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Thread: HotPipes Exhaust Header from Speedlab

  1. #11
    Still Plays With Cars Loren's Avatar
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    Quote Originally Posted by IchabodCrane View Post
    Is it worth 6 or 7 hp if you're taking a significant hit in economy?
    Yes, even if I took a "significant" hit in fuel economy, it's totally worth it to me. I bought the car to autocross because it's very lightweight. Great fuel economy is a side benefit, not a requirement.

    But, it's not going to cause a reduction in fuel economy UNLESS it causes me to change my driving style. If I continue to semi-hypermile in my daily driving, I'll continue to get nearly the same MPG, and possibly better.

    A properly designed header and exhaust IMPROVES the efficiency of the engine. Why doesn't the factory do it that way? Because they're working to a budget, they're making the exhaust as cheaply and simply as they can. Because they're watching the weight, they want the car to be as light as it can be. And because they have to meet certain emissions requirements, which is why the car has two catalytic convertors, and the first one is VERY close to the combustion chambers (which prevents proper exhaust manifold design) so that it "lights off" as early as possible on a cold start.

    In short, I'm redesigning the exhaust to a different price point and to a different set of compromises.



  2. #12
    Moderator Eggman's Avatar
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    Quote Originally Posted by IchabodCrane View Post
    Is it worth 6 or 7 hp if you're taking a significant hit in economy?
    For racing, the answer is yes. Fuel efficiency is not the object.

    Quote Originally Posted by Loren View Post
    A properly designed header and exhaust IMPROVES the efficiency of the engine. Why doesn't the factory do it that way? Because they're working to a budget, they're making the exhaust as cheaply and simply as they can. Because they're watching the weight, they want the car to be as light as it can be.
    All good points. There are manufacturers using headers (Chrysler era AMC 4.0 I-6 comes to mind). Mitsubishi isn't saving any weight using a cast-iron exhaust manifold though.

    Still, it'll be cool to see how yours turns out.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)


  3. #13
    Still Plays With Cars Loren's Avatar
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    Quote Originally Posted by Eggman View Post
    Mitsubishi isn't saving any weight using a cast-iron exhaust manifold though.
    I believe the Mirage manifold is actually made of stamped steel pieces welded together. But, a lot of times they'll make a manifold from cast iron just because it's SO much cheaper to make them that way rather than by fabricating individual tubes.

    It's all about priorities. Performance. Reliability. Fuel economy. Cost. All have to be balanced to what the car's intended market is. The bean counters always win.

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    Senior Member Subcompact Culture's Avatar
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    Did you ever do this, Loren?

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    Still Plays With Cars Loren's Avatar
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    Yeah, I did the SuperCircuit header and a custom cat-back.

    https://mirageforum.com/forum/showth...rmance-Exhaust
    Simplify and add lightness.

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    Senior Member Wallythacker's Avatar
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    Quote Originally Posted by IchabodCrane View Post
    Is it worth 6 or 7 hp if you're taking a significant hit in economy?
    what we (I) don't know is if the stock Mirage system creates enough back pressure to affect mileage. In many cases free flowing systems can increase mpg as well as hp. Case in point, my 429 Mustang returned 25mpg with both mufflers blown off.

    Anyhow if a group discount can be worked out I'd be interested in a header. We usually fly to FLorida each summer for breakfast, I might as well make it a little more worthwhile.
    Zero, 2014 ES Plus 5MT, written off but not forgotten.
    Zero II, 2014 SE, 5MT, climate She's HOME now!
    Shelby AKA "Cute", 2017 ES 5MT, A/C.

    Mirage owners look at the world differently than everyone else, but in a better way
    We're driving the Beetle of the 21st century, the greatest small car now available!

        __________________________________________

        click to view fuel log View my fuel log 2017 Mirage ES PLus 1.2 manual: 39.0 mpg (US) ... 16.6 km/L ... 6.0 L/100 km ... 46.8 mpg (Imp)


  8. #17
    Just A Mirage!
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    Quote Originally Posted by Wallythacker View Post
    We usually fly to FLorida each summer for breakfast
    Must be some really good breakfast!

    I'd totally be interested in a group buy as well.

        __________________________________________

        click to view fuel log View my fuel log 2017 Mirage GT 1.2 automatic: 37.5 mpg (US) ... 15.9 km/L ... 6.3 L/100 km ... 45.0 mpg (Imp)


  9. #18
    Member Alemon's Avatar
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    Speedlab headers

    I bought a speedlab headers and a new exhaust manifold gasket. Part# 1555A650. Is this the correct gasket for Mirage 2018+. They do not conform to the shape of the header/ gasket overlaps. Is my header incorrect or is it the gasket? Have not pulled out the OEM exhaust manifold yet to verify this and get someones advice first. There is also this gasket but i am not sure if it is compatible with 2018+ engine
    https://www.ebay.ca/itm/124599151713

    https://youtu.be/oTOQE9Ma54g
    @1:02

    Thanks
    Attached Images Attached Images      

  10. #19
    Senior Member Qrush's Avatar
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    At 1st glance, that looks incorrect. I don't recall the part# for the gasket. However, you can use the original and it shouldn't make a difference.

  11. #20
    Member Alemon's Avatar
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    Refer to this photo. Do you know if this engine is 2017+. I asked this because the exhaust manifold gasket matched the gasket attached to this engine. On Mitsubishi website Part# 1555A650 shows compatibility with 2017+ mirage models. The speedlab flange is does not conform to the gasket/gasket overlaps the smaller hole. I was told by speedlab that this gasket would still work and their new headers would fit 2017+ mirages with stock exhaust. What is the small hole by the exhaust port?


    Attached Images Attached Images  
    Last edited by Alemon; 07-23-2021 at 03:46 PM.

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