Race fuel, Few questions?

[v8ter]

1) f I want to use 100% race fuel, Im going to drain the tank , how many gal should I use for about 5passes?

2) And lets say I only do 2 passes, can i drain the fuel into a clean container and reuse it later again?

3)And which fuel can you mix 50/50 93/race fuel ,without having tune issues because the fuel stoich is different ?

4) How do I mix the fuel? Get the car to almost empy and add the race fuel or mix 50/50 in a container and add it to the car?

Sponsored

 

[Inigo]

1. As much as you'll need to get 5 WOT's. Then add 10% to the gallon amount you have in tank. You should have enough fuel to cool the pumps during the entire performance. Remember, the fuel will shift away from the pickup during a hard launch. You want enough fuel to maintain reliable pickup during the performance. You will have to compute the amount of fuel used during a 10-13 second WOT pass.

2. Technically yes, but I wouldn't recommend it because its time consuming and not needed. If its unleaded race gas then you can mix it with regular pump (your AKI will go up which is a good thing). You can ALSO mix leaded with pump. Notice: If you have CATS, you might not want to run leaded for extended periods of time. Leaded fuel can damage oxygen sensors and your CATS. Lead deposits inside your CAT will degrade there performance. http://www.sunocoracefuels.com/tech-article/race-fuel-101-lead-leaded-racing-fuels

3. You can mix any ratio you want. Your knock index will rise with higher octane fuel. If your tune is for pump, you will only see limited gains running race fuel, if any. Your tune will advance timing to its maximum potential but based of the pump tune you have (because its tuned for pump gas). If you have a race fuel tune then you need to use the same quality and quantity of race gas used during the tune. This will ensure your tune exploits the higher octane and increased knock resistance the fuel provides. http://papers.sae.org/2006-01-2998/

4. Mix fuel by starting off with your desired amount of pump in the gas tank and then pour in your race fuel (desired amount) to give you the ration/octane level you desire.

http://www.motorsportsracingfuels.com/OctaneCalculator.html

 

[Trey@Hypermotive]

^^^^ Nailed it, id put about 1/2 a tank to be safe. so 6-7 gallons.

 

[phunk]

I can fuel starve my car on the street at about 1/3 tank. I can imagine that the greater acceleration forces at the track would demand at least a 1/2 tank for a safe, starvation free pass.

I second the notion for 1/2 tank minimum.

 

[Phoenix]

i raced on a 1/4 tank once. on a 1.7 60 foot the car was fine.

1.68 and it starved for fuel and sent the car into limp home mode.

half tank or more. gasoline weighs 6lbs/gallon approximately.

 

[ramirj2]

1) f I want to use 100% race fuel, Im going to drain the tank , how many gal should I use for about 5passes?

2) And lets say I only do 2 passes, can i drain the fuel into a clean container and reuse it later again?

3)And which fuel can you mix 50/50 93/race fuel ,without having tune issues because the fuel stoich is different ?

4) How do I mix the fuel? Get the car to almost empy and add the race fuel or mix 50/50 in a container and add it to the car?

3) I was looking into this and was advised ( by one of the Whipple guys here) that I can run pure 110 without an issue on my stage 2 (72’s) .
Currently I have the 3.375” on Whipple tune and had done a roll race event to 1550 ft with straight Sunoco 104 without any issue.
How much boost are you running?

 

[whatsup62]

I would hit up your tuner and get a dedicated race tune so you can take advantage of the better fuel. With just a 93 tune you are wasting money putting race fuel in it...unless 93 isnt available to you.

 

[v8ter]

Well Im going to use a dedicated race tune for 100% race fuel, and if I have to use 1/2 tank and only do 5 passes and mix it with pump I think I would waste alot of it away, do you guys know if I could remove it and put into a clean container and reuse it again next time I go to the track ?

But I was told the stoich on the race fuel was different and that would mess up the fuel tables and I would lean out when mixed with pump fuel on a pump fuel tune?

 

[v8ter]

3) I was looking into this and was advised ( by one of the Whipple guys here) that I can run pure 110 without an issue on my stage 2 (72’s) .
Currently I have the 3.375” on Whipple tune and had done a roll race event to 1550 ft with straight Sunoco 104 without any issue.
How much boost are you running?

Im running a 3.5" at 7psi(lund boost box) Im at over 6000feet 9000da

 

[ProChargerTECH]

1) f I want to use 100% race fuel, Im going to drain the tank , how many gal should I use for about 5passes?

2) And lets say I only do 2 passes, can i drain the fuel into a clean container and reuse it later again?

3)And which fuel can you mix 50/50 93/race fuel ,without having tune issues because the fuel stoich is different ?

4) How do I mix the fuel? Get the car to almost empy and add the race fuel or mix 50/50 in a container and add it to the car?

1) I hate ever running a FI car with less then 1/4 tank. (Personally I would do 1/2 tank) So 8 gallons

2) Yes, you can drain it and reuse it

3) There is no difference in AFR between race/gas and pump gas

4) Get a 5 gallon container. Fill it with 2.5 gallons of 93, then fill the other 2.5 gallons with your race fuel. Instantly mixed 50/50





I am very very used to swapping fuel, and mixing fuel. After all I am a dirtbike guy.... "Mixing gas, and hauling a$$"

 

[Tommy V]

Why is then when tuners do ms109 tunes they tend to run the a/f a little richer then 93.I noticed this on my logs between the two fuels.I asked Jon about it and he said it was because the 109 was oxygenated and needed to be run a little more on the rich side

 

[F1scamp]

From using oxygenated fuels in other cars, I have found they make more power with richer mixtures than conventional race fuels. One of my cars made peak power at 13.4:1 a/f on C16, switched to C45 and it liked 10.8 a/f.

 

[Tommy V]

From using oxygenated fuels in other cars, I have found they make more power with richer mixtures than conventional race fuels. One of my cars made peak power at 13.4:1 a/f on C16, switched to C45 and it liked 10.8 a/f.

That makes sence and thats about where my a/f is at idle with ms109.What i dont get is these computers are able to compensate a good bit for a/f mixters,i dont see why it needs a tune adjustment for some of these different fuels with how much room the pcm has to make adjustments.

 

[v8ter]

That makes sence and thats about where my a/f is at idle with ms109.What i dont get is these computers are able to compensate a good bit for a/f mixters,i dont see why it needs a tune adjustment for some of these different fuels with how much room the pcm has to make adjustments.

A tuner should share a bit of info on this

 

[ProChargerTECH]

A tuner should share a bit of info on this

I would love to, but frankly, I am buried in files to get out today.

If you want to really read up on this stuff, (and not just internet gossip)
There are a lot of engineering white papers that will dive into great detail about it. Covering topics like MBT, Flame speed, Detonation, Octane, and AFR for peak TQ production.

Just a topic on the debate between the relationship of timing advance vs. AFR and effect on EGT's is a great place to start.

Sponsored