What would be the highest octane gas to use in my car. Its running 10.8 to 1.
With mods in sig..

 

octane doesn't equal power

octane is the resistance to ignite.

with a 10.8 just run 93.

what kind of plugs are you running?

 

I mean on the track.. I ran 112 octane once on the track and my car actually felt like it was slower.. And Im running denso iridum plugs..

 

it felt slower because it was. too much octane was causing inefficient combustion.

use pump gas at the track for your setup, tho 97 octane would be preferable since you're closing in on 11:1 compression. over 100 is a waste of money on your setup.

 

I can get 100 octane here in town.. Would that work?

 

try mixing Toluene with pump gas.

search around for the mixture best for you.

 

the best use for race gas is to use a combination of race gas and advacing your timing. race gas isnt going to help if you do nothing to your car. if your car felt slower then that just means your car is slow. adding race gas shouldnt make your car any slower.

basically you will want to advance your timing just enough so you dont detonate. if you dont know what i am talking about then i guess you are just screwed. sorry if im a dick but my ex girlfriend pissed me off@!#$@#%

 

your not listening
OCTANE DOSENT DO ****
run 92 or 93 whatever is at your local pump.
you only need higher octane with high boost or HIGH compression (11+)

 

Kamin's right.. Octane doesn't really do much for power.. It just aids in making power with other engine components without blowing the whole works..

 

My car (b16a) was faster with 94 Sunoco than 93 Mobil.

It was the same, if not slightly slower, with 10:1 94 Sunoco and 108 race gas.

 

How can you tell that you car was faster? did you run in all the exact same race conditions? i cant believe that you can tell that you car was faster unless you advanced your timing or tuned your motor differently.... if you are going by timeslips i hope you are taking into considering race conditions, driver (even though you may have been the driver both times it doesnt mean your timeslips are going to read the same numbers)

BASICALLY.... dont post **** like this unless you really know what you are talking about, you sound like a jackass

 

geez.......I'm running 13.09 on 89 octane.......gonna break into the 12's with bigger injectors and 87 octane.......just to prove a point.

 

Run your car on the lowest octane you can as long as the car doesn't detonate and it doesn't have to pull timing out. No sense in giving it the good stuff unless you have a standalone fuel management system or are tuning the car specificly for it. My b16a runs 11.6:1 compression with 15psi of boost, its next to impossible for me to get that going on less then 104 octane so all of my low maps up til about 11psi are tuned for 93 octane and i just run more boost at the track. When I run 104 all of the low tuned maps drive exactly the same

 

I usually just run 94 octane.. I think ill just stick with that.. Just was curious if I could get anymore power with higher octane.. Obviously not.. Thanks for the replies.

 

The only way you can get more power out of higher octane is if your motor can take advantage of it. If you have higher compression is obviously one of the situations. If you are running a lot of advance is another. Sometimes it is hard to tell, because you may not hear knock because your knock sensor sensed the knock and your ECU retarded your timing automagically. But octane is an antidetonant, so the more octane, the harder it is to get it to ignite. That's where an MSD ignition can help out and some nice new NGK plugs gapped a little bigger than stock.

 

I could tell because half the summer I couldn't get the thing into the 14's. It was always running low 15's. Every week it would run low 15's and low mph, except on a select few weekends it would just decide to pull consistant 14.7s-14.8s with appropriate mph increase. It just so happened that on a select few occasions I would pump Sunoco 94 into it.

Eventually I realized that maybe the gas was responsible for the .3 sec time decrease. So I just fully switched to Sunoco 94 and never ran a low 15 since (I ran it for about six more weekends).

So, I basically ran a three month experiment with about 80 timeslips, with one variable that changed my times by .3sec. That I, along with many witnesses who always came to the track with me and helped me swap the motor in the first place, decided was the gas. No other variable would consistantly change my time by that much and my knock up my speed by a couple mph. I believe this beyond a reasonable doubt.

You're right, I didn't advance my timing. The knock sensor did.

Don't get too emotionally involved in your posts. It ends up making you sound like a jackass.


[Modified by Lsos, 7:51 PM 11/18/2002]

 

what was your setup that you couldnt break into 14s with until you upped your gas 1 octane and switched brands?

 

My setup was an 89 crx dx with a b16 swap, an aftermarket intake and bigger exhaust. I was slightly disappointed with the car until the gas change.

I don't know exactly why it was faster, as a b16 doesn't have that high compression and should run fine on 91 octane. Perhaps there was a couple pounds of carbon deposit in the cylinders. Maybe someone in Japan increased the compression without me knowing, or maybe Mobil is just crap gas.

Either way, I'm sure it had to do with the gas.

 

well im not too surprised about your time i dont think that the gas had everything to do with it. my stock b16 in my 88 crx dx ran 14.28 first run on street tires.
i still had stock header, no intake, no exhaust and 92 gas with timing at 16 degrees.


so if you were hitting 15's then maybe something was just different about your motor.... maybe you just launched different or something but i still dont think a slight increase in octane and a switch of brands will do that

 

Here is something that pissed me off last week. My timing is advanced and I usually fill up at the 76 station by my house(banners with NO MTBE) and pump in 92 and it never knocks. I was low on gas coming home from work so I stopped at the Shell downtown and filled up with 92. I heard it knocking when I accelerated. So they both claim to be 92, and I know they aren't the same, but good luck proving it. There is definitely differences in gas.

 

Obviously differences in b16s in different parts of the country with different drivers will result in different times. However, when it's the exact same everything except for the gas, on a number of occasions, the probablilities of it being something else get much lower.

In the end, I can't be 100% sure it was the gas, and you can't be 100% sure it wasn't. I guarantee you though, that if you ran that car two days every week for the whole summer trying to figure out why it's so slow, trying for that .1 sec week after week, and then a change of gas magically drops the time by .3 sec making everything perfect, you'd think it was the gas too.

I did get the car down to 14.28 or around there eventually. Heh, I think it was the same time you got the first time. However, every decrease in time I can attribute to something else I did to it, so many times I ran that thing.

Gutting doors + hatch ~.15
Take off exhaust ~.15
Tire pressure + removing seat ~.05
Amount of gas in tank ~.1
Gas ~.25
Weather ~.15

 

87 is more explosive than 93.

You run 93 so your vehicle will adjust the timing as far forward as possible (if you run less it should lower your timing automatically). And it will run smoother.

You also can advance your timing a bit beyond spec to make a little more power, and you should run higher octane with this.

Any other added "performance" you get from high octane fuel is the placebo effect.