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Jetdat

By Jetdat,
in Victoria

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2rismo Grand Master

2rismo

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Obviously their not the same but are the same octane rating. He doesn't run avgas in it at the moment so there is no need to run it and their not really completely separate animals.

They might be the same octane rating but they don't share the same octane numbers. Apart from different burn rates, and the fact that Avgas contains TEL, the differences are vast. I again refer to MoTeC's testing on an engine dyno which suggests that V-Power Racing performed better than Avgas in every situation. The fact that the engine used was a 4G63 from an EVO IX only strengthens the argument that what they found applies to Skyline motors.

They ARE completely different products.

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Rowdyr32 Mentor

Rowdyr32

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2rismo after all this you are confirming what I said in the first place. I'm in this for a discussion/learn.

The mixture known as gasoline, when used in high compression internal combustion engines, has a tendency to ignite early (pre-ignition or detonation) causing a damaging "engine knocking" (also called "pinging" or "pinking") noise. The discovery that lead additives modified this behavior led to the widespread adoption of the practice in the 1920s and therefore more powerful higher compression engines. The most popular additive was tetra-ethyl lead.

Lead is also a good lubricant for valves which prolongs engine life and the avgas around now is 100ll which is low lead with anti knock additives added.

Avgas also burns slower due to if having to stay as a liquid at high altitudes.

I couldn't find their BTU ratings though.

This might have a little to do with it.

It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion). However, premium grades of petrol often contain more energy per litre due to the composition of the fuel as well as increased octane.

What is the go with the octane rating vs octane number I don't know.

Marine diesel or Jet A-1 could be better :(

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Omurru Veteran

Omurru

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thats what i thought too that one tankful wouldnt hurt..

anymore info on toulene mix.. where to buy, how much to mix, how much cost and how much does it boost the octane??

might do some search on toulene..

There's a thread in the performance section I think called "backyard race fuel" I got the link somewhere if you can't find it, but losta interesting stuff in it.

AVgas will also melt your CAT causing it to block up. Yes...in one tank. Much like leaded(super) petrol would do if you ran it.

lol...cat... :(

Marine diesel or Jet A-1 could be better :)

lol, have fun running diesel in a petrol engine and A1 is Kero so have fun running that too :) A1 does smell good though..... :P

I think half the joy of running avgas is the smell :( I'd never put it in my skyline but a friend usees it in his SS all the time :P

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Rowdyr32 Mentor

Rowdyr32

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I found this in Wikipedia as well.

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, AvGas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116). Typical "octane booster" additives include tetra-ethyl lead and toluene. Tetra-ethyl lead is easily decomposed to its component radicals, which react with the radicals from the fuel and oxygen that would start the combustion, thereby delaying ignition. This is why leaded gasoline has a higher octane rating than unleaded.

Don't hang me on the BTU rating but:

You stated that Avgas made less power why is this? I need facts.

As for Toluene I found it has a octane rating of 114. I have 20 litres at work and I know Snowy was put it in his car a while ago. Its commonly used as a knock deterent as far as I know.

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Jetdat Veteran

Jetdat

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my only reason for wanting to run higher octane was to reduce any chance of pinging...

i rarely have spirited runs let alone many runs in a row all day like in a drag day situation. so although i trust Benno's tune it still is unknown how the engine might behave on the track simply because its never been on one..

power increase was never my intention although i must admit R31Nismoids reply did make me think about fattening the power curve with better fuel..

but after reading the discussion and some good points made i decided to run on v-racing and see how it goes.. definately learned few things from this thread.. thanks for the replies...

thanks also for the links which i will be checking out...

edit: http://www.motec.com.au/fueltest/index.htm

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Jetdat Veteran

Jetdat

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There's a thread in the performance section I think called "backyard race fuel" I got the link somewhere if you can't find it, but losta interesting stuff in it.

yeah i found it last night and read thru most of it, was good reading..

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Jetdat Veteran

Jetdat

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Octane isn't the only measure of a fuel when you're after some protection for a track day. Some of the very high octane unleaded fuels will burn very rapidly compared to pump fuel and could result in a lean AFR. Motec's website has some very interesting fuel test data comparing avgas and v-power racing from shell.

had a look at the motec site, very interesting indeed..

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Jetdat Veteran

Jetdat

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Jetdat

If benno has set your tune with V power racing then don't touch it and race it with that fuel in the tank.

It will be fine.

I ran my car around sandown with his tune on vpower racing and the knock levels were fine all day.

Your engine has been tuned with the fuel characteristics of v power racing, don't go putting a higher octane rating fuel (even if it is unleaded) as this fuel will exhibit different burn characteristics etc

point taken archie01.

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Bass Junky Grand Master

Bass Junky

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Jetdat.

If Benno tuned your car in V-Power Racing, DON'T use anything other than V-Power Racing.

You wont need to change anything. It's not like you are blazing away for 10-15 minutes on full boost, you are only blazing for maybe 10-15 seconds :O

If you are really worried, I can add some fuel to your tune temporarily on the weekend. It's not a permanent setting, it's a very basic add of fuel.

But, yeah, if Benno tuned it, it will be fine.

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