Race gas DIY thread.

DIY/TECH/INFORMATIVE
#1

Here is everything you never wanted to know about making your own “race gas” at home.

I spoke a few weeks ago on making your own ‘race gas’. I don’t want to bog down the post with to many technical points or to many figures that might make for a difficult read. This will just be a general overview, This should help you understand better what your options are and what is needed to change the formulation of your gas.


Why would I want to buy or make race gas?

When we buy race gas we are generally buying a fuel that has a much higher Octane and power rating then pump gas. This gas is specifically formulated for racing and motorsports. Higher octane fuels and race gas, helps in making more power in high hp motors. If you’re racing on a hot day race gas can also help keep the car safer then standard pump gas. Race gas in general offers a larger amount of power and safety in higher hp cars

If you can’t or don’t have a local race gas option how can you make your own “race gas” at home?

One way is to mix in better fuel to your pump gas to raise the octane and power rating. We call this fuel blending. However we need to know that race gas starts with a better grade of fuel stock as a base. The base fuel stock used for race gas and the base fuel stock used for pump gas are very far apart in terms of quality and what is in them. So, at the start, pump gas is already at a disadvantage, pump gas has fillers and other chemical components added to meet EPA standards for use on public roads. Many of these fillers or components don’t help us in our pursuit of power from pump gas. Many of the EPA mandated additives can lower the octane level

What is octane?

Octane itself, isn’t gasoline but a component of gasoline. The component Octane, is a chemical formula with dydrocarbon and alkane. There are many different chemicals structures (Isomers) that can be formulated from Octane that are used in helping raise its function in gas. The octane rating in gas can be raised by things then Octane or a byproduct of the chemical octane. There are components of gasoline and other chemicals that can also contribute to increasing the octane rating.

Let’s start with standard fuel you get at the pump and some of the additives.

There are winter blends and summer blends. Most fuels have a good amount of additives, over 200 in total to help with a wide range of things. Here are the basic ones.

Detergents - Get added to the fuel to help reduce carbon, deposits and other buildup associated with fuel burn, helps keep spark plugs clean

Stabilizing agents- help stop fuel break down or gum deposits, prevent icing, improve stability, vaporization and lubrication

Octane additives or antiknock additives – These are the ones we want to improve on for better performance from our gas. Generally, the chemicals used to help the power output, octane rating and antiknock properties of gasoline are classified as hazardous substances and are regulated only allowing for a specific amount used in distributed to public gasoline. This is why some states with high emissions standard have lower octane options at the pump

How do you know what octane you’re starting with and pumping into your car?

When you look at the pump and you see numbers located with options for 89-91 or if you’re located in an area that has it 92-93, these numbers represent the octane rating of the fuel. Without getting into a long explanation of RON and MON, we are just going to go off pump numbers you would see in America.

For the below examples, we are going to assume we are always using a base of 91 pump octane. Let’s keep in mind that 91 California and 91 New Jersey might have different additives to help pass local emission rules and regulations thus making one less ‘danger resistant’

What can we do to make our 91 more like 101?

The safest and easiest way is called “fuel blending”. This is when you take two fuels and blend them together to make one more desired blend of fuel. The two easiest fuels to add are Toluene and Xylene, Ethanol, or Ethanol as E85. The good thing about these is they are actually used as fuels and not just chemicals. Toluene has been used as a standalone fuel for years in F1 and other competitive race situations and Ethanol or E85, we all know that is readily available at the pump in most states.

What is the difference between the two options?

Toluene and Xylene are in the Aromatic class of chemicals. This class comes from petroleum, has no metallic or oxygen content, and doing so means little or no concern for 02 sensors and other emission system components. Aromatic chemicals come with a high energy content and are very stable ‘sensitivity’ grade wise. Being less sensitive means the fuel performs well under great stress and load. Aromatic chemicals are already used to help octane in both pump gas and race gas.

Ethanol, Methanol or MTBE are in the Oxygenates class of chemicals. While Oxygenates have less energy content and are less stable than the Aromatic class, they do carry oxygen-bearing compounds with them; thus raising the oxygen content of the gas helping to make for a more complete burn, while also doing a great job at removing large amounts of heat. The cooling properties alone have people spraying certain Oxgenates into their intake tracks to cool down incoming air.

Well, if I can just go get E85 out of the pump, why don’t I just use that alone or just use that to fuel blend?

What generally gets over looked when people talk about fuel blending or strictly using E85 is the actual power output of E85 or Ethanol. Lots of people rave about E85 but don’t understand that E85 has LESS actual power output then standard fuel. The difference in octane can be great but you actually are getting a lower energy content.

Let me explain.

MJ/KG = mega joules per kilogram and BTU/GAL= British Thermal Unit. These are basic outputs of power. When you see the MJ/KG or BTU/GAL that is the amount of power released per GAL or per KG. The higher the numbers the more power unit.

Conventional gas. MJ/KG = 44.4 ____ Net BTU/GAL= 115,000 OCT = 92
Ethanol MJ/kG=26.8_____Net BTU/GAL= 75,000 = OCT= 111
Ethanol E85 MJ/kG=26.8_____Net BTU/GAL= 82,000 = OCT= 108 * Some SAE tests show lower OCT figures.
Toluene MJ/KG=43.1____Net BTU/GAL=114,000= OCT= 114

Ethanol has a high oct and oxygenate level but a lower chemical energy content. The standard pump gas in some areas include 10% Ethanol. People have been reporting that they feel a loss of power or performance using gas that includes Ethanol. Here is how the numbers stack up when adding Ethanol to gas.

Conventional gas_Net BTU/GAL= 115,000 OCT = 92
Conventional gas with 10% Ethanol_Net BTU/GAL= 111,000 OCT = 92

Since Toluene and Ethanol already come in standard pump gas and Toluene has a higher energy content and octane rating. I will use Toluene in our mixing calculations below. Ethanol is great for use as a octane, oxygenates and coolant agent and Toluene is great for a octane, power and stability agent.

Toluene= more power
Ethanol = more cooling.

Mixing - how do you calculate what your end octane level is?

It looks something like this and can be used with any fuel you choose to mix with pump gas.

(gal of reg gas * octane) + (gal of added fuel * octane) / total gal = end octane.

For example:

You have 3 gallons of 91 and you add 1 gal of Toluene@ 114. The math would look like this.

(3 x 91) + (1 x 114) / total gal = end octane
3 x 91 = 273
1 x114= 114
273+114 = 387 / 4 (total gal) = 96.75

To bring up the octane value 5.75 points we needed to add 25% Toluene. If you wanted to achieve a total octane of 100 you would need to add 40% Toluene.

The math looks like this:

(3 x91)+(2 x114)/ total gal=
3 x91=273
2 x114=228
273+228=501 / 5 (total gal)= 100.2

This method of mixing fuel compounds (Toluene or E85) will almost always require a 30% mix before you’re going to see enough of the fuel blending to make an impact. While you might be able to bump the octane number a few points using less then a 30% mix the function of the Antiknock properties take a larger amount (over 30% mixed) to make a real impact.

Now that I know all this, how to I go about mixing and doing so safely?

Here is what I do, I went and bought a 5 gal plastic fuel container. I bought a blue one, I believe blue is recommended for diesel or kerosene. This way, I won’t accidentally fill my lawnmower with 101 octane. I fill the container with just under 3 gal of standard pump 91. I keep it just under 3 gal of 91, because I’m keeping in mind that when I add the fuel mix to the tank there will still be a little fuel left in the tank. Then I add 2 gal of Toluene, bam I have just over a 100 octane mix. From there I drive till I get my zero miles to empty and I poor in the 5gal of fuel.

RS5 and E85 official thread
c6 s6 e85
#2

The next question that always follows fuel blending is chemical blending. “octane boosters”

Do “octane boosters” work?

The above method of fuel blending, taking two fuel compounds together to raise the octane, antiknock and power increase per unit. Fuel blending is one easy way to raise the performance and octane properties of pump gas. Another option to raise the octane levels, are to use chemical octane boosters. While there are dozens of additives you can choose from, there are a few that work great. When looking at what additive to use, its’ best to look at availability and long term use effects of using chemical boosting other then fuel blending.

The old “octane boosters” that we have seen in the past, were just repackaged Toluene or Ethanol. Due to a few changes in the laws over the years “octane boosters” now have a little bigger of a punch as there are a few chemicals that actually work that are now available.

I’ll just talk about two “octane boosters” as they have been used successfully for years and are still being used today.

