2000 E46 328ci Coupe - What parts are needed during supercharging - Page 4

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Thread: 2000 E46 328ci Coupe - What parts are needed during supercharging

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    #31
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    markrnorton's Car Details
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    Quote Originally Posted by DirtyTorquer View Post
    Reason most go for lower compression is the engine is originally designed as naturally aspirated, therefore has a relatively high compression ratio to a factory forced induction engine. The high compression is there to create more vacuum for the engine to 'suck' in the air it needs...and forced induction is well...forced.
    Yes the engine only sees the air pressure, but by also lowering the engines compression, you also increase the amount of air that can be forced into the combustion chamber during each cycle. More air and fuel offers bigger bang, more power and a nice smile on the driver's face. High octane fuel will reduce pre-det to a degree, but a proper hands on remap would be needed as the car would happily detonate itself to death given the chance
    Most of what you have written there is rubbish.

    High compression does not 'suck' more air in !! where did you get that from ? The reason turbo engines drop on compression ratio is that forced induction artificially raises compression and so can increase risk of detonation if not controlled properly.



    Also dropping the CR does not allow more fuel/air into the combustion chamber !! maybe a miniscule amount but not what your talking about.

    sorry to be so negative, but lets have straight facts. I've been using forced induction on cars for years.

    Boosting a standard engine does have pitfalls, but as you already start with a 'standard' CR you have a reasonable amount of performance to start with, without waiting for a turbo to spool up. slightly different with a S/C as its already supplying boost.

    My final set-up made close to 230hp at 10.4psi, generating 4.5psi at 2000rpm.

    Drop your CR and there will be a tail-off of initial pick-up, depending on how you size your turbo(s)
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    #32
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    DirtyTorquer's Car Details
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    OK I stand corrected then, but I did not say that it sucked more air in, I was refering to the manner of which it gets its air in compared to forced induction. It's fine to be negative
     
     

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