Cost effective fuel tester

[CDMBill]

On a related thread in the Drag Week section we've been discussing pump gas motors. It raised the question what is pump gas, or more particularly what is in it? Most places have some alcohol in their pump premium, but how much and what risk am taking with a relatively high static C/R of 11.86:1?

So what is best method and tools needed to assess what I just put in my tank and any changes I'd make to the tune (richer/leaner)?

[TC]

On a related thread in the Drag Week section we've been discussing pump gas motors. It raised the question what is pump gas, or more particularly what is in it? Most places have some alcohol in their pump premium, but how much and what risk am taking with a relatively high static C/R of 11.86:1?

So what is best method and tools needed to access what I just put in my tank and any changes I'd make to the tune (richer/leaner)?

Vizard did a pump gas comparison, they tested pump gas from different gas stations, lets just say not all pump gas is created equal, and some pump gas has detonation resistance almost as good as race fuel which is what they used to get their baseline..........

[A/Fuel]

Anton Paar makes density testers, in your case it would probably tell you the percentage of alcohol.

http://www.anton-paar.com/Facts-Figures/7_USA_en

The nitro tester is pretty expensive, about $2500 but it's handy and quick. All you would need though would be a hydrometer with a thermometer, and a chart.....right? Nitro ones go for about $150 with a nice case to carry it around.

[BBR]

http://www.quickfueltechnology.com/s...test-tube.html

Bill couldn't you use the Quick Fuel E85 tester in reverse?

[CDMBill]

That's a good question James. Can I? the calibrations would seem to require interpolation at best, but it might be a guideline.

Check this out per A fuel.

[JeffMcKC]

Bill there is so many variables, Doc has a homemade digital meter we flow fuel in a loop for E-85 with. But on "Pump gas" I prefer to bring the fuel on Drag Week so I dont have to tune every day. I dont think you can get enough info off just specific gravity, it moves around a TON, when we raced "Stock Apearing 100cc" Go Karts we would buy the lightest fuel we could bringing the weight up with Nitro Benzine Gold Label/Acetone to the Spec. gravity weight. It checked as stock fuel, well they caught on. I showed up there was a guy with a baby bottle 1/4 fuel of water and a line to the top of the fuel, poured in our fuel check, I asked what was going on, they shook it up and it should come back to the line, well mine did not gas does not mix all the other "Blend" I had did mix and the line moved.

My sugestion is bring the fuel to be used you wont figure it out and may even make it worse by using the wrong tool to measure it.

[Thumpin455]

More ethanol will help raise octane and ward off knock, its what they mix with it that matters more. Usually they mix the lowest octane crap they have with ethanol because it raises the octane so much. How to tell what the other stuff is without a lab? I dont think there is a way to do that.

Ethanol is the same stuff no matter what it comes from, and its properties are pretty constant considering temperature and other factors. You could always tune for 30% and then add that much to it when you put in pump gas, use the E85 meter to see where it is.

I am going to assume you have a wideband O2 already, so the EFI should be able to compensate for small variances, right? I havent found any difference in tune when running E0 to E25, and a bud of mine has been running E30 through a stock Qjet on an Olds 455. Unless you are ragged edge lean, it shouldnt hurt anything or lean you out too far for the EFI to compensate. 10%-15% is almost inconsequential for most vehicles, but I figure yours is tuned quite a bit closer than most are. Anyway, other than the possible slight lean condition, the ethanol is going to help you with the static and dynamic CR.

[CDMBill]

This is less about Drag Week and more about looking at what I get when I fill up at the pump down the street or across town or what ever. I can keep the tune safe at the drags or other eventsand not be 'too' worried but I'd like to know especially as our state government created fuel crsis has them moving the mixtures around more behind the scenes as the greens fight to make our gas less efficient and push us towards electic cars. This as they try to shut down all the electrical generating plants.

End rant.

[CDMBill]

More ethanol will help raise octane and ward off knock, its what they mix with it that matters more. Usually they mix the lowest octane crap they have with ethanol because it raises the octane so much. How to tell what the other stuff is without a lab? I dont think there is a way to do that.

Ethanol is the same stuff no matter what it comes from, and its properties are pretty constant considering temperature and other factors. You could always tune for 30% and then add that much to it when you put in pump gas, use the E85 meter to see where it is.

I am going to assume you have a wideband O2 already, so the EFI should be able to compensate for small variances, right? I havent found any difference in tune when running E0 to E25, and a bud of mine has been running E30 through a stock Qjet on an Olds 455. Unless you are ragged edge lean, it shouldnt hurt anything or lean you out too far for the EFI to compensate. 10%-15% is almost inconsequential for most vehicles, but I figure yours is tuned quite a bit closer than most are. Anyway, other than the possible slight lean condition, the ethanol is going to help you with the static and dynamic CR.

Good points. What I don't know, and this is lack of experience speaking, is how much more fuel I need to make up for the difference in AFR vs improvements in knock resistance. I do not believe they are linear and equal and I need to read more about it. I don't currently run closed loop in any event when street drving but I could easily enough and that would make up the for limits of my fuel table. I don't run it that lean ay where onthe map at the momnet although Scott would like to see me do that to keep the oil cleaner and avoid washing down the cylinders etc.m not to mention pick up the fuel economy.

I know that is a contradiction in terms with a 588" engine but I'd like to anyway with $5.50 premium. We do not have E85 here at all except to buy barrels.

[MR P-BODY]

There isnt a EASY way to test fuel... forget about testing
octane... thats a very expensive test that requires special
equipment... RVP can be tested if you have a freezer and
a 100* hot water tank(and the pressure "bombs" which is
the vessel that you put the fuel in to test).. alcohol is pretty
easy and cheap to test.... so all in all its not easy to test

[CDMBill]

I don't think I needto test octane as I'm forced to accept what is presented at the pump at face value. 91 octane is just that.

The simpler question is whether I'm buying straight gasoline, or gasoline that has 5%, 10% or 15% ethanol mixed in. I think the tester that James mentioned is on the right track, I'm just looking for a convienent and inexpensive way to determine the mix.