Fuel test - what will pass?

[DavidM]

..which is a problem I have with "track gas" at NHIS.. I forgot my gas can at home this past weekend and I figured that I would be able to buy some fuel at the track. I was expecting to pay through the nose for "regular" fuel, but all they were pumping last weekend was 112 octane leaded! Since I didn't know if the systems in my production-based, OBDII-electronics IT car would take kindly to leaded fuels, I passed and was fortunately able to "borrow" a couple of gallons of pump fuel from a friend.. If we're required to buy fuel at the track, can the track be required to sell us stuff that works in our cars?

-noam
[/b]

I asked this in a previous thread. The short answer is that you can run leaded gas if you've got all the emissions stuff removed (mainly the catalytic converter I believe). There was some belief that it may shorten the life of the O2 sensor, but that shouldn't be a big issue unless you're running 24 hour enduros all the time.

Most of the tracks I go to seem to have 100 unleaded and 110 leaded for the same price. I've run the 110 without any issues in my car. My motor is a max build and it gets hot here in Atlanta. I'm not willing to risk the motor with just 93 gas.

David

[x-ring]

OK, a few random observations this weekend at the fuel table.

91 octane pump gas from Albuquerque, New Mexico (no ethanol or MTBE): DC = 2.0

91 octane pump gas from Pueblo, Colorado: DC = 3.2

100 LL avgas from a competitor: DC = -0.1

The reagent test chemicals had been left in the equipment trailer and, according to the fuel princess, didn't look right. For that reason we suspended reagent testing for the weekend, so I have no data on that. She tells me that MTBE blended pump gas will usually fail one reagent test (I don't remember now which one). Ethanol blended fuel will usually fail the DC test.

The young lady working at the counter at the Phillips 66 on highway 50 early Sunday morning in Pueblo couldn't tell me what, if anything, was in their fuel besides gasoline. The pump sticker indicated that the fuel 'may contain polution reducing additives'. Wonderful.

I didn’t think to ask the guy who brought in the 100LL avgas where he got it.

The track fuel vendor brought us a sample of fuel that had been left out in the sun for a couple of hours in a translucent white, closed, container. I think he said it was VP104 leaded. Anyway, it had changed from its normal bright blue color to dark grey. The sample fresh from the pump (drum?) was DC = 0.0. The now grey sample he brought was DC = 10+, which wouldn’t pass for most other classes. Two morals to that story are ‘Don’t use your fuel jugs to hold down your canopy’, and ‘Use opaque fuel jugs.’

Tech may have tested the fuel available at the track. They may or may not post the results, but they should tell you, if you ask.

[Bill Miller]

Ty,

You raise an interesting issue about fuel that will pass when it's "fresh", but may break down w/ time, exposure to light or air, etc. and no longer pass. I used to buy my fuel by the drum, and take what I needed to the track (I got a great deal on Sunoco 114 Purple if I bought 2 drums at a time).

[Eric Parham]

This is a very troubling issue. It's not even the performance advantage that I care about, but I sure wouldn't want to get cancer or brain damage (read: more) from breathing some slime-ball's exhaust at the track. It is well-known that some additives can improve lap times by significant amounts (e.g., 1 second). I know some have tried nitromethane, and reported significant improvements even in an IT engine. I've heard that some of the harder to detect additives may be much more hazardous to our health. If the inexpensive tests aren't good enough to separate the extremely toxic from the straight gasoline (or ethanol, which is even less toxic), then my vote would be to spring for the really expensive equipment and shuttle it around as much as possible. Also, perhaps the club should make it known which additives should REALLY be avoided for health reasons, so at least the users will steer towards the less dangerous ones for their own health and hopefully that of the racing community. Ignorance may be bliss for the user, but it's certainly not for the rest of the pack/workers/etc. Although it sounds like a cheap solution (and one that I'd actually buy into after I was done grumping), forcing the use of any track's fuel is unworkable since there's always going to be fuel left over from the last track in our cars.

[x-ring]

Bill -

I wish I could say if the change was due to light or heat, or both. It was pretty warm at Pueblo this weekend (100+ in the shade). Someone told me that the workers (including the tech crew!) drank something like 60 cases of water over the weekend. We probably used 1000 pounds of ice, too.

