Author Topic: Smá fróðleikur um keppnisbensín  (Read 1887 times)

Offline stefth

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Smá fróðleikur um keppnisbensín
« on: May 28, 2008, 11:43:50 »
Þetta er smá samanburður á Sunoco-bensíninu og því sem SHELL er að selja (TT 114 Racing Fuel frá Chevron Phillips).

Það eru heilmikil vísindi á bak við framleiðslu á þessu en ég held að þau gildi sem skipta okkur mestu máli séu RON- og MON gildin.

RON (Research Octane Number )  virðist vera efnafræðilega útreiknuð Oktan-tala samkvæmt því sem ég hef séð, en MON ( Motor Octane Number) virðist vera raun oktan-tala og skiptir því miklu meira máli.


Auglýsta oktan-talan hjá framleiðendum er því MON+RON deilt með 2.

Chevron Phillips: RON(119)+MON(109) deilt með 2 =  114 oktan

Sunoco Maximal: RON(118)+MON(114) deilt með 2 = 116 oktan


KVEÐJA, STEBBI Þ.




(Tekið af heimasíðu VP Racing fuels)

The four most important properties of racing fuel.

You can't make a racing fuel that has the best of everything, but you can produce one that will give your particular engine the most power. This is why we produce different fuels for different applications. The key to getting the best racing gasoline is not necessarily buying the fuel with the highest octane, but getting one that is best suited for your engine.

1.   OCTANE – This is simply the rating of a fuel’s ability to resist detonation and/or preignition.  Octane is rated in Research Octane Numbers (RON), Motor Octane Numbers (MON), and Pump Octane Numbers (R+M/2).  Pump Octane Numbers are what you see on the yellow decal at the gas stations and represents an average of RON and MON.  VP uses MON because this test method is more relevant to racing.  Most other companies use RON because it is higher, easier to come by, and sounds better in marketing messages.  Don't be fooled by high RON numbers or an average -- MON is the most important for a racing application.  However, the ability of the fuel to resist preignition is more than just a function of octane.

2.   BURNING SPEED - The speed at which fuel releases its energy.  In a high-speed internal combustion engine, there is very little time (real time - not crank rotation) for the fuel to release its energy.  Peak cylinder pressure should occur around 20° ATDC.  If the fuel is still burning after this, it is not contributing to peak cylinder pressure, which is what the rear wheels see.


3.   ENERGY VALUE - An expression of the potential in the fuel.  The energy value is measured in BTUs per pound, not per gallon. The difference is important.  The air:fuel ratio is in weight, not volume. Remember, this is the potential energy value of the fuel.  This difference will show up at any compression ratio or engine speed.


4.   COOLING EFFECT: The cooling effect on fuel is related to the heat of vaporization.  The higher the heat of vaporization, the better its effect on cooling the intake mixture.  This is of some benefit in a four-stroke engine, but can be a big gain in two-stroke engines.    




Offline 1965 Chevy II

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Re: Smá fróðleikur um keppnisbensín
« Reply #1 on: May 28, 2008, 13:04:47 »
Sæll Stebbi,er tunnan frá SHELL á 56þús núna? eða ertu með einhvern díl?´
Ég sá að þú varst að auglýsa eftir meðkaupanda á tunnu á 56k.
.....and 500 pounds of torque......what ever that is.
1.30 60ft 5.78 @ 119.9mph 1/8 - 9.07 @ 148.2 mph N/A Pump gas

Offline stefth

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Re: Smá fróðleikur um keppnisbensín
« Reply #2 on: May 28, 2008, 13:21:29 »
Sæll Frikki,
Já, ég hafði nokkuð fyrir því að fá þetta í gegn.
Kv, Stebbi