Rich, you're not considering the whole variables and theyr real influence.
We might find some formulas to roughly figure out kinetic and pressure values (don't have them handy at the moment so might not be neither easy nor quick) but I don't think this will be helpfull.
If your numbers where correct and doubling lenghts and volumes would only take 2mS this would mean the shorter layout will "respond" in a time about half that !!!!
Which is of course not (we're talking at least about 10ths of seconds if not seconds at all) and should already give you a sign there is something wrong with it.
From a "quality" point of view if you have 1 second lag at a given rpm and header layout, with a different one having about double the lenghts (and volume) you'll at least double the lag.
This is of course partially connected also to the INLET part of the sistem, which has to be compressed using the exhaust energy through the turbine impeller and then the compressor impeller, so that if you slower the reaction of the turbine of a given percentage you slower of something about proportional the intake build up of boost.
While lenghtening the runners you'll also loose some kinetic energy (which is the the most efficient energy transfer to the turbocharger) that will convert to heat than pressure than again to mechanical energy (loosing a lot of it through this passages).
Then you're not considering another important phisical aspect:
Pressure pulse travels at speed of sound BUT NOT THE CHARGE ITSELF (and to make an electric-electronic parrallel, it is just like ELECTROMAGNETICAL PULSE and REAL ELECTRON MOTION which is ~ speed of light vs. few cm per second);
Marco
We might find some formulas to roughly figure out kinetic and pressure values (don't have them handy at the moment so might not be neither easy nor quick) but I don't think this will be helpfull.
If your numbers where correct and doubling lenghts and volumes would only take 2mS this would mean the shorter layout will "respond" in a time about half that !!!!
Which is of course not (we're talking at least about 10ths of seconds if not seconds at all) and should already give you a sign there is something wrong with it.
From a "quality" point of view if you have 1 second lag at a given rpm and header layout, with a different one having about double the lenghts (and volume) you'll at least double the lag.
This is of course partially connected also to the INLET part of the sistem, which has to be compressed using the exhaust energy through the turbine impeller and then the compressor impeller, so that if you slower the reaction of the turbine of a given percentage you slower of something about proportional the intake build up of boost.
While lenghtening the runners you'll also loose some kinetic energy (which is the the most efficient energy transfer to the turbocharger) that will convert to heat than pressure than again to mechanical energy (loosing a lot of it through this passages).
Then you're not considering another important phisical aspect:
Pressure pulse travels at speed of sound BUT NOT THE CHARGE ITSELF (and to make an electric-electronic parrallel, it is just like ELECTROMAGNETICAL PULSE and REAL ELECTRON MOTION which is ~ speed of light vs. few cm per second);
Marco
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