Regular or Premium Gas?

[Rac3rX]

detonation, like mentioned, refers simple to irregular expansion of the mixture...detonation is only one term describing many different types...autoignition is generaly used to define a form of detonation that occurs when internal heat ignites the mixture...this can cause two or more flame fronts within a cylinder that all collide...and make noise...and hurt things...

Now flash expansion is also a form of detonation, of which the expansion reaction ends relatively quickly...this does not mean it is always bad for power...this occurs very often with near stoich mixtures while load increases...and it is not very hard to control under certain conditions...and can often create more power than otherwise because of the violent expansion...the only bad part is the crown scorching that can occur...because of hot spots...

but that wasn't the point of my original post...I didn't mean to single just you out...I just read your post to Pretzel...so started with that...that is all...

but my point was that an octane rating has nothing to do with how much power your car will make...

In your case for example, you are wasting your money...no offense or anything, but the stock ecu will not change your ignition timing to take advantage of a slower burning fuel...You need to advance the ignition timing before TDC more to offset the fuels slower expansion...your ecu will not do that...and the more stability is not needed for the mods you mentioned, mostly because the compression is still relatively low per high rated fuels stability...and the ecu is very mild on the ignition advance...the increased flow from a couple bolt-ons is nothing as far as the gas is concerned...an increase of cylinder pressure equated into ~15-20hp is rarely enough to need to switch fuel, unless there are some other things going on...

correct me if I am wrong though dude...its your car...if you were having problems with detonation, so be it...but I ran similar bolt-ons with long reach plugs for 40,000 miles on the old engine without any detonation at all...all while using 87 rated...and it ran great...

now if

Great Post, nicely put.

Im over protective of My ride, especially with all the N/A Proteges getting busted rod berings, it cant all be due to oil starvation only....

 

[boostpower]

premiun 93 only (first)

 

[Installshield 2]

Great Post, nicely put.

Im over protective of My ride, especially with all the N/A Proteges getting busted rod berings, it cant all be due to oil starvation only....

that is one thing...It can always be regarded as "safer", at least to a point...plug fouling can occur if the gas is too stable, and carbon build up could also increase...but a stock protege does not need higher rated...a lightly modified one does not either, but it wouldn't really hurt anything...if that little extra comfort of knowing your chances of detonation are even lower is worth a little extra money, thats cool...

I don't know...I think I lost track of my original point altogether...I only wanted to stress that higher rated fuel will not make more power on its own...it just allows an engine to meet conditions of tune and physical compression to make more power...it otherwise wouldn't...but it isn't the fuel that is doing any magic, other than reacting a bit slower...

 

[Installshield 2]

Your telling me I hurt my credibility when saying knock is no good for performance, & reducing it prevent power loss due to knock?

So your saying knock has NO ill impact on performance at all?

I just want to be clear.

No...I was saying that arguing with yourself hurts your own credibility...you were just saying "less detonation means more power" which in certain circumstances is not true......you didn't say "knock" originally, and I refer to audible detonation as just a few of the many types...thats all, no big deal...

 

[icspots]

If I had a million dollars...

If I ruled the world...

There are alot of if's out there.

Im talking about a Modded engine getting more air flow then stock, & being used at levels much more demanding then regular use.

I was going to ask how much power over stock an engine should be trying to make in order for higher octane to actually be needed to keep it running smoothly, but installshield seems to've asked and answered that question far better than I could already.