Iso Alkanes - Are a combination of Alkanes that are very helpful in octane level increase and are major components in conventional jetfuels

MMT - Methylcyclopentadienyl Manganese Tricarbonyl. MMT is a very VERY potent chemical that is used today to bring up fuel octane while remaining very high in power output per unit. The big daddy of all race gas blends is lead or Tetraethyllead (TEL) MMT is used to replace lead. Metallic compounds like MMT and TEL are very effective in all ranges of gas improvement. The only issue is TEL will destroy your 02 sensors after about 1 or 2 uses. MMT if used in the right amounts won’t.

Here are two known “octane boosters” Both of these are used in race gas, in most configurations.

The first one is almost straight MMT, Its offered from a company called race-gas.com. MMT is something that works great and not something you can just pick up at your local home depot.

The second one is from torco. Torco actually has a good line of chemicals and race gas options. This “octane booster” is Torco’s Race fuel accelerator and is a mix of Iso Alkanes, MMT, Toluene and Xylene

First one

http://race-gas.com/_uploads/callouts/_source/morespeedcan.jpg

There was a link to a new product people were asking about. Called “race-gas” it is race gas concentrate. Race fuel concentrate is 100% MMT.

Then this one from Torco

http://torcoracefuel.net/1-pix-torco/Accelerator-bottles.jpg

Torco Race fuel accelerator is a mix of Iso Alkanes, MMT, Toluene and Xylene

Do these products do what they say?

Yes, kind of

They are both powerful chemicals or chemical metallic compounds on their own. They do work but they both have diminished returns if you use too much. MMT will leave behind byproducts and deposits especially if you get too greedy in trying to use it. The Torco offering is less likely to leave deposits but the same is true, if you use too much you will find deposits building up.

Most off the shelf “octane boosters” contain MMT. I would make sure you read the label before you add anything to your tank. Even still, if you’re going to add a “octane booster” I have found the best results come from mixing outside of the gas tank rather then in it.

The concerns are mixing chemicals that have a different density then the gas your adding to. Mixing chemical “octane boosters” in a separate container tend to yield better results of homogenization.

#3

I have more to add, I just got tired of typing.

#4

CV, Awesome post and thanks for sharing the knowledge… Looking forward to anything else you may add… The octane boosters you mention what kind of ratios can we expect with them given they are usually used in a smaller amount per gallon so to say… It’s been a while since I’ve used one but I belive it was like 32 oz per 10 gallons? Can that really raise the octane to 100-105?

Have you tried the new Gulf Mach 116 race fuel? Any thoughts or comparisons to the Shell URT?

Thanks again for the awesome post!

#5

This is very very good info. One question which I’m sure you will answer is when all is said and done which one actually comes out to be more cost effective?

#6

Great post!

I have a bit to say about MMT, since I’ve torn down a couple motors that ran life with 2-300,000 km of MMT-laden gas. I could have shown you at the time manganese deposits on the valves that were strong enough to bust the valves, let alone plug the cats and foul the O2 sensors. I would skip it unless you want it for occasional use.

I would have had no idea what MMT was at the time, but I had two chemist friends who worked for the government at the time and used to verify the additives and blends used by the gas stations. One positively identified manganese on the B-series valves that I had that had failed. FWIW the two guys I knew said to stick with Shell for the additives package they use, 100% no MMT. This is going back over 10 years ago though.

#7

what are B-series valves?

#8

Honda motor possibly

#9

Yup, honda. Even with all that crap on the valves, B-series heads flow amazingly well.

From what I remember, canada generally got MMT spiked gas while the US banned it. Only Shell and Sunoco 94 were MMT free up here for many years until recently. The auto manufacturers were getting upset once OBDII came in and people were getting catalyst and O2 sensor failures from MMT and blaming it on the manufacturers.

Anyway I didn’t want to get too far off track. That sums up my experience with MMT

#10

I appreciate the kind words everyone thanks.

If I remember correctly Gulf is part of shell? They share some of the same stock blends?

I will make a new post to just address your other question.

#11

Metallic compounds like MMT for example, are nasty but they work and they work very well. They work so well you don’t need very much, too much and jspazz already gave a good first hand account of what will happen.

The big thing I think people need to remember is MMT and boosters like MMT are not fuels, they’re additives. A good rule of thumb is, the more effective the metallic compounds are the less you will need to impact octane. With that, the more effective the compound is the more deposits they will leave behind when burnt. You don’t need to add very much say, MMT to fuel to see an increase on the octane. Adding less then 1fl oz (.8 to be exact) to 1 gal of 91 octane will raise the 91 to almost 94.

The best results are not from in tank filling. Best results will be from mixing in a separate container.