how many CFMs can this engine take?
10-11-2005, 07:44 PM
#1
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how many CFMs can this engine take?
I am just wondering because I was thinking about getting one of those electronic superchargers just for the hell of it and I found one that puts up to 1200 CFM and pushes 3psi of boost for $100 shipped. I know I know what a piece of junk but a dyno does not lie right?
If I could get an extra 20HP it would be worth it plus the more stuff I put on the car the more HP grows.
The plan is CAI (installed), exhaust (installed), Voltage regulator (installed), grounding kit (ordered), bored MAF (later), bored TB (later), injectors (later), nology (installed), NGKs (installed), Vortex Booster (want), s4 fuel pump (want), unorthodox pulleys (want), stand alone (want), remapped ECM (installed), Hi flow cat (want).
So Can I install all of this stuff without messing up the engine?<ul><li><a href="http://cgi.ebay.com/ebaymotors/Electric-Supercharger-TURBO-All-Makes-and-Models_W0QQitemZ8006665864QQcategoryZ33741QQssPage NameZWDVWQQrdZ1QQcmdZViewItem">Supercharger</a></li></ul>
If I could get an extra 20HP it would be worth it plus the more stuff I put on the car the more HP grows.
The plan is CAI (installed), exhaust (installed), Voltage regulator (installed), grounding kit (ordered), bored MAF (later), bored TB (later), injectors (later), nology (installed), NGKs (installed), Vortex Booster (want), s4 fuel pump (want), unorthodox pulleys (want), stand alone (want), remapped ECM (installed), Hi flow cat (want).
So Can I install all of this stuff without messing up the engine?<ul><li><a href="http://cgi.ebay.com/ebaymotors/Electric-Supercharger-TURBO-All-Makes-and-Models_W0QQitemZ8006665864QQcategoryZ33741QQssPage NameZWDVWQQrdZ1QQcmdZViewItem">Supercharger</a></li></ul>
10-12-2005, 02:04 AM
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Re: how many CFMs can this engine take?
If you look at the chart they supply and lookup 170 cu in (2.8 litre engine) this fan can apparently blow 275cfm at our redline of 6400rpm.
Our engines can flow 252cfm at 6400rpm redline. So that gives an increase of 23cfm at redline.
So. dividing 275 by 252 gives a pressure ratio increase of 1.09 (the engine will breath 1.09 times it's naturally aspirated stock rate).
1.09 * sea level air pressure of 14.7psi will create a boost pressure of 1.323psi.
In simple terms; 1.323 * 174 stock hp will create 190hp.
Keep in mind that this is a centrifugal type blower and boost will not be felt untill later on in the rev range plus some boost will be lost due to pressure losses within the intake then if the cfms stated are anything near what is quoted then you could well be seeing a noticeable increase near redline but at idle and cruise nothing much at all, there may even be a loss due to obstruction in the induction path.
*edit* just noticed quoted cfm figures are for engines of 85% volumetric efficiency, 85% ve is usually quoted for multivalve engines so our 12v 2valve chambers will be usually quoted as having an ev of 80% so again the actual cfms will be lower = lower boost = lower power.
Our engines can flow 252cfm at 6400rpm redline. So that gives an increase of 23cfm at redline.
So. dividing 275 by 252 gives a pressure ratio increase of 1.09 (the engine will breath 1.09 times it's naturally aspirated stock rate).
1.09 * sea level air pressure of 14.7psi will create a boost pressure of 1.323psi.
In simple terms; 1.323 * 174 stock hp will create 190hp.
Keep in mind that this is a centrifugal type blower and boost will not be felt untill later on in the rev range plus some boost will be lost due to pressure losses within the intake then if the cfms stated are anything near what is quoted then you could well be seeing a noticeable increase near redline but at idle and cruise nothing much at all, there may even be a loss due to obstruction in the induction path.
*edit* just noticed quoted cfm figures are for engines of 85% volumetric efficiency, 85% ve is usually quoted for multivalve engines so our 12v 2valve chambers will be usually quoted as having an ev of 80% so again the actual cfms will be lower = lower boost = lower power.
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10-12-2005, 08:02 AM
#10
you mean 12v, but volts are not your concern, it's AMPs !
and I seriously doubt that it can produce 1200 CFM without a heavy drain on the alacrical system.
And the harder your alternator works the more HP is lost to drive it !
And the harder your alternator works the more HP is lost to drive it !