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Thread: Back pressure *Update*

  
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    Patrick's Avatar
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    Back pressure *Update*

    It looks like I was right and the exhaust was causing excessive back pressure. Took the car to a Powerflow dealer at the weekend and had the twin outlet back box taken off and replaced by a single outlet.

    As soon as I drove off down the road the difference was amazing. Where as before you'd accelerate and you get power,slump,power,slump - it was more power,power,power. All I need now is a pre-cat and I think the exhaust route will be done with.
    - 2004 Vauxhall Zafira GSi - Silver, work in progress..
    - 2003 BMW 325ti M Sport - Silver, 18" CSL wheels in matt anthracite, Eibachs, Full red leather

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    so your a happy bunny now
    more power now

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    MikeWarner's Avatar
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    Sounds about right. Glad it is sorted. Even a normal twin pipe back box and cause a loss of power; I was told this when I got a custom made exhaust done by Maniflow in Salisbury - they deal mainly with motorsport stuff and they really know their stuff.
    8 Astras in a row! Can Anyone Beat That?
    Star Silver Astra Sporthatch SRi XP 1.9 CDTi (150PS)
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    Dual exit exhausts only work when the system is balanced correctly. Lots of 'twin' tailpipes just split in the silencer can at the end. I did this on my old Nova GTE, fitted a Janspeed and got 126 BHP, then chopped the tailpipe and added a 'dual DTM' tail end from Jetex. Power dropped to 108 BHP. Block one tailpipe and it came back up to 119 bhp. The turbulence created in the 'vee' was stalling gas flow. I modded the tail section and put in 'spoilers' to alter the flow and the engine clawed back to 126 BHP

    Mad but true!

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    BenC's Avatar
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    Most powerflow dealers know nothing about cars let alone making exhausts, they are just pipe benders and welders...
    Corsa C LEH 4x4?

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