ascastil

i have a 97 z28 with just a cai and flowmaster cat back and was wondering if like 114 octane racing fuel would give me better times down the quarter mile.

10secbuick

using leaded fuel in your car will do much more harm than good if you still have the cat.

and aside from that, it wont do anything without a tune for it (less timing etc)

bombebomb

No, people claiming godly power gains by adding race fuel to there otherwise stock engines, are full of it. Just stick with the 93 or 91 whichever. However, after running leaded fuel for a while it will also kill your o2 sensors.

LSWHO

The octane level of your fuel for maximum power is as LOW as you can go without getting knock.

Low octane fuel will burn faster.

If you were to run 87 octane and not see any knock or have any problems with knock retard, you will be faster than if you were having to run 91.

Most of the time when people need much higher octane it's because of boost and detonation.

My Supercharged Grand Prix for instance ran no faster with 105 octane than it did with 91. But I also had only false knock.

Also as far as what was said with the regards to the cat. If the fuel is unleaded it won't harm your cats at all. If it is leaded, then it will foul out O2s and such.



Long story short, it's a waste of money most likely.

Injuneer

Burn speed does not correlate to octane rating. Nor does octane rating correlate to energy content. From the Gasoline FAQ:
http://www.faqs.org/faqs/autos/gasoline-faq/part1/

Stephen 87 IROC

That's about as close to the perfect answer as you can get.

Using a fuel with too much octane can actually slow you down.

Octane is the fuel's resistance to detonation. Under high compression, a low octane fuel can self detonate before the plug fires. Using a higher octane fuel prevents or reduces that. Power gains from using high octane fuel usually means it had detonation problems with lower octane.

Injuneer

You may be confusing detonation with pre-ignition. They are two different things. What you describe is pre-ignition..... ignition prior to the spark plug firing. Detonation occurs after the spark ignites the mixture, due to new compounds formed as a result of the pressure and temperature of the burning mixture. These "end compounds" ignite a second flame front, causing a huge pressure spike as the two flame fronts collide.

What is your basis for stating that "too much octane can actually slow you down"? One possible phenomenon is the presence in some high octane fuel of hydrcarbons with low "specific energy"... less BTU's per unit volume. Since the injector, or to some extent the carb is a volumetric delivery system, low specific energy fuels can reduce HP output. But not all high octane fuels have low specific energy (the reason for including item 1. in the quote above). Some high octane fuels are specifically blended to maintain or increase specific energy, particularly those used for nitrous and forced induction applications. It becomes a matter of selecting the correct fuel, and tuning the delivery system to introduce the same number of BTU's.

mdacton

I don't know all the technical stuff but it will slow you down......not a ton but it will.

I know stockers can pick up or slow down depending on the fuel.