so i dont know much about race gas..

[hottscennessey]

...but if my understanding is correct. Race fuel will NOT alter the A/f ratio, is that correct? It is just safer to prevent from detonation allowing turbo cars to run more boost?

The reason i'm wondering, is i need to tune my car after i have installed my maft, and i want to be safe before tuning it for ~WOT. I'd really hate to blow my motor. This is a completely seperate question, but would it be wise to up the signal considerably just incase its lean ~WOT?

 

[GotToyota?]

I think so. My friend put in it his Prelude without altering anything, worked like a charm.

 

[chevyeater]

The specific gravity of a given fuel can have an effect on the A:F ratio in an open loop system since you are injecting a set volume of fuel (for a given pulse width) to accompany a set mass of air.

 

[hottscennessey]

hmm, so yes, but i dont understand..

 

[boost fiend]

higher octane fuels are made to burn diffrently. diffrent amounts of air. i run a cheap a/f meter and when i run cam2 (111 octane! %5.75 a gal. here) i see a change in ratio.

 

[hottscennessey]

So i'm guessing it makes it run richer.

 

[chevyeater]

So i'm guessing it makes it run richer.

Not nessicarily. The average specific gravity of pump fuel is around .75. If the racing fuel you put in has a higher specific gravity, it will run richer. If the racing fuel you put in has a lower specific gravity, it will run leaner. Most typical gasoline products (pump and racing) are relatively close to the same specific gravity so the differences are not especially dramatic, YMMV.

 

[hottscennessey]

Okay perfect, that explains a lot. Thanks man.

 

[lagged]

(dont boost on it until you tune it)

 

[hottscennessey]

i've been sucessful for 2 months now (cruising, no boosting). I'm tuning it by myself tho, so i've gotta boost at least once (not all out WOT) to see where my A/f's are at.

 

[derK]

i always thought that race fuel just doesn't detonate as easily in high heat temps so it'll allow you to run more power/boost????

 

[boost fiend]

oh you get more power. dont get me wrong.

 

[lagged]

"race gas" wont give you more power alone. it will simply allow you to run more boost.

 

[figgie]

if the car is not tuned for race gas. Don't go crazy with boost until you get a solid baseline and tune it!

 

[hottscennessey]

yea, i understand that. I'll probably only tune for 16 PSI (SP61GT).