Page 8 of 8 FirstFirst ... 678
Results 106 to 116 of 116

Thread: Hp displacement ratio

  1. #106
    Join Date
    Dec 2005
    Posts
    1,200
    It was a typo when I wrote F=Mx(AxA)

    Then he asked what A stood for.. that is when I said "Force is equal to mass times acceleration squared"

    it was a joke... Because I knew that I had written it wrong and him asking what A stands for (because if A=acceleration then F=Mx(AxA) is wrong)

    get it? It is pretty lame...
    Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
    Engine torque is an illusion.

  2. #107
    Join Date
    Nov 2004
    Location
    UK
    Posts
    2,734
    Quote Originally Posted by hightower99
    It was a typo when I wrote F=Mx(AxA)

    Then he asked what A stood for.. that is when I said "Force is equal to mass times acceleration squared"

    it was a joke... Because I knew that I had written it wrong and him asking what A stands for (because if A=acceleration then F=Mx(AxA) is wrong)

    get it? It is pretty lame...
    no way.

    how do you mistype F=Mx(AxA)... there are brackets in it!!
    you were also trying to clarify a previous incorrect statement!
    How can men use sex to get what they want?
    Sex is what they want. - Frasier

  3. #108
    Join Date
    Dec 2005
    Posts
    1,200
    Quote Originally Posted by derekthetree
    no way.

    how do you mistype F=Mx(AxA)... there are brackets in it!!
    you were also trying to clarify a previous incorrect statement!
    If you want to discuss this use the PM system...


    It was a typo I am not accustomed to using a forum text application to write formulas. Having a keyboard with four functions per button doesn't help much either.


    High HP/L doesn't make an engine better than others
    likewise an engine with a lower HP/L doesn't mean it is worse.
    Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
    Engine torque is an illusion.

  4. #109
    Join Date
    Apr 2003
    Location
    St Marys Western Sydney
    Posts
    20,953
    Quote Originally Posted by hightower99
    High HP/L doesn't make an engine better than others
    likewise an engine with a lower HP/L doesn't mean it is worse.
    Say what you want, but when displacement is the primary factor affecting power and torque, people will always draw conclusions. Nobody in their sane mind uses HP/L as anything more than a gauge for comparing various engines and how effective they are at making power.
    I am the Stig

  5. #110
    Join Date
    Feb 2006
    Posts
    95
    Quote Originally Posted by fpv_gtho
    Say what you want, but when displacement is the primary factor affecting power and torque,

    I would rather say that airflow is the primary factor affecting power and torque.

    Foreced induction affect air flow (increasing hp and torque)

    Increased cylindervolum affect air flow(increasing hp and torque)

    Airflow is the factor deciding how mutch fuel can runn trough the engine and therfor deciding the power and torque.

    By the way I think the answer is gasturbines with the late f1 turbo engines from the 80's as runner up.

  6. #111
    Join Date
    Mar 2005
    Posts
    1,508
    The late 80s turbos were quite impressive though at least part of their very high HP/L was due to the very volatile fuel they used. Those engines would not have produced as much power on the fuel run in F1 today.
    Also, just about tying the F1 cars are the current crop of Top Fuel motors. They can produce upwards of 8000+ hp out of 8L of displacement. They also run on a very volatile fuel. Not bad for a pushrod motor and certainly the most powerful of the series race motors (not counting things like the salt flat cars or the tractor pull guys who use lots of motors).

  7. #112
    Join Date
    Dec 2005
    Posts
    1,200
    Quote Originally Posted by stian1979
    I would rather say that airflow is the primary factor affecting power and torque.

    Foreced induction affect air flow (increasing hp and torque)

    Increased cylindervolum affect air flow(increasing hp and torque)

    Airflow is the factor deciding how mutch fuel can runn trough the engine and therfor deciding the power and torque.

    By the way I think the answer is gasturbines with the late f1 turbo engines from the 80's as runner up.
    I would have to say VE is the primary factor affecting Torque and that RPM is the primary factor of Power. You need to use both. The physical displacement of an engine has little to do with it's torque or power, and airflow only gives you a theoretical "ballpark" max figure for both.


    VE tells you exactly how much air you have in the cylinders after all the valves are closed to actually burn any fuel, thus telling you how much torque can be made.

    Torque is however meaningless with out a time componant and that is where RPM comes in, giving you a Power figure.

    If you want to check this try looking at a VE over RPM graph beside a Torque over RPM graph and notice that they have the same shape.
    Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
    Engine torque is an illusion.

  8. #113
    Join Date
    Nov 2006
    Location
    Aberdeen
    Posts
    2,975
    Quote Originally Posted by hightower99
    The physical displacement of an engine has little to do with it's torque or power
    i kind of disagree:
    pb= bhp
    bmep=...you know, its related highly to torque
    Vd=displacement
    N=rpm
    X=2 for for 4 stroke, 1 for 2 stroke
    Attached Images Attached Images
    autozine.org

  9. #114
    Join Date
    Dec 2005
    Posts
    1,200
    Quote Originally Posted by jediali
    i kind of disagree:
    pb= bhp
    bmep=...you know, its related highly to torque
    Vd=displacement
    N=rpm
    X=2 for for 4 stroke, 1 for 2 stroke
    Yes that is used when you don't know the VE.

    You need to know the displacement but the VE is the key.

    Also the BMEP is also a great thing to know (especially for exhaust tuning) But it is only a ballpark figure.
    Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
    Engine torque is an illusion.

  10. #115
    Join Date
    Nov 2006
    Location
    Aberdeen
    Posts
    2,975
    Quote Originally Posted by hightower99
    Yes that is used when you don't know the VE.

    You need to know the displacement but the VE is the key.

    Also the BMEP is also a great thing to know (especially for exhaust tuning) But it is only a ballpark figure.
    There are a few efficencies that can act as multipliers of this expression for power, one of these is VE. bmep is vital! this is an instantaneous (not integral) equation therefore has its limitations but it cannot be ignored. can you describe an expression (or show one) that does not include rpm, bmep and displacement? power is more than VE..VE is an optional part of this equation... so what do you use when you know the VE? ignore N,X,bmep and Vd? i would doubt it.

    EDIT; i just reminded myself the bmep equation at the bottom of my picture includes VE as a necessary value.
    Last edited by jediali; 12-05-2006 at 08:37 AM.
    autozine.org

  11. #116
    Join Date
    Dec 2005
    Posts
    1,200
    Yeah VE is a necessary value to calculate BMEP. To figure the power of an engine all you need to know is what torque it produces at what rpm.

    If you use imperial units then HP=(Torque in lbs-ft*RPM)/(16500/Pi)
    If you use SI units then W=(Torque in Nm*RPS*2*Pi)
    Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
    Engine torque is an illusion.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. American Muscle...from 1957
    By BMW325 in forum Car comparison
    Replies: 34
    Last Post: 12-28-2009, 04:18 PM
  2. Toyota Avensis (T250) 2003-2009
    By dracu777 in forum Matt's Hi-Res Hide-Out
    Replies: 27
    Last Post: 05-30-2006, 01:08 AM
  3. Replies: 13
    Last Post: 09-16-2005, 03:44 AM
  4. Battle of the hatches
    By dcsbeemer in forum Car comparison
    Replies: 25
    Last Post: 07-28-2005, 03:46 PM
  5. variable compression ratio
    By KnifeEdge_2K1 in forum Technical forums
    Replies: 19
    Last Post: 09-01-2004, 11:02 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •