VP fuel!

[Mister T]

Re: VP fuel!

How much for a 20 L barrel? Also, would it give me much benefit above and beyond what I'm getting with my water/meth?

[nemohm]

Re: VP fuel!

Race fuel (smell) - 87 + powdered cayenne pepper?

I've read somewhere that higher octane fuels extend the ocurance of carbon buildups - timing by itself can not compensate for unchanged compression ratio (atmospheric engines).
What are your impressions?

[aliencurv]

Re: VP fuel!

Race fuel (smell) - 87 + powdered cayenne pepper?

I've read somewhere that higher octane fuels extend the ocurance of carbon buildups - timing by itself can not compensate for unchanged compression ratio (atmospheric engines).
What are your impressions?

you must mean naturallly asperated engines and static compression ratio.

if your car doesn't have variable cam timing or boost, then you have a static compression ratio. but that's okay because there is still additional power to be had with higher octane fuel. the flame front is slower as the octane increases. so you'll need to tune your ignition timing for the fuel. you won't make a substancial ammount of additional power. using some online calculators you can predict the ammount of potential energy from your engine specifications (displacement, stroke, valve size, valve timing, ignition timing, etc). but those calculators won't take intake and exhaust flow inefficiencies into consideration.

if a vehicle asks for 87 octane, and someone puts in 94 octane.. the vehicle will actually have worse gas milleage and less power. this is because the higher octane fuel burns at a different rate. your computer/tune needs to be programmed for the specific octane.

i laugh everytime i see movies use the words "high octane" to sound explosive. because that means it burns slower ..

[The_Jerbel]

Re: VP fuel!

Actually, higher octane fuels don't burn slower, they just have a higher activation energy before oxidizing, thus the deflagration occurs at a higher energy state. This allow the combustion to release a greater amount of energy when the reaction occurs. Essentially, it takes more heat and pressure to ignite higher octane fuels, but they don't burn any slower than lower octane fuels. If anything, they burn slightly faster since there is more potential energy pushing the reaction, but they certainly aren't any more explosive.

As gasoline is compressed, it's heat energy increases. Low octane gasoline deflagrates at a lower energy point than higher octane gasoline.

I agree that a motor requiring 87 oct will not get as clean a combustion reaction as a high-compression motor that specifies 94 oct, and will therefore get worse gas mileage and less power than if it used 87 oct, simply because the combustion is not as clean, and the oxidation reaction is not completed as efficiently.

[aliencurv]

Re: VP fuel!

Actually, higher octane fuels don't burn slower, they just have a higher activation energy before oxidizing, thus the deflagration occurs at a higher energy state. This allow the combustion to release a greater amount of energy when the reaction occurs. Essentially, it takes more heat and pressure to ignite higher octane fuels, but they don't burn any slower than lower octane fuels. If anything, they burn slightly faster since there is more potential energy pushing the reaction, but they certainly aren't any more explosive.

As gasoline is compressed, it's heat energy increases. Low octane gasoline deflagrates at a lower energy point than higher octane gasoline.

I agree that a motor requiring 87 oct will not get as clean a combustion reaction as a high-compression motor that specifies 94 oct, and will therefore get worse gas mileage and less power than if it used 87 oct, simply because the combustion is not as clean, and the oxidation reaction is not completed as efficiently.

you're right.. and wrong. i didn't expect to get technical.

but firstly, lower octane fuels don't have less energy then higher octane. it's energy potential is determined within the parameters of the application (i.e. in an engine: static/dynamic compression and ignition timing).

in real world fueling examples, the octane is raised with additives. the fuel now takes on some characteristics of the additive (i.e. ethanol). because the mixture inherits it's additive'ss characteristics, one of the effects is slower frame front. ALSO, the precision/predictability of high octane fuel is greater then low octane fuel. which makes aggressive ignition timing safer. and yes, it's activation energy is raised which allows for a higher compression before external ignition.

you should also note that STOICH with 94 octane husky/mohawk is lower then petroluem fuel due to the inheritted features of it's ethanol additive.

