Quote:
Originally Posted by SkullWorks
@ robispec to much foreshadowing...you are making me tired already, extra redbull
As far as the MANIFOLD PRESSURE vs FLOW issue that is kind of taking place on this page today, there are 2 variables no one has brought up yet that are very important.
First, the boost a car sees (MANIFOLD PRESSURE) is a measurement of restriction to flow created by the intake runners/valves/head/cylinder capacity....not just cylinder capacity. my sr20VET and DET make vastly different HP at the same boost level, because there is less restriction in the runners/valves/heads the motor see's less "boost" but is getting the same MASS of air...that's what counts.
second...Direct injection and E85 both contribute significantly to the charge cooling happening in the runner...wait...i mean combustion chamber...that's where it gets silly, you can actually inject enough E85 directly into the cylinder to lower the pressure in the cylinder decreasing boost or in the case of an NA motor actually generating greater than 100% VE (volumetric efficiency)...which is astounding.
TLDR; Boost is a lie, boost doesn't mean more airflow and the better the NA motor is when you put the boost to it the more power you will make per PSI, MASS flow is what matters, (usually given in CFM or lb/min) |
DING DING DING!! We have a winnar!
Boost is meaningless. Fuel doesn't combine with boost, it combines with air. What matters is how much AIR is geting pushed into the cylinders, not what pressure it's at (on the way in).
Now, granted, you can use boost to judge the amount of air, but only on the SAME engine. Cramming 1L of air into a .5L bottle will get you 1 bar of "boost" (roughly), but cramming that same amount of air into a 1L bottle means 0 bar. Yet when ignited, it has the same energy potential. And this isn't taking into account compression, timing, VE, etc.