JDMKid71

Well first of all i searched around and most of the topics having anything to do with octane happen to be high comp. engines and worrying about how high they can go with 91 octane. i however want to know if its going to hurt my engine. I have a D15B7 Engine with the S20 (EX) tranny and a 7lb light weight flywheel.. I was wondering if i filled my car up with 91 octane if its going to hurt my engine and the internals? Any coments are helpfull, i just dont want to blow my engine or a gasket or something. Thanks

TJ

Kamin

it wont help and thats why its worthless.

octane is a measure of how hard it is to combust a fuel. the higher the number the harder it is to combust. octane does NOT equal horsepower. theoretically you need the lowest octane you can run without detonation. your engine being near stock, you do not need anything above 87 octane.

Kyles ej1

the only thing its gonna hurt is your wallet

pdiggitydogg

Only thing its going to hurt is your pocket.
You dont need 91octane. 87 is just fine.
Go with the lowest you can use without knock

LoganMantits

it shoudlnt, theres a good article in this months superstreet about octane go pick it up.

JDMKid71

haha alright. as long as i dont have to worry beating the hell out of my engine im not going to worry about it. thanks again

VashTheStampede

If your compression ratio is below 10, then use 87. No problems there. If it were a B16 which is designed to run on japanese 95 octane, then I'd be a little more worried. The only problem you will have is knock.... which can lead to bigger problems down the road. If you're still scared, use an octane booster.

Kyles ej1

whats japanese 95?

Kamin

japan uses a different octane rating called the RON system. the numbers are higher but the octanes arent that drastically different than ours.

JDMKid71

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VashTheStampede &raquo;</TD></TR><TR><TD CLASS="quote">If your compression ratio is below 10, then use 87. No problems there. If it were a B16 which is designed to run on japanese 95 octane, then I'd be a little more worried. The only problem you will have is knock.... which can lead to bigger problems down the road. If you're still scared, use an octane booster.</TD></TR></TABLE>

Not sure what you were getting at? my question was if im running TO HIGH octane already.. not if i need more. didnt you read the first post.? its a STOCK D what stock D do you know that has a comp ratio over 10:1?

thrty8street

iTrader: (7)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kamin &raquo;</TD></TR><TR><TD CLASS="quote">japan uses a different octane rating called the RON system. the numbers are higher but the octanes arent that drastically different than ours. </TD></TR></TABLE>

lol somones been reading Sport compact car

JDMlyfestyle

87 or 89 will be fine for you TJ. ignore these cali guys. there maxed out on 91. when we got 87-105

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thrty8street &raquo;</TD></TR><TR><TD CLASS="quote">lol somones been reading Sport compact car</TD></TR></TABLE>
sorry the only magazine i read is grassroots motorsports, and some karting magazines. 90% of the "mainstream" magazines are bullshit and have biased articles because they are afraid to **** off an advertiser.

thrty8street

iTrader: (7)

alright chill, you got it, i thought you read it because the latest issue has an article on ocatane levels and it mentioned the RON system

Marteinn

hi

i always use 98 octane on my eg6 civic VTi B16a2 engine and i live in iceland europe

i can also get 99+ v-power on shell

just wanted to say this :D

goda nott fra islandi

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thrty8street &raquo;</TD></TR><TR><TD CLASS="quote">alright chill, you got it, i thought you read it because the latest issue has an article on ocatane levels and it mentioned the RON system</TD></TR></TABLE>
just saying, nothing against you or what you said

Redline96LX

93 Octane in your motor, you will be totally safe.

JDMisGOOD

Just run 87 save yourself some change.

Jedi_Sol

Basically, octane is a rating of how far the gasoline can be compressed before it detonates (knock/ping/etc).

If you have an engine that requires 87 octane and you put in 87octane gas, the spark plugs will ignite the gasoline the moment before it detonates... no problem here.

If you have an engine that requires 91 octane and you put 87octane gasoline in there, the 87octane gasoline will detonate (knock, ping, etc) inside the combustion chamber because it has reached its compression point BEFORE the spark plug was able to ignite it... bad.

if you have an engine that requres 87octane and you put 91 octane gasoline in there, when the spark plug ignites, not all of the octane will be used up, thus leaving unburnt fuel in the combustion chamber. And since gasoline is a hydroCARBON, unburnt fuel will eventually turn into carbon buildup... which is bad.

I hope this made sense.

James

longbeachpurplecivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jedi_Sol &raquo;</TD></TR><TR><TD CLASS="quote">Basically, octane is a rating of how far the gasoline can be compressed before it detonates (knock/ping/etc).

If you have an engine that requires 87 octane and you put in 87octane gas, the spark plugs will ignite the gasoline the moment before it detonates... no problem here.

If you have an engine that requires 91 octane and you put 87octane gasoline in there, the 87octane gasoline will detonate (knock, ping, etc) inside the combustion chamber because it has reached its compression point BEFORE the spark plug was able to ignite it... bad.

if you have an engine that requres 87octane and you put 91 octane gasoline in there, when the spark plug ignites, not all of the octane will be used up, thus leaving unburnt fuel in the combustion chamber. And since gasoline is a hydroCARBON, unburnt fuel will eventually turn into carbon buildup... which is bad.

I hope this made sense.

James</TD></TR></TABLE>

thats some good stuff yo

Jedi_Sol

just trying to spread wisdom and knowledge to those who seek it

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skylinedo &raquo;</TD></TR><TR><TD CLASS="quote">
picked up the Turbo Elise issue of SCC, the Elise/EvoMR articles are good reads. has some suspension tuning tips too

dont' see what's so bad about it</TD></TR></TABLE>
SCC is marginal. ive read some decent stuff and ive also read crap.

Jedi_Sol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kamin &raquo;</TD></TR><TR><TD CLASS="quote">
SCC is marginal. ive read some decent stuff and ive also read crap. </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skylinedo &raquo;</TD></TR><TR><TD CLASS="quote">
picked up the Turbo Elise issue of SCC, the Elise/EvoMR articles are good reads. has some suspension tuning tips too

dont' see what's so bad about it</TD></TR></TABLE>

ha, in only 30min, this thread turned from a discussion on octane into a discussion on which magazines are crap, not so good, decent, etc...

good times

Kamin

this thread was solved after the 3rd reply telling him it wont do anything. its ripe for the stealing.

96turboek

just like everyone has said, you only need 87 octane. dont waste the money on 91 if you dont absolutley need it.