Tank filling from fuel can

[kurai]

Hello!
Lately around me its becoming difficult to find high octane fuel (there seems to be a bit of a shortage) but my clio only want to drink that.
Luckily there are some fuel stations which always have it but are really inconvenient to go with the racecar or with trailer.
So I was thinking of going there with daily car and couple VP vented fuel jugs and then refill the car at home.

Jugs have the thin attachment to go over fuel cap flap. But the point is.. how I know when tank is really full?? Fuel pistols have that vent gimmick closing the internal valve.. but my jugs obviously don't. There is some way of making a full tank safely? Just looking at the gauge doesn't feel precise enough since over the first notxh usually can go more than 6 liters of fuel..
Thanks
Its a track car so I cannot rely on mileage.

 

[Brigsy]

Expect a bit of spillage if topping the tank off

 

[Louis]

Put a visible float into the tank

 

[JamesBryan]

Put the dash in test mode by holding the button on the wiper stalk in and turning the key to ignition, then press the button again to scroll around to the digital fuel readout.

That's what I do on track days and it's close enough.

 

[kurai]

That's very very interesting mate!! Thank you so much!!!!! I'll try for sure!!

 

[kurai]

Put the dash in test mode by holding the button on the wiper stalk in and turning the key to ignition, then press the button again to scroll around to the digital fuel readout.

That's what I do on track days and it's close enough.

Thank you so much, since my racecar once was a non-sport i didn't had the trip button on wiper stalk, but Yesterday night I took it of and modified adding an external button for trip computer, I then tried your procedure and it works like a charm!!!!
Usually at which value do you stop filling? Thanks a lot!!

 

[JamesBryan]

Thank you so much, since my racecar once was a non-sport i didn't had the trip button on wiper stalk, but Yesterday night I took it of and modified adding an external button for trip computer, I then tried your procedure and it works like a charm!!!!
Usually at which value do you stop filling? Thanks a lot!!

On track days I only take a 20L fuel can and usually fill up when it says 15-20L, so I usually just put it all in.

Maybe test by putting a set amount in and see how long it takes to react.

 

[kurai]

On track days I only take a 20L fuel can and usually fill up when it says 15-20L, so I usually just put it all in.

Maybe test by putting a set amount in and see how long it takes to react.

Oh I see, thank you for the info, usually I fill it up pretty much at top to avoid starvation problems since I don't have a swirl pot and I run on very sticky tires, and I have a very thirsty engine. Here in italy @ monza we have Biassono curve which is very long and you go through all gears..
Anyway thank you for the precious info! I'll do some testing and take my references. Maybe first time I can undo the pump fill at the desired level, refit everything and just have a look ok that number to take as reference.

 

[kurai]

I add an update to this topic. I brought the car to fuel station and filled it there until first click.
Then checked through suggested procedure and it displayed 51 liters.
So I will take 50 liters as reference for full when manually filling at home from jugs.

 

[JamesBryan]

I add an update to this topic. I brought the car to fuel station and filled it there until first click.
Then checked through suggested procedure and it displayed 51 liters.
So I will take 50 liters as reference for full when manually filling at home from jugs.

51L, it's only a 50L tank 😅

 

[Louis]

51L, it's only a 50L tank 😅

Spilt a litre on the floor

 

[kurai]

51L, it's only a 50L tank 😅

thats what I also thought.. but you know.. a liiitle bit of renault sensor tolerance