Saprissa

Here is a rockintunes/nicedeboy classic, regarding Bi-X installation:

nlpamg

so c230_217, are you going to delete this thread too?

from190e_cs

Saprissa

he could.... i don't think he cares though...
he's got about another 3 or 4 aliases running on MBWorld as we speak.

He accumulates posts (in CLK, off topic, etc... threads) to make himself look legit, but in time the brain damage kicks in, and he exposes himself without even trying. Pathetic loser.

nlpamg

Smart, too bad almost all of the people that are subscribed to this thread got it before you had a chance to edit it out. Thanks for admitting it. If you don't know who c230_617 is, then why did you delete your previous thread about stickers?

from190e_cs

Man this thread is off topic. Please focus on the topics not other nonsense about who is who. WHO CARES.

Saprissa

why do you delete all your threads ?
Including your "Duplicate Thread" of JimBanville's carbon fiber sticky interior ?

hmmmm, where have I heard that exact complaint before ???

do us all a favor and delete this one too !!

nlpamg

dude, you've been banned at least 20 times already and yet you still keep coming back. can't you tell or see that you're clearly not wanted? get your ghetto *** out of here.

Maestro

Yep. We get 91, they get 94.

Saprissa

that really sucks. I would use 93 or 94 if available.
Would have RENNtech reprogram my ECU accordingly.
I do know that there are some UNOCAL or UNION 76, or whatever they're called nowadays, that sell some really high octane up in Los Angeles. It was in the high 90's (97/98)

from190e_cs

Yeah I seen 110

E55AMG99

More like 100.

Outland

He was referring to the number of times he's been banned, not octane numbers.

straightSIX

Using low octane gas causes premature cat failure.

tuscanraider

Here in Jersey, especially around the Shore, older muscle cars are very popular. Lots of guys run CAM 2, ie. Sunoco Race Fuel. I don't think it would be good for the imports though.

"Cam 2" is the generic name used for Sunoco Race Fuels. You can expect the same consistent high quality performance from Cam 2 Racing Gasoline that you get from Sunoco Race Fuels because the names are interchangeable. It is the same product, made in the same facility by the same people. We use this name wherever the "Sunoco" brand name cannot be used, such as gasoline outlets which carry a competing brand of street gasoline. Cam 2 is available in 110, 112, and 116 octane leaded, and 100 and 104 unleaded.

E55AMG99

Another load of BS! Where did you go to school?

mctwin2kman

Well lets put it this way. The ECU is set to use a certain Octane Fuel. Diferent Octane Fuel's combust at diferent times, that is that a lower one will burn before a higher one. So you would actually have combustion occure before it was intended by using the lowe octane fuel. Therefore making combustion less efficient than it is supposed to be! Also you would cause excessive detonation, aka Ping, which can in the long run damage the engine. By damage I mean you may just put a hole in the top of a piston! In order for the ECU to back off timing to correct for pre-mature detonation it needs to first sense it. So assuming that the ECU will handle it is just plain wrong since it has to detect it to correct for it.

Spyke

Nope. Under the same pressure/temp, a lower octane gasoline detonates before a higher octane gasoline. It has nothing to do with when combustion begins - the spark plug controls that. Or at least it should. If it doesn't, you have problems that higher octane gas won't fix.

Narcissus

Your car will run fine at 87 and it should not damage the engine, the ECU will adapt and pre-ignite to prevent pinging, but you will lose a lot of power and greatly affect your mileage, so you'll end up paying more for the ammount of miles you'll drive once the tank is empty.


We have 87-89-91-94 here up north as well.

Outland

I had the misfortune of having to put 87 octane in my bike the other night...I had run over to a friends place, didn't have anything but a fiver in my pocket.

Never again...thing pinged like mad the last couple of days, especially in the heat.

mctwin2kman

The ECU has to sense the Ping in order to retard the spark and timing. So no it is not OK to run lower Octane, especially in the C230K since it will cause detonation. I have no idea why no one understands that there has to be a Knock in order for the Knock Sensor to detect it. Thus if the ECU is reatarding then the damage is already being done. AAA actually did a story on this for our local news. Causes more damage to run lesser octane than required. Sorry to burst your bubble but it will hurt the engine in the long run.

mctwin2kman

If it does not Combust when it is supposed to then it is bad. The engine and ignition system is designed for certain octane. Therefore if you have Pre-Detonation due to Regular Gas igniting before it is supposed to then you have a problem!

E55AMG99

What you are saying is mostly true except that fuels of differing octane ratings do not burn at different rates. This is a myth. Higher octane rated fuels resist pre-ignition and detonation (two different terms and two different problems) because their self igniting point is at a higher temperature and pressure.


The poor engine performance caused by the use of low octane fuel will not cause catalytic converter damage. The combustion process is still completed except that there is an uncontrolled secondary ignition source. It will, as you said, cause other major engine problems like burned pistons, broken rings, etc.

E55AMG99

True, there has to be a knock before the ECU can react. However, it is a false assumption that the amount of knocking that occurs prior to the ECU remapping engine parameters to combat it will be enough to cause damage. The sensors and ECU react in milliseconds. Most engine builders agree that light knocking is OK and will not casue any problems.

Spyke

One of the problems in these discussions is terminology. To me, if the mixture doesn't combust when it is supposed to you have a mis-fire. If it ignites before it is supposed to, you have pre-ignition. The octane rating of the gas isn't relevant to either. I have no idea what people mean by "pre-detonation"? There is pre-ignition, and there is detonation, but they are different events. "Pre-detonation" would seem to apply to the period before detonation occurs, which would in most cases mean normal combustion.

Anyway, pre-ignition is caused by a hot spot in the cylinder igniting the mixture before the plug fires. It is caused by a physical fault in the combustion chamber; a sharp edge, an exposed thread on the plug, a carbon deposit, whatever. You really need to address this fault to fix the problem, going to a higher octane gas isn't the correct answer here.

Detonation occurs when the unburned mixture in the cylinder auto-ignites/explodes/detonates as a result of the temp and pressure in the cylinder. There are numerous ways to fight this, one of them being using a gas that resists detonation longer, i.e. has a higher octane rating.

Pre-ignition may lead to detonation, but they are not the same thing. You can have one without the other.

EDIT: I re-read some of the replies here and I'm wondering if some people aren't envisioning a running engine as a series of explosions in the cylinders? That's not what's going on. In normal combustion, there is a flame front. The fuel actually does burn (rapidly) rather than explode. When the mixture detonates, the is no flame front, just BOOM. Many engine texts have pictures of normal combustion vs detonation - you can easily see the difference.

Regarding an earlier post - not only does light knock not harm an engine, it can actually increase power. I think VW published an SAE paper on this back in the late '70s, early '80s??? The problem is, who defines what "light" knock is, and how do you control it so it never becomes not-so-light knock?