OE exhaust piping size

hawk02

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For all those saying that Magnaflow and now Borla using 2.25 inch piping is the same as stock......it's not, OE is 2 inch as just tested and released in a blog from 27WON performance, they are using 2.5 inch and have some nice info on their site and they have no resonator in the mid pipe and a very small muffler with resonator piping off the main system for drone. System looks gorgeous and should sound awesome, follow their blog on their site...........
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hawk02

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hawk02

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Mid pipe to me is the pipe traveling down the MIDDLE of the car not the DP/front pipe combo..........
 

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Where do you see a custom 2.5" mid-pipe with no resonator? They fabricated a muffler section which bolts up to stock mid-pipe at rear axle.
 
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hawk02

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Where do you see a custom 2.5" mid-pipe with no resonator? They fabricated a muffler section which bolts up to stock mid-pipe at rear axle.
OH boy, read the whole blog.................it's not just an axle back and there is no connection there, the OE exhaust is 1 piece front to back......
 
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hawk02

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The OE exhaust system uses very small 50.5mm (2in) piping for the entire exhaust system. This is just not ideal for a performance exhaust system, especially one for a turbocharger equipped engine; in fact the OE 50.5mm exhaust is close to its maximum power capacity before substantial power loss will occur due to the flow restriction.
 
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hawk02

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With this knowledge, we opened up the exhaust piping to 63.5mm (2.5in) to help move the exhaust out of the engine more efficiently.
Going from 50.5mm to 63.5mm provided a 58% increase in cross-sectional area of the exhaust piping.
 
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hawk02

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And I asked the owner on FB about using a resonator in the intermediate pipe and he said they did NOT
 


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hawk02

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Honda Civic 10th gen OE exhaust piping size dscn0055_zpsk38vtrww-
This a DP/front pipe combo, mid pipe is next and part of a "cat back" system
 

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Not trying to thread jack, but we just dyno tested our shop car again yesterday to see if the factory exhaust was restrictive on a tuned bolt-on (catted dp/fp, FMIC kit, CAI and KTuner) car in hopes to milk more power out of it. We dropped the stock exhaust after our 3" front pipe and saw a no recordable power gains at 255-265 hp and 315 tq. Unless your goals are to simply improve exhaust tone (which we fully support :thumbsup:), we have yet to find any power gains from improving exhaust flow after the front pipe.



Sound clips for reference, please excuse the cellphone quality Facebook video. :(
 

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Needed to post here for personal reference. I keep trying to get back to this dyno result after coming across more exhaust threads. Easier for me to find now. :)
 

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Not trying to thread jack, but we just dyno tested our shop car again yesterday to see if the factory exhaust was restrictive on a tuned bolt-on (catted dp/fp, FMIC kit, CAI and KTuner) car in hopes to milk more power out of it. We dropped the stock exhaust after our 3" front pipe and saw a no recordable power gains at 255-265 hp and 315 tq. Unless your goals are to simply improve exhaust tone (which we fully support :thumbsup:), we have yet to find any power gains from improving exhaust flow after the front pipe.


Bringing this back from the dead again because people keep referencing this dyno run. And honestly, I couldn't remember where I read it from but my memory is lacking so I don't count. :p It's good to keep this info in the limelight.

I am posting the pic below so people get a visual of the piping transition that's being talked about above. There was no recordable power gains at 255-265hp when the stock piping (brown exhaust piping on right side) was removed. Just putting this up for reference.
Honda Civic 10th gen OE exhaust piping size dsc02429_zpsyx7inai2-
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