in a lab, if petroleum fuel's octane was altered at a molecular level then the flame front would be the same speed as a lower octane fuel. but high octane pump fuel's octane is raised with additives.

also, you don't burn cleaner with high octane fuel.. it merely burns smoother and "controlled" (within the combustion design of the cylinder head specifications); where lower octane fuel is less controllable by the head design.

on that note is a good place to say this. even though ppl turbo a naturally aseperated engine need high octane, it's still not as effecient as it could be for a reason not many ppl think about. the cylinder head design! the cylinder head within the combustion chamber is meant to control and direct the combustion with it's angles. a low octane engine can't control the combustion as much, so the cylinder head design is less detailed.

[The_Jerbel]

Re: VP fuel!

You say that I'm right and wrong, but it looks to me like we are 100% in agreement in our statements. What you have posted does not contradict my comments. I agree completely with your post above, but with a little further explanation.

The only two caveats that I will add are these:

When I said that higher octane fuel deflagrates at a higher energy state than lower octane fuel, I did not mean to infer that higher octane fuels inherently have an larger quantity of chemical energy. What I was implying, is that the mechanical energy of the piston compressing the fuel is transfered into potential energy of the compressed fuel. Therefore, higher octane fuel has the potential to be compressed and "energized" by the engine to a higher degree without detonation, if you will, than low octane fuel. When it is ignited, it consequently releases a greater amount of energy. This is completely logical when you compare the power potential of race gas compared to pump gas.

Secondly, I also did not mean to imply that higher octane fuel naturally burns cleaner. Not at all. What I was trying to describe was actually in support of your comment regarding a vehicle asking for 87 oct fuel, but being fed 94 oct fuel, and the reason why it will get worse fuel economy and make less power. If the tune is not changed when using higher octane fuel, higher octane gas requires more energy to begin burning, and therefore begins combustion at a later point in the compression stroke (after spark has occurred), and does not oxidize as completely during the power stroke as the lower octane fuel that begins sooner. This might leave a slight amount of unburnt fuel residue that exits in the exhaust, depending on the actual octane of the fuel, design of the engine, and the tune itself. If you modify the tune from the 87 oct map to the 94 oct map, you can more efficiently make use of the chemical properties of the higher octane fuel.

Good discussion

[The_Jerbel]

Re: VP fuel!

You see, I knew that all those organic chemistry courses in university would come in handy somehow haha

The only thing remotely interesting about organic chemistry is how it applies to the synthesis of hydrocarbons, and how they undergo chemical reactions (specifically, oxidization).

[DubSport]

Re: VP fuel!

OK braniacs lets get us some race gas! So we can go faster, and... stuff. yeah. they're smarter than me.

[aliencurv]

Re: VP fuel!

man it's good to be on a forum with good ppl

i have still have a 20 litre jug sitting in my basement. but ... i've been thinking of buying a barrel.

[R-Audi]

Re: VP fuel!

I havent bought race gas in two years.. I think a tin of VP109 was $120 and the barrel was $500 or so?

[Mantis]

Re: VP fuel!

Last time I picked up MS 109 it ran me less than a hundy, Let's see a list of those interested, I will contact Jordan and see what he can do for us. I think if we have more than 10 interested we can get a great deal. I have several empty tins that we could barrel fill if we went that route.

1. nothing77

[R-Audi]

Re: VP fuel!

1. Nothing77
2. R-Audi (Barrel or tins)

[aliencurv]

Re: VP fuel!

I also have a few 20 litre tins. so if we go the barrel route, i'm okay with filling a few up. i have heard that if you expose race fuel to air (open the lid), then it only lasts a month or two. that's why i never bought a barrel, because i don't know how quickly i'd use it.

1. Nothing77
2. R-Audi (Barrel or tins)
3. AlienCurv (tins)

[R-Audi]

Re: VP fuel!

Didnt think about that... I was just offered a barrel pump tap and thought it woul dbe fine. Maybe tins is better...

[nemohm]

Re: VP fuel!

I could only hope nobody piles his fuel stocks around Crowfoot area!