Eric -

I wish I knew more about this. My background is mechanical engineering, not chemistry, but I'm learning. I agree 100% about the additives. Have you ever been 'downwind' of a nitro dragster? The headache will last for hours, as you probably know. I, too, wish we had more sophisticated testing equipment to separate the toxic from the hazardous. Hazardous I can deal with; toxic I'd sooner stay away from. I'm told, probably accurately, that the inexpensive (~$750) testing equipment we have now will reject all known fuel adulterants. The problem is that it will also reject common air quality additives. More sophisticated equipment can differentiate between the two. The problems with that are that the cost increases several orders of magnitude, probably into six figures, the equipment probably wouldn't be able to be used by the current tech volunteers, and the equipment can't be used in the field. One solution would be to draw samples at impound and then send them to Topeka for testing. Then we get into the degradation problem (would the characteristics of the fuel when tested be the same as when it was drawn). I'd also imagine that FedEx would want a small fortune to ship 50 or 100 small bottles of gasoline across the country, which would have to be paid for by, you guessed it, the drivers.

OK, since it clear that I've about exhausted my knowledge on this subject, how about if we come up with a list of questions for the fuel experts. I'll probably have time, at the RubOffs, to chat at length with the fuel experts Dave Badger and Chemical Ira (when I'm not up to my elbows in SM bits) and get the definitive answers to those questions. If I speak to either of them sooner I'll post answers.

Well, what are your questions?

[RSTPerformance]

Well, what are your questions?
[/b]

How can we ensure that ANY gas that we can buy at the pumps will be legal? I am 100% against race fuel being used in an IT, SS, Touring, or SM/SSM car. The engines are NOT built up so much that you need or gain anything major from race gas. This is Club racing (even Nationals are club level) and the costs NEED to be maintained to make it affordable to those such as myself who can't even afford it.

Raymond

PS: Don't bother me with data showing that "Race Gas" gives you 5hp and you need that to win, I am not interested in that end of the spectrum (It should be your/our choice to by overpriced gas). I am only interested to know that I can go to ANY legit gas station on the street and get legal gas and still beat you.

[Bill Miller]

How can we ensure that ANY gas that we can buy at the pumps will be legal? I am 100% against race fuel being used in an IT, SS, Touring, or SM/SSM car. The engines are NOT built up so much that you need or gain anything major from race gas. This is Club racing (even Nationals are club level) and the costs NEED to be maintained to make it affordable to those such as myself who can't even afford it.

Raymond

PS: Don't bother me with data showing that "Race Gas" gives you 5hp and you need that to win, I am not interested in that end of the spectrum (It should be your/our choice to by overpriced gas). I am only interested to know that I can go to ANY legit gas station on the street and get legal gas and still beat you.
[/b]

That's the problem Raymond, you can't just buy pump gas at the local (your favorite station here) and think that it will pass. Ask Joel Lipperini about that one!

Here's a flip-side for you. Why can't limited-prep Prod cars run pump gas? If we can test for legal race gas, and we can test for legal pump gas, why can't you run what you want?

[RSTPerformance]

That's the problem Raymond, you can't just buy pump gas at the local (your favorite station here) and think that it will pass. Ask Joel Lipperini about that one!

Here's a flip-side for you. Why can't limited-prep Prod cars run pump gas? If we can test for legal race gas, and we can test for legal pump gas, why can't you run what you want?
[/b]

Bill-

Agreed 100% In ALL classes you should be able to run pump gas from your local gas station.

If you can't run pump gas then the "safety" reasoning behind the rule is BS. Pump gas is probably the safest thing for us and the rest of the world, otherwise EPA would be all over the industry more than it already is. If anything I say lets ban the race gas in all classes with exception to having it an option in Production, GT, AS and whatever open wheel cars need it.

Raymond

[DavidM]

Bill-

Agreed 100% In ALL classes you should be able to run pump gas from your local gas station.

If you can't run pump gas then the "safety" reasoning behind the rule is BS. Pump gas is probably the safest thing for us and the rest of the world, otherwise EPA would be all over the industry more than it already is. If anything I say lets ban the race gas in all classes with exception to having it an option in Production, GT, AS and whatever open wheel cars need it.

Raymond
[/b]

Just because you don't run race gas doesn't mean you should dictate what other people can do. I run 100 octane as a safety measure. Bob said the only time he ran 93 octane he blew the motor. Coincidence, maybe. I'm not willing to risk a $6k motor to find out, though.

Let people run the gas they want. If you can get by with 89 like the rotary guys, great. If you want to run race gas, fine. Since there's no performance advantage what difference does it make? According to you, those of us using race gas are just throwing our money away. Maybe we are, but I want the right to be able to do so.

