Higher octane?


xXx=BioHazard=xXx
07-18-2005, 03:27 AM
If you would use a boost or spray at all would you pretty much have to use a higher octane gas?

mason_RsX
07-18-2005, 06:57 AM
just spray, im not sure but I would assume so...Boost definately yes, high compression definately yes

but newer engines can have sensors to gague the amount of knock, so if your running low octane gas the engine will read the higher levels of knocking and retard spark timing and lower amount of fuel injected so you will lose alot of performance...and damage to your engine is a major possibility

http://auto.howstuffworks.com/gasoline3.htm
this explains octane and knocking

drftk1d
07-18-2005, 05:16 PM
knock sucks, to avoid it just do 2 things, dont live in california and buy higher octane gas

-The Stig-
07-18-2005, 06:15 PM
knock sucks, to avoid it just do 2 things, dont live in california and buy higher octane gas



Our cars run just fine on 91 octane. :sly:

-Josh-
07-18-2005, 06:26 PM
Our cars run just fine on 91 octane. :sly:


Your standards just suck is all.

CassiesMan
07-19-2005, 12:38 AM
Pfft, 91? I use 93.

JekylandHyde
07-19-2005, 10:01 AM
Who wants a car that runs "fine" ... I rather have one that runs great :D

I run 94 octane at the pump here in PA ;)

Seriously though, cars run best on the lowest octane they can get away with without seeing detonation. Octane is a fuels resistance to blowing up ... you want it to explode! That's what makes power. If it is too ready to explode it will ignite when it shouldn't (knock/detonation) so you need a higher oct.

In the 88, the Suburban and Jekyl I run 87 octane.
Hyde, with the turbo, gets the best I can find.
I am almost always running 110 leaded now.

nissanfanatic
07-19-2005, 05:09 PM
Fuel octane is as mentioned resistance to the fuel burning. Higher octane fuel burns slower.

I run 9.5:1 CR with 10.5psi of boost on 93 octane everyday. I boost on hot, cold, ect days with no problems. Basically, when you encounter detonation on a certian grade of fuel, you can do these things:

1) Lower the compression ratio
2) Run higher octane fuel
3) Retard timing
4) Cool the intake charge better(AKA alky/water injection)

Water/alky injection is a very good solution to running expensive racing gas while still having the power of it.

And as jekylandhyde was touching on:

Seriously though, cars run best on the lowest octane they can get away with without seeing detonation. Octane is a fuels resistance to blowing up ... you want it to explode! That's what makes power. If it is too ready to explode it will ignite when it shouldn't (knock/detonation) so you need a higher oct.

IMO you should run a known safe octane fuel/AF ratio and play with timing to get maximum power. BTW, if you end up having to retard timing lower than 20* Total timing BTDC, you should seriously consider #1, #2, or #4 that I listed above. WI/AI is what I would recommend.

http://www.ka-t.org/klattr1/compressiontable.jpg

We over on the KA-T boards tend to stay away from anything past 18:1 dynamic CR on pump gas. We end up running insanely low total timing and it is just not in any way better to run more boost with less timing.

And on every grade of fuel, there is a knock limit. Or "the maximum and mean cylinder pressures that can be achieved,"

SDSEFI Tech: Pushing it too far. (http://sdsefi.com/meltdown.htm)

Very good read on everything engine destruction related.

CBFryman
07-19-2005, 05:10 PM
ptshhh.... octane= HP =...duh. thats why i run 93 with NAWZ octane booster in my civic dawg.... i even put some pencil lead in there..

-The Stig-
07-19-2005, 06:27 PM
Good post nissanfanatic.

Informative... indeed.

CivRacer95
07-19-2005, 07:59 PM
ptshhh.... octane= HP =...duh. thats why i run 93 with NAWZ octane booster in my civic dawg.... i even put some pencil lead in there..

:eek: Shit my secret is out!!

nissanfanatic
07-19-2005, 09:32 PM
Good post nissanfanatic.

Informative... indeed.

Thanks. http://www.automotiveforums.com/vbulletin/images/icons/icon14.gif

Zgringo
07-20-2005, 02:07 AM
NissanFanatic, You hit the hail right on the head. Very good post, and I'd like to add #5 to it if I may.
For the hard core boost freaks or the ones running big spray numbers, TOLUENE.
With the price of gas, toluene is as cheap as gasoline, and a 4:1 mix we'll make about 98 octane gasoline.
Go to Sherman Williams paint store and ask for toluene paint thinner. It comes from crude oil and is what's used to boost the octane in gasoline by the oil companys.
Also it's legal and will pass fuel tests at the races.

