Race fuel and tune?

[Crazy jok3r]

Hey Everybody

i wanted to know if you can mix race fuel with pump gas, and if you can do you need to tune your car. Also what is the ratio of race fuel to pump gas do you do?

 

[Scott8583]

If it's not oxygenated you don't need to change the tune... I've spiked 10gal of 93 with 2gal of 110 leaded & I've also ran it 50/50 mix... Leaded didn't hurt my 02's like everyone says it will.

 

[Crazy jok3r]

Thanks for the info

 

[Crazy jok3r]

Also does anybody know where you can get race fuel in the Tampa area?

 

[beefcake]

I've seen cars kill 02 sensors with just a couple gallons mixed in first trip out. I've seen some live a long time.

You really should have a tune for the proper stoich mix of your fuel. The cars have adapative learing, and can learn the fuel, but it does take some time.

In addition, if you don't have a tune for the fuel, whats the point?? If your not tuned for the higher octane, their is 0 benefit to adding it.

 

[darreng505]

Maybe zero performance benefit but there are other benefits of high octane fuel.....

 

[beefcake]

Maybe zero performance benefit but there are other benefits of high octane fuel.....

what would be the benefit of a higher octane fuel if the car isn't tuned for it?

if the stoich is too low on the race gas, you could actually run the car lean, and hurt the engine.

you put In a race fuel with a stoich value of around 10 to 11, vs your normal 14.64 and go out and make a wot blast, you could be running 20% plus leaner

there is no benefit in that.

 

[scott_0]

Leaded fuel will kill your wideband sensors over time, plus there are no real benefits unless you're tuned for it with aggressive timing, or if you're seeing excessive timing being pulled do to bad fuel, if you insist on running race fuel, use the unleaded stuff

 

[Voltwings]

what would be the benefit of a higher octane fuel if the car isn't tuned for it?

if the stoich is too low on the race gas, you could actually run the car lean, and hurt the engine.

you put In a race fuel with a stoich value of around 10 to 11, vs your normal 14.64 and go out and make a wot blast, you could be running 20% plus leaner

there is no benefit in that.

Depends on the timing threshold your tune allows. If the higher octane allows the computer to add timing (and assuming your tune was not already adding the maximum timing it was allowed) there could be a performance benefit. Also depends in what situation you're using the gas, the benefits of race gas go beyond the fact that it simply combusts and makes power, such as race gases improved ability to perform on a road course.
I've cut my 93 road race tune with 50/50 98 on occasion and fuel trims always seem to check out ... Unless the fuel is highly oxygenated, i dont see how "gas," could have different stoich simply based on its octane rating. Especially enough to matter when its done in a blend (obviously the degree of the blend matters). Isnt the Specific Gravity of most "race Fuels" higher as well? I'd expect that to make you run richer if anything.

 

[Scott8583]

I should clarify... I was using leaded race gas as a band aid. Just running it on the weekends I would go to the track (actually that was a lot of weekends). I was making 600whp in an A6 on stock fuel pump & 47lb injectors. I knew I was going to get a fuel system & run E85 next year & didn't want to waste money on a booster pump. The Coyote 02's are a lot more durable & less expensive then older models. I data logged before & after trying it & my logs were fine. I even added 4 deg of timing and 1 size smaller pulley. Data logs were fine. I never had a problem & know a couple others that have not had a problem. But like I said, it was a temporary band aid

110 was $7 gal... (Cut 50/50 = $5.50)
104 unleaded was $11 gal

 

[Aaron@JPCRacing]

You can mix them if the stoich is roughly the same as gas (like Fuse 116 or Mach 116)

Unless your tune is setup for it though your just throwing money away.

 

[Crazy jok3r]

Thanks for all the good info.

The reason I am asking is because I am taking my car to the drag strip this weekend, and I want to add just a little race fuel to help out in case I have some bad pump gas. I really wanted to know if I could add a little race fuel with pump gas with out having to get another tune, or would getting ethanol free 93 octane pump gas be a better option for me?

 

[Bdubbs]

Why not throw in a can of torco for safety if you basically just worried about a little bad pump gas?

 

[blackcoyote13]

The stock tune runs even better with higher octane, up to a peak that I've seen around 98 octane. I run a mix of 6 gallons MS100 (unleaded, relatively close stoich) with 1-2 gallons of 93 pump for a proper half tank at a time. Car made close to 400whp with stock intake, Kook 1-7/8 shorties, GT500 mufflers through an M6 and an AED tune on that gas. I highly recommend the gas if you can justify the cost

 

[Crazy jok3r]

Where can you buy it at?

 

[beefcake]

Sounds like everyone else has this covered. I wouldn't pay attention to the guys with 7 and 8 second cars that do this everyday.

 

[Crazy jok3r]

Sounds like everyone else has this covered. I wouldn't pay attention to the guys with 7 and 8 second cars that do this everyday.

What about ethanol free 93 octane pump gas?

 

[beefcake]

You need to look at the stoich of the fuel, just as we have said. If the stock is close your fine. You will be amazed at how current some of the stoichs are. That's all were saying. The lower the stoich. The leaner the car will run.

 

[Crazy jok3r]

You need to look at the stoich of the fuel, just as we have said. If the stock is close your fine. You will be amazed at how current some of the stoichs are. That's all were saying. The lower the stoich. The leaner the car will run.

How do you go about finding the stoich?

 

[beefcake]

How do you go about finding the stoich?

Most manufacturers will have it on their site.

You have to remember, guys like me and Aaron, yes were vendors, but we're here to help to. Our goal is to help keep your engines / cars alive and running well.