David

[RSTPerformance]

Just because you don't run race gas doesn't mean you should dictate what other people can do. I run 100 octane as a safety measure. Bob said the only time he ran 93 octane he blew the motor. Coincidence, maybe. I'm not willing to risk a $6k motor to find out, though.

Let people run the gas they want. If you can get by with 89 like the rotary guys, great. If you want to run race gas, fine. Since there's no performance advantage what difference does it make? According to you, those of us using race gas are just throwing our money away. Maybe we are, but I want the right to be able to do so.

David
[/b]

David-

I am fine with you and others using race gas, I am trying to prove a point that it is very important that we all should be able to use pump gas from our local (lagit) gas station. My point was that IMO if we had to choose between one or another then it should be pump gas not race gas.

Whether or not you need race gas is a whole different conversation that I have no interest in debating.

Those who want to use it that is fine by me, but we should not have to use it.

Raymond

[Z3_GoCar]

David-

I am fine with you and others using race gas, I am trying to prove a point that it is very important that we all should be able to use pump gas from our local (lagit) gas station. My point was that IMO if we had to choose between one or another then it should be pump gas not race gas.

Whether or not you need race gas is a whole different conversation that I have no interest in debating.

Those who want to use it that is fine by me, but we should not have to use it.

Raymond
[/b]

Hey Raymond,

Hot dry air, 110F and ~10% rh, such as we have out here places a premium on octane rating, combined with the fact that all anyone can purchase from the pump is 91. So mandating pump gas just isn't feasable all across the nation. Besides, one burns much more getting to and from the track than on the track.

James

[Bill Miller]

Raymond,

If you're not opposed to people making their own choices as to what fuel they run, don't make statements like

I am 100% against race fuel being used in an IT, SS, Touring, or SM/SSM car. [/b]

[RSTPerformance]

Raymond,

If you're not opposed to people making their own choices as to what fuel they run, don't make statements like
[/b]

I shall fix my quote... 100% against a requirement that we have to use them... on me... sorry

Raymond "rethinking all my posts to be more clear" Blethen

[x-ring]

That's the problem Raymond, you can't just buy pump gas at the local (your favorite station here) and think that it will pass.
[/b]

100% true. Tech will, at least here, check fuel for you if you request it, and give you the results. We don't mind, really.

If we can test for legal race gas, and we can test for legal pump gas, why can't you run what you want?
[/b]

The same pump gas can be compliant or non-compliant depending on what test standard you refer to. The pump 91 I tested this weekend was compliant to IT specifications, but not prod or formula car specifications. I've seen it tested before, though, that it didn't pass even the IT spec. It generally depends on what has been added to it. We can only test for the presence of additives. We have no way of telling what those additives might be, with the gear (dictated by the rules) that we have now.

Imagine for a moment that the rule was 'no toxic aggressive oxygen bearing compounds allowed', which is how I think it should be, all outside considerations aside. A competitor brings a sample for testing, it pops a positive on one of the reagent tests. The competitor says he drives a LP/FP Miata, and he's running pump gas from the store down on the corner. We have no way to tell, using the tests available to us, if the fuel really is from the 7-11 or if it's been juiced with something toxic. The rules we have now err on the side of caution.

Here's a flip-side for you. Why can't limited-prep Prod cars run pump gas?
[/b]

Some can, assuming that by 'pump gas' you mean IT legal gas. Check the notes for the Lotus/Caterham 7 America. So why not all?

[Z3_GoCar]

OK, a few random observations this weekend at the fuel table.

91 octane pump gas from Albuquerque, New Mexico (no ethanol or MTBE): DC = 2.0

91 octane pump gas from Pueblo, Colorado: DC = 3.2

100 LL avgas from a competitor: DC = -0.1

.....

I didn’t think to ask the guy who brought in the 100LL avgas where he got it.

.....
[/b]

BTW Ty,

Thanks for testing the AVgas. I assume the DC is the dielectric constant?

James

[gprodracer]

OK,

A comment from the "I stayed at a Holiday Inn" sort of guy. I have always heard that leaded gas was better for older motors from the pre-catalytic converter days because the lead somehow helped preserve the valves, valve guides etc. I don't know how the unleaded based motors overcame this. I fully agree that we should be able to run either one based on how which we "believe" our motors run best on. I fully believe that my 25 year old pushrod, carburated IT motor ran much better, with less valvetrain noise, using 103 octane leaded fuel. I don't know anything about the chemistry, combustion, physics, or mechanics of why I have had better luck with race fuel. I just know my motor "felt" like it ran better. I also know that I may be full of crap. Bottom line, we need to come up w/ a more comprehensive way of testing that is fair to all.

