Greetz

Theres always FI...