race gas

[1toofastlt1]

They have 100oct. at a station near by. I tuned my car on 91 if I put 100 without changing the tune will I get any more power?

[jakesz28]

No.


If your car runs on 91 octane then it is safe to say you didn't build a high compression motor. A friend of nime spent 5-6 hours on an engine dyno with a 500+ cubic inch motor with 12 to 1 compresion. They played with timing, AFR, ect. Strated with 116 octane then went to 112 ended up on 93 octane. It made more power on the 93 octane a was 700+ hp from 5000 rpm and up.



EDIT I just noticed you had the supercharger listed in your sig. If you wanted to give it more timing or boost with the higher octane there is power to be had.

[popo8]

Is 100 octane leaded.... I know the 112 and the 116 we have at the shop is....

THe reason I ask is, I dont think its good for the cats (if you have em) to run leaded...

[Z28pr0jekt]

Is 100 octane leaded.... I know the 112 and the 116 we have at the shop is....

THe reason I ask is, I dont think its good for the cats (if you have em) to run leaded...
100octane is usually unleaded.

But I've seen gases up to 116 unleaded.

Correct, it can clog the cat and moreover it can foul out the O2 sensors. Generally running it once or twice shouldn't cause much damage but if it becomes a regular thing it can definitely wear on these parts

[1toofastlt1]

So i had about a third tank of gas and i just put 3 gal of the unleaded 100 and it feels like I have 80 more hp. I couldnt believe my ass dyno. ha ha.

[jakesz28]

The power of sugesting is amazing.

[popo8]

The power of sugesting is amazing.


absolutly... like back when I used to throw 3 cans of octane boost in my BIRD before a race... lol!

[Z28pr0jekt]

So i had about a third tank of gas and i just put 3 gal of the unleaded 100 and it feels like I have 80 more hp. I couldnt believe my ass dyno. ha ha.
The only way that would happen is if your car was detonating on 93 and pulling timing and now with the extra octane it is no longer pulling timing

[Spartan7]

So i had about a third tank of gas and i just put 3 gal of the unleaded 100 and it feels like I have 80 more hp. I couldnt believe my ass dyno. ha ha.

:laugh: SOTP dyno huh?

Common misconception about octane. Hell, I watched some lady dump 91 into her minivan, and just laughed my ass off. It has nothing to do with being "better" gas or having more potential energy. The purpose of higher octane is to reduce the chance of predetonation, plain and simple.

Usually adding lead to gas is a cheap and easy way to bump up the octane, which is why some of them are leaded. But yes, like Z28pr0jekt said, it will clog the cats and foul the O2s.

[1toofastlt1]

im very new at tuning and I tuned my car from stock So there is a chance I have too much timing for the 91 oct here in cali.

[Fire67]

If you didnt tune it on the dyno, and instead used knock data on the street, chances are that the timing is well past the point were it makes peak power. And on the ragged edge of detonation.

With that said, the increased octane is probably able to use the extra timing and therefore improving the SOTP feel.

[BLOWNDFIZ]

If you didnt tune it on the dyno, and instead used knock data on the street, chances are that the timing is well past the point were it makes peak power. And on the ragged edge of detonation.

With that said, the increased octane is probably able to use the extra timing and therefore improving the SOTP feel.


The underlying message from the above post is get that thing on a dyno and run some logs before you are paying for a rebuild...

[1toofastlt1]

yikes sounds good

[Fire67]

The underlying message from the above post is get that thing on a dyno and run some logs before you are paying for a rebuild...

EXACTLY!!! :cool: