10-02-2018, 07:47 AM | #23 |
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All I hope for is the AA midpipe and an axleback that will have a deeper tone.
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2019 M2C DCT | Alpine White
Full AA exhaust (catless DP/signature exhaust) | M Performance Coilovers | Need to find some new wheels! |
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10-02-2018, 08:06 AM | #24 | |
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I've been reading up on the technology and GPF's (English name for OPF) (both upfront-with-CAT "VW style", or separate-under-car "BMW style") have only passive regeneration. They use oxygen present only under overrun conditions to ignite soot in the GPF and burn it off naturally under normal conditions with normal exhaust gas between 400-700degC. In cold / constant speed situations the DME will retard ignition to heat the exhaust gas flow and run it lean to allow oxygen to increase in the exhaust gas and start regen that way. No fuel is passed to the GPF as far I can see, so it should not cause any "popping" - but this maybe due to other reasons like a different DME map for OPF cars? As EU & US cars have the same rear silencer, only the US secondary CATs or EU OPFs can make the difference sound wise. Be interesting to hear US cars with secondary CAT delete to compare... Anyway, nice exhaust phil_m2, it sounds / looks great looking forward to price and availability.... Last edited by doughboy; 10-02-2018 at 08:15 AM.. |
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10-05-2018, 05:21 AM | #25 | |
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Just remove the OPF and find out! |
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10-05-2018, 05:26 AM | #26 |
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I don't doubt your judgement that it sounds awful! I'm thinking of tuning benefits of removing secondary cats (US) / OPF (EU) for better gas flow.
Maybe a full downpipe back system would need more silencing in the back silencer to tone things down a bit? Be interesting to see what a variety of exhaust manufacturers come up with over the next few months... |
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