daredeezy619

i have a stock z6 motor in my EF. and i heard i'd have to run a higher octane. I'm currently using 87, can anyone confirm this?? Would it run any better?? thanks.

EFstyle

it only needs 87 octane as it is a pretty low compression motor but you can always use better gas

Jas9848

iTrader: (2)

87 will be fine

CRX Toad

87 there is no need for anything more. You won't get any better performance with more octane.

dr_latino999

Unless for some reason you have exceptionally large carbon deposits in your combustion chamber which would raise the octane requirement, but without experimental data, no way to tell.

In short, I'd listen to everyone else before I talk about the dangers of pre-ignition and runaway combustion caused by hot deposits Stupid Internal Combustion labs..

CRX Toad

Out with it you already opened up the can of worms....

lil vin

i use 91 in my 91 crx, it has a dohc zc swap in it.....> but u could stick with 87

CRX Toad

Why?

Black4thgenEF

Because he has "too much" money. That is the only thing that I can think of.

hushypushy

My 95 EX came with a D16Z6. I used to run 87 all the time, and the first time I put 89 in I swear to Solid Snake that VTEC was much stronger. In the next few tanks I went back and forth between 87 and 89 and felt......no difference. I think something was wrong with the VTEC in that car anyway.

In my 91 Si, with a SOHC ZC, on this last tank I filled up with 89 as opposed to 87. At the beginning of the tank, I was getting a lot of pinging...and now, my car just feels sluggish. I'll be going with 87 from now on.

Mr.Death

Why feed it wine while grape juice will do just fine. 87 no more.

b20vtech

y 87? when 91 is under 2 bucks?

Got_soy

87, because thats what the STOCK timing maps on your STOCK Z6 were developed for

gibsanez

hushypushy

Your logic is flawed.

1. 91 won't do anything good for a stock Z6
2. It doesn't matter if 91 was $1/gallon, 87 is still going to be cheaper.

specialized108

e85?
just wanted to bring another bad option into the mix....
def just go with 87

dr_latino999

In summation, excess combustion chamber deposits do a couple of things.

1 - Decrease the volume in the combustion chamber. It may not look like much but that film of carbon on top of your piston and elsewhere like the valve faces is subtracting from the volume of the chamber, hence forth increasing compression slightly.

2 - Surface ignition. The carbon deposits have different thermal properties than the surrounding piston and cylinder walls. As such, the intake charge of fuel and air may ignite prematurely on these hot deposits. This was seen with older cars where you would turn the ignition off and yet the engine would still continue to fire.

3 - Self ignition. The pressure and the temperature of the unburnt gases are such as to cause spontaneous ignition, which we know as knock. When knock occurs, you lose the thermal boundary at the combustion chamber walls. Heat transfer than increases which leads to pre-ignition. If it occurs early in the compression stroke, the spontaneous ignition will occur earlier and lead to more severe knock. This in turn makes the pre-ignition even earlier, and leads to a situation known as run-away knock. This will cause overheating of the piston.

xsirenax

if you run a higher octane on the car when it doesnt need it....youll actually get crappy fuel mileage too

just stick to the 87

ponchdriver16

87 douche

dacrxguy

i bet op wants to use 91 w/ octane booster

ComeOnKip

I lol'd. This forums going to hell in a handbasket. Thanks ib.

CRX Toad

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