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Exhaust wrap- where to buy, what thickness?

Discussion in 'Businesses and Service Providers' started by SpaceMonkey, Dec 19, 2013.

  1. Pretty simple question - anyone want to hook a brother up with the cheapest place to buy exhaust wrap? Also whats the best thickness and how much length to use on pretty small headers? (2 into one, about 35mm diameter)

  2. #2 pwbike, Dec 19, 2013
    Last edited: Dec 19, 2013
    That shouldn't be under 'Bling and appearance'.
    The purpose of the thermal wraps and ceramic coatings is to retain heat and increase engine efficiency. I'm trying to remember who it was that started doing it, Gale Banks, Carol Shelby?

    Did some more looking, I think it may have been Smokey Yunick who first started using it on hotrods as a means to increase power.
  3. I thought about that and where to put this post, but I'm being honest here- the exhaust being wrapped is on a cafe racer, so it's definitely bling and appearance, I'm pretty sure all those wrapped exhausts on the Deus bikes make sweet-fa difference to how they go.
    • Agree Agree x 1
  4. I bought my wrap at Auto Barn. Not sure how much you'll need thou.
  5. Sweet mang, I've seen calculators online that estimate the required length. How much did you buy and price? And what bike was yours on?
  6. Can't remember how much I paid or what length I got, it was a few year's ago.
    But I have xvs650 with Vance & Hines cruisers on it.
    I doubt it makes any difference to the performance of the bike but I like the look of it.
  7. Easy fast way to trap water and cause corrosion of the exhaust system
  8. Don't confuse the issue with facts.

    SpaceMonkey wants the style, and bloody good luck to him. :)

    It may not be your style. It may not be my style.

    So what?
    • Agree Agree x 1
  9. Whilst it could be argued that it's a performance modification for a car, by reducing under-bonnet temperatures, it's actually the opposite for bikes.

    The exhaust systems on bikes form party of the cooling system. Wrapping them up means more heat will be retained by the head and that means lower performance (not to mention reliability).

    Then there is the fact that higher temperature gas has a larger volume, thus it inhibits exhaust performance.
  10. Shouldn't be a problem, the GN250 didn't come with any performance anyway....

  11. I'm sorry but that is wrong, it was never about reducing under-bonnet temps originally (it may help that way in modern vehicles).
    By retaining the heat of the exhaust, the gas velocity is maintained and better cylinder scavenging results. A bike engine is no different to a high performance car engine, it dies not need the exhaust to function as a "cooling system" or part thereof.
  12. Common repetition of falsehood might equate to a government in Australia, but it doesn't equate to engineering fact.

    Air cooled motors very much rely on the heat dissipation of the exhaust system for cooling. This is why the old british twins used to stick the headers out the side, rather than in front of the engine.

    I would argue that even water cooled bikes rely on it also, because the water cooling systems aren't great.
  13. Supercharged aircraft engine with stub headers?
    No cooling there.
    I'm not making this up, it's a known phenomenon, it's not a big increase in power, but when everything else is done it is a bit more for not much effort.
  14. Oh Im fully aware of what is common motoring understanding. But like quite a few other motoring understandings, ICB.

    The mass flow is the same. The velocities are higher, but the density is lower.

    If they trully thought about what they were saying they would be advocating the smallest header diameter without going supersonic.

    And aircraft engines don't make a lot of power compared to the fin area. And they run in cold air at high speeds. They don't need the extra cooling.

    Bike engines make a lot of power for their capacity and they sit stationary in traffic.

    Don't worry, I used to make the same argument as you too, until I stopped and thought about it. Then I realised that most of the time I'd read about it was when the article was plugging header coatings.
  15. Well I've never done my own tests and it originates back in the 50's or 60's so maybe there are better ways to get some extra horsepower these days.