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Thread: Does any1 elses z20let feel alot slower on a hot day?

  
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    Arrow Does any1 elses z20let feel alot slower on a hot day?

    My astra runs cr@p on a warm day, The temperature gauge will go to about 90 and doesnt have as much power compared to a average day when the temperature guage is around 80,

    Does any1 else have the same sort of thing?


    Pav

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    Yup, was thinking that yeasterday when i went out topless (cabby), def felt slower... note signature !!

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    this is gonna sound really geeky....haha. But you are all definitely right. its because atmospheric pressure drops 1psi every 5 degrees celsius increase.

    So basically. air is not as dense on a hot day, so the turbo can't shove as much air in the engine = less power.

    A Car will be at its fastest on a cold dry night.
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    Especially crap if your sitting in traffic.

    Think mine is probably the worst at the mo as its sitting in the garage for its MOT tomorrow.

    So i'm in a 1.1 106. Slightly slower than an astra turbo on a hot day mind.

    Air temperature will affect turbo cars more as they need the air to be cooled after forcing it through the hot turbo.

    Generally though all cars are slower on a hot day

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    Quote Originally Posted by dharding02 View Post
    this is gonna sound really geeky....haha. But you are all definitely right. its because atmospheric pressure drops 1psi every 5 degrees celsius increase.

    So basically. air is not as dense on a hot day, so the turbo can't shove as much air in the engine = less power.

    A Car will be at its fastest on a cold dry night.
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    as charge temps get warmer performance gets slower
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    Well i thought it would have a bit of a drop in power but it seems to dropped loads,

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    Cold and damp is the best as far as I know, as above, air is denser when cold so more oxygen getting into the cylinders = bigger bang when ignited The dampness I think helps along the lines of water injection but I don't know enough about it to say overly why!

    I'd guess a warm day with abnormally low air pressure will make things worse still. Likewise a cold, damp day with abnormally higher air pressure will be better.

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    Rob R's Avatar
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    Will be even more noticable for those running the Rizzla thin standard intercooler !
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    The oxygen content of the warmer air is true, but not the biggest factor in a turbo engine's reduced performnace on a warm day.

    As the ambient temp increases so does the temp of the charged air that enters the engine from the turbo. The intercooler is less effective at reducing the charged air's temp and to compensate and keep the engine safe there will be more ignition retard (less spark to air/fuel volumes).

    This is why an efficient intercooler will help, but not cure the problem.
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