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    why does engine power fluctuate so much. ?

    2.0 Honda prelude 133 BHP
    2.2L VTEC Honda prelude 195 BHP

    why is there so much difference , the only thing notibaly different is " VTEC " , and a 0.2L gain ?.
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    VTEC (Variable Valve Timing and Electronic Lift Control)
    It gives more PPPPPOWER!!!!!!
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    Might be a turbo, check the rest of the specs?
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    Tuning

    Chevy V8 7ltr + maybe 300bhp, Jaguar 4.2 Supercharged V8, 420bhp.

    Its all about the tuning. Although the Chevy will obviously have more torque due to its size.
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    If you compare like for like between the same manufacturer then theres more of a trend. Take GM NA Ecotec units for example:

    1.4 16v ~ 90bhp
    1.6 16v ~ 105bhp
    1.8 16v ~ 120bhp
    2.0 16v ~ 134bhp
    2.2 16v ~ 146bhp
    2.5 24v ~ 167bhp
    3.0 24v ~ 207bhp

    The 16v motors are all basically the same block just bored out, likewise with the 24v motors. Hence more cc = more bhp (and torque). However the forced induction units break the pattern:

    1.6 16v T ~ 192bhp
    2.0 16v T ~ 240bhp
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    (Original post by obnoxious)
    why does engine power fluctuate so much. ?

    2.0 Honda prelude 133 BHP
    2.2L VTEC Honda prelude 195 BHP

    why is there so much difference , the only thing notibaly different is " VTEC " , and a 0.2L gain ?.
    the only way to understand it is to learn the basics of how an engine functions.
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    (Original post by gbduo)
    Tuning

    Chevy V8 7ltr + maybe 300bhp, Jaguar 4.2 Supercharged V8, 420bhp.

    Its all about the tuning. Although the Chevy will obviously have more torque due to its size.
    Careful Graham! Power = torque x speed, so if the Chevy has more torque but a lower peak power then either it can't rev as fast or the torque drops off faster than the Jag. At the end of the day it's the shape of the torque curve and the power available that are important - the rest is a matter of gearing. I know you probably know all that but your statement wasn't very clear!
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    (Original post by CurlyBen)
    Careful Graham! Power = torque x speed, so if the Chevy has more torque but a lower peak power then either it can't rev as fast or the torque drops off faster than the Jag. At the end of the day it's the shape of the torque curve and the power available that are important - the rest is a matter of gearing. I know you probably know all that but your statement wasn't very clear!
    Yeh, thanks for clearing that up
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    you can get 400bhp out a 2.0 evo nowadays, so engine size/power doesnt necessairley work.
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    (Original post by Mattgeezer)
    you can get 400bhp out a 2.0 evo nowadays, so engine size/power doesnt necessairley work.
    you can get alot more than that from race tuned engines. a 2.4 F1 engine produces around 800bhp.
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    (Original post by Lara C.)
    you can get alot more than that from race tuned engines. a 2.4 F1 engine produces around 800bhp.
    i was on about stock cars,
    there was that guy who tuned up a 2.5(iirc) calibra to over 1000 bhp
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    Never heard of a Z20LET with 1000bhp.


    RB26s and 2JZ-GTE's regularly see over 1K though.
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    (Original post by Friggerpants)
    Never heard of a Z20LET with 1000bhp.


    RB26s and 2JZ-GTE's regularly see over 1K though.

    Z20LET is the turbo unit found in the Astra G, Zafira A. C20LET and C25XE/X25XE are the turbo unit and NA V6 found in the Calibra.

    And I find it extremely hard to believe anyone got 1000bhp from a 25XE seeing as they don't last 5 mins with a turbo unless a massive amount of money is spent. But even with a turbo it'd only make about 250-300bhp.
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    (Original post by Lara C.)
    you can get alot more than that from race tuned engines. a 2.4 F1 engine produces around 800bhp.
    even more impressive was the 1.5 turbo engines in F1 cars in the 1980's, some of them had well over 1,000bhp!:yep:
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    (Original post by djchocice)
    even more impressive was the 1.5 turbo engines in F1 cars in the 1980's, some of them had well over 1,000bhp!:yep:
    The Quali engines had peak power of over 1,400bhp, but didn't last very long!
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    (Original post by Friggerpants)
    (Original post by Mattgeezer)
    i was on about stock cars,
    there was that guy who tuned up a 2.5(iirc) calibra to over 1000 bhp
    Never heard of a Z20LET with 1000bhp.


    RB26s and 2JZ-GTE's regularly see over 1K though.
    It's an Opel Omega.... but its got a 1UZ-FE not a Vauxhall/Opel engine.

    Article
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    (Original post by Powerful_Robot)
    It's an Opel Omega.... but its got a 1UZ-FE not a Vauxhall/Opel engine.

    Article

    Good read that, a massive amount of work has gone into it. As I said above, the GM V6 would produce no where near this amount of power, but a forced v8 would, lol.
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    (Original post by Lara C.)
    you can get alot more than that from race tuned engines. a 2.4 F1 engine produces around 800bhp.
    And lasts a couple of races before something goes wrong....

    The 400hp from the 2.0 litre Evolution was about as reliable as it gets with their 3 year warranty.

    It also depends on how the engine is quite obviously built, i.e. the Honda VTEC or Ford ZETEC engine are two very good examples of this.
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    (Original post by Né Stig)
    And lasts a couple of races before something goes wrong....

    The 400hp from the 2.0 litre Evolution was about as reliable as it gets with their 3 year warranty.

    It also depends on how the engine is quite obviously built, i.e. the Honda VTEC or Ford ZETEC engine are two very good examples of this.
    so? theres surely a correlation between how much power and engine is tuned to produce and its life span.

    and btw the FQ-400 still has a stupidly short service interval. something like 4-5k miles i believe.
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    (Original post by Né Stig)
    The 400hp from the 2.0 litre Evolution was about as reliable as it gets with their 3 year warranty.
    and 4.5k service intervals! The mitsibushi warranty is also pretty worthless, they will try and wiggle out of all claims in any way possible. And unfortunately reliability of the 400s has been a bit of an issue for many.

    Apparently the X is going to be significantly better though.
 
 
 
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