-Josh-
07-20-2005, 10:48 AM
NissanFanatic, You hit the hail right on the head. Very good post, and I'd like to add #5 to it if I may.
For the hard core boost freaks or the ones running big spray numbers, TOLUENE.
With the price of gas, toluene is as cheap as gasoline, and a 4:1 mix we'll make about 98 octane gasoline.
Go to Sherman Williams paint store and ask for toluene paint thinner. It comes from crude oil and is what's used to boost the octane in gasoline by the oil companys.
Also it's legal and will pass fuel tests at the races.


So that's what it's come to for you west coasters eh? Having to make your own fuel cause you got nothin but crap....

drftk1d
07-20-2005, 11:26 AM
Your standards just suck is all.
:1:

-The Stig-
07-20-2005, 07:36 PM
So that's what it's come to for you west coasters eh? Having to make your own fuel cause you got nothin but crap....


It's not crap, my 240z ran great on 91 octane. Especially since the SR20 came from Japan which normally runs 94 octane I believe.

Never had any issues with knocking.

Zgringo
07-21-2005, 01:25 PM
So that's what it's come to for you west coasters eh? Having to make your own fuel cause you got nothin but crap....


:1:

I surely hope you 2 are joking. The US government has placed restrictions on the automotive mfg's and because of this the gasoline mfg's all across the country are bound to produce gasoline to meet the standards the automotive mfg's have been forced to follow. If you eastern people think you have a edge on the western boys I hate to pop your bubble but your a day late and a dollar short.
If you do alittle research into street racing and hot rodding you'll see 90% of it and the original Mfg's started in California. California is the home of the National Hotrod Asso. as it is to the National Hotrod Museum. The world famous Oakland Roadster Show is in California. Most of the National records are held by westerners.
If you think were forced to mix our gasoline because of our "crap" your sadly mistaken. We do it because we can improve on what comes out of the refinerys, but then you really don't care as you perfer to run your cars at a lower performance level. Only those with enough grey matter left between there ears would understand the benefits of higher octane gasoline when going to high boosts or large loads of nitrous.
Don't criticize our knowledge, Correct your ignorance!!

-Josh-
07-21-2005, 01:42 PM
I surely hope you 2 are joking. The US government has placed restrictions on the automotive mfg's and because of this the gasoline mfg's all across the country are bound to produce gasoline to meet the standards the automotive mfg's have been forced to follow. If you eastern people think you have a edge on the western boys I hate to pop your bubble but your a day late and a dollar short.
If you do alittle research into street racing and hot rodding you'll see 90% of it and the original Mfg's started in California. California is the home of the National Hotrod Asso. as it is to the National Hotrod Museum. The world famous Oakland Roadster Show is in California. Most of the National records are held by westerners.
If you think were forced to mix our gasoline because of our "crap" your sadly mistaken. We do it because we can improve on what comes out of the refinerys, but then you really don't care as you perfer to run your cars at a lower performance level. Only those with enough grey matter left between there ears would understand the benefits of higher octane gasoline when going to high boosts or large loads of nitrous.
Don't criticize our knowledge, Correct your ignorance!!


I was joking, chill old man...chill... :tongue:

Since you didn't know i was joking i'll just ignore the shot you took at my intelligence.

Zgringo
07-21-2005, 04:59 PM
I was joking, chill old man...chill... :tongue:

Since you didn't know i was joking i'll just ignore the shot you took at my intelligence.

Josh read my 1st sentance. "I surely hope you 2 are joking."
I was only providing some facts for those thar lack knowledge or believe what you said to be true.http://img263.imageshack.us/img263/6784/avatar25898195di.gif (http://www.imageshack.us)

drftk1d
07-21-2005, 06:08 PM
mama didnt raise no fool

nissanfanatic
07-21-2005, 09:43 PM
Arguing over 2 octane is gay anyways. 1 octane point increase=1psi more boost you can run. O wow. Or just use alky injection and run way more on the gas you have. OR get a larger turbo. Or or or or or or.....

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