On the performance enhancing additives (I.E. proplyene oxide etc..I live near the Kennedy Space Center) unfortunately the type of people that would use crap like that probably don't give a damn about it's cancer causing effects..either on themselves, or those around them. It's sad, but likely true, and we need to find a way to eliminate that hazard on a permanant basis, as my eyebrows burn off after following them.
I must admit that it is less of a problem now than it was a few years ago.

Thanks to all who are testing, and providing usefull information about this. We all don't want to keep doing what we think is legal, and being penalized by faulty testing methods.

Mark P. Larson
CFR #164010

[Eric Parham]

Okay, if I understand this correctly, the current test tests for any additives rather than just oxygen-bearing additives, right? Both pump gas and race gas may have various additives that fail the test. The pump gas may also have a small amount of harmful (e.g., MTBE) or harmless (e.g., ethanol) oxygen-bearing additives added in order to slightly lean the mixture and "improve" emissions (among other reasons -- think profit margin, etc.). In such cases, the oxygen-bearing additives cannot have too much of an effect or else the gas companies would get sued for wrecking engines due to excessive lean (figure cars on the street can tolerate no more than 5% "oxygenation" or added oxygen for a stochiometric mix, just as an initial guess). The race gas, on the other hand, might actually have oxygenates added to improve performance, but I doubt that the percentage would be much above that found in street gas since race fuel system controls, in many cases, may actually be less sophisticated than street cars.

Now, the problem comes in when racers, looking for more power, add more oxygenates to their fuel, especially where the added oxygenates produce toxic exhaust. Some may not realize the invisible hazard they are creating, and a few others might not even care (but I doubt it, at least at the club racing level). Does the expensive equipment (that we don't have yet) just test for oxygenates, or does it give a true component analysis of the fuel substances? Is it really necessary to test for everything?

Perhaps an easier test is possible, especially once we realize that we really don't need to check for everything *anyone* COULD add to the fuel, but just what *a racer* WOULD add to the fuel. In fact, IMHO, we don't even need to test for particular additives, but just for a particular result. That result is fuel that supplies more than a reasonable amount (to be defined based on standard available fuels) of its own oxygen (or equivalent for combustion purposes, but I've forgotten too much of my high-school chemistry). Perhaps a test can be devised to see if the fuel actually combusts without enough added oxygen, and simply conclude that it's been doctored-up if it does. Maybe something along the lines of a single-cylinder test engine with accurately metered oxygen supply would do the trick. Or, maybe just putting it in a balloon, submerging that in a tank of water, and trying to make it go "boom" would do the trick Or, what about just feeding the fuel to a standard test engine on a dyno -- would that be close enough? I honestly don't know, but I think one of these types of tests could be used to detect any "doctored" fuel sufficiently for our purposes (i.e., too much oxygenation) at a relatively low cost (e.g., significantly less than "6 figures").

Too bad there isn't a non-toxic and inexpensive oxygen-bearing additive that everyone could use to their hearts' content. At least that would eliminate the toxicity problem, and could even put everyone on a relatively level playing field. Does unlimited ethanol percentage qualify, or would some folks still find motivation to poison us all at the track? The above are just my ideas for thought, and questions for those who know more (whether or not the questions are followed by question marks).

[Bill Miller]

Ty,

I'm a bit confused by pump gas being legal by one test and not others, but not surprised.

And the fact that you mentioned the Caterham goes to the heart of my question. If they can test the fuel in a Caterham for compliance, and that fuel is regular pump gas, why can't they test for that in every Prod car? There's no reason to run 114 octane race gas in a 10.5:1 or 11:1 motor. The Prod RX7 crowd get to run pump gas pre-mixed w/ oil.

Should be pretty easy to figure out what you're running. You essentially declare your fuel. Either you're running race gas or you're running pump gas.

