stock downpipe versus aftermarket downpipe question
09-08-2009, 08:58 AM
#1
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stock downpipe versus aftermarket downpipe question
wondering what the hp gains are from stock downpipe with stock cat versus aftermarket downpipe with high flow cat. 5hp? 10 hp?
need smog and i think i am going to just swap back to stock.
thanks.
need smog and i think i am going to just swap back to stock.
thanks.
09-08-2009, 11:41 AM
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not that much gains really without further mods. yeah something like 5-10hp. The thing with making power with our cars is that components only become restrictive at certain power levels.
Great example is air intakes and intake manifolds. On Subarus these don't really matter until you get a lot of horsepower. And on the intake manifold, it seems not to matter much until you get like 600hp.
Cams and headwork too. On stock turbo and pump gas boost levels this makes barely any difference. Much more when the airflow is greater via more boost or bigger turbo.
Great example is air intakes and intake manifolds. On Subarus these don't really matter until you get a lot of horsepower. And on the intake manifold, it seems not to matter much until you get like 600hp.
Cams and headwork too. On stock turbo and pump gas boost levels this makes barely any difference. Much more when the airflow is greater via more boost or bigger turbo.
09-08-2009, 02:32 PM
#11
Last edited by kyoung05; 03-30-2011 at 10:14 AM.
09-08-2009, 02:51 PM
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If you're going to break the smog **** law you may as well go all out and get a catless setup! Think about it...its a 91 Legacy...pretty sure the popo isn't thinking you're out there street racing with grandma's grocery getter 
09-08-2009, 02:53 PM
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indeed....
doesnt matter if it has a cat thats more efficent or not...if it's aftermarket (ie made for performance and not an OEM replacement) it's illegal...doesn't even matter if it's catless and still is more efficient than stock....still illegal. F' CA in the **** for cars
doesnt matter if it has a cat thats more efficent or not...if it's aftermarket (ie made for performance and not an OEM replacement) it's illegal...doesn't even matter if it's catless and still is more efficient than stock....still illegal. F' CA in the **** for cars
