How much does Fuel weight?

[98 tigershark]

Allot of attention is given to how much air and at what density it is when it enters the Motor but what about the fuel? On an average day lets say the outside temp is 65 degrees F. Fuel become less dense when the outside temp is 90 degrees F. We know fuel in a fuel rail can percolate around 190 degrees F. So since the injectors size is measured in Lbs per hour or G/S at a given PSI. How do you make adjustments for the change in the Fuels density, temp? One way is to put a regulator after the fuel rail and return line back to the tank. Then we also have the problems of fuel line size, fittings all that affect flow and would be affected by the changed fuel temperature and density not to even mention the static electric charge from high flow/pressure EFI fuel systems (plastic inside the fuel lines can cause more static charge).
So is there a better way as an IBPW is a time measurement based on the injector size and flow and does not have an adjustment for fuel temp and density.
I feel fuel temp and density are as important as the correct calculations for VE and or AFR. Then what about a dirty or aged injector or the fact that most new ones that are the same size can be different by as much as 10-15%. Air flow is very important as a good motor is an efficient air pump but to achieve the combustion we desire we also have to pay attention to the Fuel.
98 tigershark

[joecar]

One reason GM used the returnless system is that warmed up fuel is not being returned to the tank allowing the EVAP pressure test to pass more easily... i.e. GM optimized the fuel system for passing [stricter] emissions standards... it sux.

[gmh308]

In a factory car running closed loop, it is all taken care of. :)

And hot fuel under the hood is why racers run fuel as well as intake manifold cooling setups.

Anyone seen movies of LA streets in the early 70's?

Air is clean now. Lower HC emissions is one of the enablers, so I am a fan of GM keeping tank fuel cooler by not circulating it up front :) and delivering cool fuel to the rails. Also higher line pressures help reduce boiling, and with DI motors that'll be a thing of the past.

Though fuel that is too cold does not vapourise as well, which means poorer part throttle response and mileage. Its all a juggle. :)

[mr.prick]

One reason GM used the returnless system is that warmed up fuel is not being returned to the tank allowing the EVAP pressure test to pass more easily... i.e. GM optimized the fuel system for passing [stricter] emissions standards... it sux.
I thought they did this to save money,
but GM doesn't need money any more since they got that new
high rolling investor. :hihi:

[redhardsupra]

fuel temp does play havoc on fueling. after driving for a while go to a gas station and fill up with nice cold fuel from the in-ground tank, and the trims are gonna go nuts for the first few minutes, and then they're gonna stabilize again.

i dont know of any table that would account for that. so closed loop wins again.

[98 tigershark]

How about 178 Lbs. How come on a warm day I am a little taller but weight the same?
98 tigershark

I thought they did this to save money,
but GM doesn't need money any more since they got that new
high rolling investor. :hihi:

[98 tigershark]

Take a bucket with 7 Lbs of gas and cool it to 50F degrees. Do the same with another bucket and leave it at 90F degrees. Put them next to each other and the 50 degree F gas will take up less in the bucket by more than I thought. I live in the NW and right now we are having almost record temps. I wonder if the thinner hotter air comes close to the fuel being less dense also given the same temp. Fuel is a liquid and air a gas so I think the fuel is still something to seriously think about. I think?
98 tigershark
98 tigershark

[odd boy]

I am a chemical eng working in a refinery, here is the data that you need. if we assume that the operating temp is between -15_C "5_F" to 40_C "104_F" the % difference is only 5% which can be ignored.

5925

[98 tigershark]

Thank you very much as that was exactly what i was looking for.
That is fairly close to what I calculated with the 7 lbs of gas in a bucket test at a cooler temp than it is now (100 degrees out side).

I am a chemical eng working in a refinery, here is the data that you need. if we assume that the operating temp is between -15_C "5_F" to 40_C "104_F" the % difference is only 5% which can be ignored.

5925

[98 tigershark]

I recently saw some tuner races on speed TV and some info about the rising popularity of fast cars in parts of the middle east. I think it was in Dubia. They had some pretty cool cars and a silver Corvette C6 ZO6 in particular. Are you close to there?
98 tigershark

I am a chemical eng working in a refinery, here is the data that you need. if we assume that the operating temp is between -15_C "5_F" to 40_C "104_F" the % difference is only 5% which can be ignored.

5925

[odd boy]

I am in Saudi Arabia. I am about 10 hrs driving from Dubai. Actually, we have a good drag racing team as well as some cars for show. You can see some videos for us in the youtube, we did many GM, ford... cars. Unfortunately, the member who is in charge of the Chanel is very busy to do frequent uploads.
I am the one who is setting always to the side of the car. We actually tune all ECU’s “US, European, and Japanese”

http://www.youtube.com/results?search_query=powermakerdyno&search_type=&aq=f

Here is a friend of the team at the track.

http://www.youtube.com/watch?v=I7Ow1pkUSn4

[98 tigershark]

That was a cool uTube. I have dial up and it takes quite a while to load but it was worth it. I had no idea there was a drag strip in the middle east. I was trying to watch the tach during the run and the best I could tell was the car seemed to go to 9-10,000 RPMs. Good luck with the new business and keep me in mind when you come across some new cool stuff. My daughter took a video of my vette in a drag race and I am going to try to post it as soon as we have high speed internet available. The video is the only proof I have of how fast my 98 vette is since the drag strips around were we live prohibit going under 11.5 seconds in the 1/4 mile, without doing some pretty ugly things (ugly but important safety wise) to your street rod. You do not get the time slip and get in trouble in the event you go under that time. Since it was a test and tune run I can still race just as long as I do not ever repeat that run, ever!. I wont publish the time until I am able to post the video as that says it all just as in the video you attached. 100 plus octane fuel makes a very big difference. Do you formulate or mix your fuel?
Best wishes,
98 tigershark

[odd boy]

I do my race fule my self, last time I did 104 oxygenated. Our pump gas is 95 octane and $8/gal. Also, we do purchase VP racing fuel.

[98 tigershark]

By the way I think you are in the right place at the right time for your business and I am certain you will do very well.
If we are lucky, we have 92 octane at the pump. Then when I race I have a special all the around race tune including the tranny. When at the track, I usually have close to 6 gallons in the tank of supposedly 92 octane and then I use 110 octane at a ratio of 3 to 1 or 2 gallons of 110 octane that costs around $15.00 a US gallon.
So are you talking imperial gallon prices or US. Is it true that a barrel of gas or oil has 55 US gallons (3.75 liters per gallon) and 44 imperial gallons(4.55 liters per gallon)in the middle east. So by US standard are you paying an equivalent as to the $8.00 a gallon? In any event that is a surprise and very expensive. If you have any advice or recipe on fuel mixing I would appreciate it very much and be in your debt. I am somewhat capable as I use to own a chemical blending/formulating and mixing company for water treatment (20 years ago).
Thank you,
98 tigershark

[98 tigershark]

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