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im bored....and this goon keeps e-mailing me about how well his 'e-boost' is working, so i thought i;d clear this all up for anyone who might think its true, feel free to input any information, etc:
Ok before I go into this e-boost stuff, let's look at the concepts of turbocharging/supercharging/boosting in general
we all know that an engine digests air that, when combined with gasoline, is used to make the powerful explosion inside an internal combustion engine. The more air = the more fuel that can be added which in turn, makes a higher pressure inside the combustion chamber resulting in a higher power stroke and in turn creating torque to the crank. Now, as you may or may not know…horsepower is only a measurement of torque at a given RPM, and a higher torque at a given rpm = more power.
this explains that more combustion pressure during the power stroke in turn makes more power. But we have a 4 stroke engine now, so what about the other 3? Before the engine can make power (power stroke) there is the compression stroke. And before that, there is the intake stroke. And after compression is the exhaust stroke. During the intake stroke, the piston moves down in the bore, creating a lower than atmospheric pressure. The pressure outside of the cylinder (atmospheric) is now higher than the pressure inside the cylinder so in turn, air flows into the cylinder to fill it. Contrary to what some of you may think about the workings of an internal combustion engine, the piston itself DOES NOT suck air into the chamber. It does not happen. Skrilla made a post about this a while back. I actually got it wrong, and since then….learned up. Like I said ^^^ the greater the amount of air that fills the cylinder, the higher the pressure inside the combustion chamber will be (after the compression and power stroke that is), ok so now that all that nonsense is out of the way…let’s move on:
im sure you might be familiar, or have at least heard of the term ‘volumetric efficiency’ volumetric efficiency (VE) is used to describe the amount of fuel/air in the cylinder in relation to regular atmospheric pressure. If the cylinder is filled with fuel and air at atmospheric pressure (14.7psi) then the engine is said to have 100% volumetric efficiency. In a 2 liter four cylinder like our 420a, each cylinder has a volume of 499.18cc. ok this is how I got that:
Our engine = 121.8cu in
1cc = 0.061 cubic inches
121.8 cu in divided by 0.061 = 1996.72cc, so truly not in “fact” a 2 liter yet.
the 420a being a 4 cylinder means 1996.72cc/4cylinders = 499.18cc of air per cylinder (at 100% VE)
if one cylinder breathes in 424cc on the intake stroke, the engine is said to have an 85% volumetric efficiency (typical of most 420a’s) ( 424cc/499.18cc = 0.849 or 85% rounded up). Volumetric efficiency will change with a lot of different things such as how good the intake ports flow, how large they are, cam profiles, valve timings, etc. lets just say a 420a has a 85% VE. If a 420a 2 liter revving to 7200 rpm WOT, redline, this means that it eats 7188.2L of air per minute (one intake stroke to every two rpm), or 119.8 liter per second. Another way to look at it this flow is in cubic feet per minute and, and since 1cc = 0.061cu in and 1 liter = 1000cc each minute this engine consumes a approximately 254 cubic feet of air per minute. now….. a little 60mm diameter PC cooling fan flows only about 18 cubic feet per minute. Think about it this way….it would take over 14 60mm fans working hard just to feed this 2 liter, and that’s not even creating any boost.
*People confuse BOOST with AIRFLOW, if you don’t ever go above 14.7psi, you are not boosting. You might only see power because of the increase in VE, a vivid example is vtec (variable valve timing focused on scavenging principles and different rockers and lift durations)
so whats some ways to improve an VE? The best way is ‘forced induction’, causing a VE of OVER 100%, a variable valve timing like vtec does the same thing to a certain extent. But who cares about vtec? I wont go into it. Point is, If you have more air in the engine than it can even can consume, you have a boost pressure. Increasing VE to 120, 180, 200% means that much more fuel which means that much more power
now…..e-boost:
it connects and runs off the 12 volt on the battery. As you know…supercharging robs some power from the motor, and a highly efficient supercharger takes about 14.5kw to run. It steals this from the power generated to the crank due to the power stroke. On the other hand…to have an electric motor that runs off the 12 volt battery generating that many watts (14000+) we'd need a current flow of at least 1000 amps (14,000+ watts/13.8 volts = 1050 amps. So for this to even work….you’d need like 10 alternators!!! Let alone a serious fuckin compressor, not a fan
So remember kids…airflow does NOT equal boost, e-turvo can die a healthy death now, k thanks.
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96 talon esi-t
san clemente, ca
as needles of ice
are the ill winds' talons
the coldest of shadows
they seep unto the bone
silent souls leave .308 holes
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