Replying to Topic 'Exhaust mods on I4'
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Originally posted by Sigvard
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Originally posted by Kranberry
Already tuned seems like a relative term. I mean you could tune the exhaust more by changing the muffler. Removing the 2nd cat. All sorts of ways.
You can take a stock car with no tuning and buy an intake and it'll help a bit, but it'll be better with a performance muffler. Still a header would help and so would every piece. Each item you upgrade to the intake/exhaust system will help. You will see gains from each piece added. So you could get an intake and not touch the muffler, but if you were to change that, then you would see improvements.[/b]
Seems like you're in a muffler business

.[/b][/quote]
Actually no, and I'm not a post whore so I'll respond to your other post...
You are correct that one component such as exhaust without changing intake would not maximize your return because of restrictions onthe intake. But every little bit that you change helps.
Of course having someone actually tune parts for a particular engine is the best, but short of that, bolt on modifications such as a muffler or intake can make some changes. Although if you have a restriction in the ECU then you are not maximizing on the intake/exhaust mods. What I was trying to get at was that although it is tuned, it is tuned for the parts in the system. There are pretty much always room to improve a stock engine, such as cams, pulleys, pistons, port polishing, etc...every little bit helps even if it isn't cost efficient. I mean if you were to say get 6HP from an exhaust but that exhaust costs you $700 then you are paying around $116/HP, while lets say a cheap intake costs you $180 but nets you 3 HP, then you are paying $60/HP. But let's say you got both and it netted you 10HP, you might gain more HP by both being in there. But it is all unknown as to any gains you get as it depends on the engine.