[Eric Parham]

Mark, the lead in the fuel acts as a lubricant as well as for anti-knock. Thus, engines (heads) designed for leaded fuel didn't require hardened steel valve seats or silicon-bronze valve guides, IIRC. Running unleaded in these can cause very rapid wear or pitting of the non-hardened or integral valve seats (confirmed from experience, poor old MG) and probably of the old-style soft cast iron valve guides (I think VW had a problem with this in the mid 70s to early 80s, which is why most of the heads from that era had to be rebuilt/exchanged by VW). A solution for a street car would be to install hardened steel valve seat inserts and silicon-bronze valve guides, but that might not be allowable per various class rules, especially where the original seats were integral to the head material.

[x-ring]

James

Correct, DC is dielectric constant.

No problem on the avgas. A racer brought some by for testing; I remembered you wanted to know, so I made a note. I wish I'd asked him what brand of avgas it was, or at least where he got it, but I was doing something else at the time and didn't think of it until he was gone.

Keep in mind that out reagent test chemicals were suspect that weekend, so we didn't use them. That sample of avgas or either of the street fuels may have failed one or both of the reagent tests.

If any of you guys are going to be at the Runoffs, and want to check a particular fuel, bring it by the tech building and look me up (when I don't have a batch of miatas torn apart) and I'll introduce you the folks at fuel test central. Best if you do it early in the week, once qualifying starts they get pretty busy.

Bill

Maybe you are confused because I haven't been clear. I'm not an expert, but I'll try again.

We run three tests on fuel at the track.

The first is done with an electronic test meter. The meter measures the dielectric constant (DC) of the sample. The DC is a measure of the sample's relative effectiveness as an electrical insulator. The DC of pure gasoline is known. The addition of other substances will change the DC. As it turns out, oxygen bearing compounds added to fuel will raise the DC, hence the table in the GCR specifies a maximum DC by class. Adding oxygen to the fuel can increase the power output of the engine burning such fuel. Unfortunately, the really good (in terms of power increase) oxygen bearing compounds are pretty toxic. Also unfortunately, oxygen bearing compounds such as alcohol or MTBE are often added to street fuel to reduce air pollution, and they will change the DC just as paradioxane will. More sophisticated test methods would allow the club to determine exactly what is added to any given fuel sample. The downside to that is cost and convenience. A quick browse around the internet tells me that a gas chromatograph would cost around $25-$30K. It would probably need to be used in an air conditioned building (cost?) and be operated by a chemist (average freshly graduated chemist salary ~$36K; probably $75/hr from a temp agency). The DC test we do now takes about one minute (including cleaning and rezeroing the meter between samples). I have no idea how long a laboratory analysis would take, but I'd bet a lot of racers would leave the track for home with their group's results still listed as 'provisional'.

OK, the next two tests are easier to explain. We put a few mL of the sample fuel into two test tubes and add a drop of test chemical (commonly called a reagent) to the sample. If a precipitate forms in the bottom of the test tube, the fuel sample fails. This tells us if certain other chemicals have been added to the fuel. I have no idea what the test chemicals are, or what they are testing for. IT, SM, SS, T and SRF (I think) are a little different; if a precipitate forms in the 'A' test that is white (or anything other than black) the fuel doesn't fail. I believe this is to allow street fuel in those classes. The next time I talk to Chemical Ira, I'll see if I can get any more details on the reagent tests (but don't hold your breath, see below).

You ask why we can test

Eric

I think you've summed it up nicely in your first paragraph. In your second paragraph you ask if better equipment could test for everything, and if it's really necessary to test for everything. I'm not really sure, but I believe that a gas chromatograph or possibly a mass spectrometer could tell you the exact makeup of the sample. I, personally, don't think that's necessary and the club must not either; as we're not doing it now.

OTOH, if you start testing by looking for specific adulterants, as soon as the cheaters figure out what you're looking for they'll find something different that your test won't detect. I suspect this is why I haven't been able to find out what the current reagent tests are, or what they're looking for. The company that supplies the test chemicals won't sell them except to a sanctioning body. That only slows the determined cheaters down, of course, it won't stop them.

Finally, what you say in the third paragraph makes a lot of sense. Is it practical? I don't know, but this is exactly the sort of thing I was thinking of when I called for questions. The people I can ask aren't rule makers, but they're probably the closest thing the club has to fuel test experts. The rule makers aren't fuel test experts, but they probably would be open to information from someone who is. I really believe that they (the CR have our best interests at heart in this matter, and they want to do their best to keep us from poisoning each other in our quest for a plastic trophy without going too far overboard in either money or time expended.

On a side note, SCCA isn't the only sanctioning body to use the same instruments and chemical tests to screen fuel, so if we're doing it wrong, at least we're not alone.

Keep 'em coming.