my tuned GTI suffered a catastrophic engine failure...

[Keehs360]

In regards to detonation/knock and running a 91 tune with 93 fuel:

Correct me if I'm wrong, but doesn't a higher octane basically allow for greater compression without detonation (the igniting of fuel in cylinder based on compression and heat BEFORE the spark plug is supposed to ignite it)? By that regard, by running the higher "unnecessary" octane, you are giving the engine a greater safety margin?

On the contrary, diesel motors do rely on detonation for ignition as they do not have spark plugs.

Am I on the right track?

In regards to running a 91 tune with 93 octane. You can argue that you have a type of safety blanket, sure. The real gain will be the fact that you can beat it longer before she starts pulling timing and or boost. I’m not sure if the ea888 also pulls boost.

fa20 wrx’s on a 91 tune running 93 octane have interesting logs. The car’s dam fbk and fkl are steady as you’d expect but at wot the car advances all the timing it possibly can that the 91 octane tune would allow.

 

[Hollywood0220]

In regards to running a 91 tune with 93 octane. You can argue that you have a type of safety blanket, sure. The real gain will be the fact that you can beat it longer before she starts pulling timing and or boost. I’m not sure if the ea888 also pulls boost.

fa20 wrx’s on a 91 tune running 93 octane have interesting logs. The car’s dam fbk and fkl are steady as you’d expect but at wot the car advances all the timing it possibly can that the 91 octane tune would allow.

No more "guess" work Keehs360.
This is not how it works. You are trying to understand it, but expressing it as if you do.

 

[Keehs360]

No more "guess" work Keehs360.
This is not how it works. You are trying to understand it, but expressing it as if you do.

I didn’t take any guesses at all. Stop harassing me.

running two octane points higher will allow you to stress the motor longer. Without it yanking timing or boost. That’s a fact.

stop harassing me

 

[Hollywood0220]

I didn’t take any guesses at all. Stop harassing me.

running two octane points higher will allow you to stress the motor longer. Without it yanking timing or boost. That’s a fact.

stop harassing me

Discourse in a public forum isn't harrassment bud. You can stop that barracks lawyer nonsense.

Higher Octane Fuel = Increased Knock Threshold
IAT will dictate the combustion and in return the ECU will adjust (timing and/or boost) to match BOTH In/Out measurements.

Octane isn't keeping timing or boost - you have it completely wrong bud.

 

[GTIfan99]

Discourse in a public forum isn't harrassment bud. You can stop that barracks lawyer nonsense.

Higher Octane Fuel = Increased Knock Threshold
IAT will dictate the combustion and in return the ECU will adjust (timing and/or boost) to match BOTH In/Out measurements.

Octane isn't keeping timing or boost - you have it completely wrong bud.

Are you claiming increased knock won't cause the ECU to pull timing and or boost?

 

[cb1111]

Higher octane isn't always better. It really depends on how the car is tuned.

From the article when cars that expected regular were fed higher octane:

"Our low-tech Ram managed to eke out a few extra dyno ponies on premium fuel, but at the track its performance was virtually identical. The Mustang's knock sensors and EEC-V computer found 2 hp more on the dyno and shaved a more impressive 0.3 second off its quarter-mile time at the track. The Accord took a tiny step backward in power (minus 2.6 percent) and performance (minus 1.5 percent) on premium fuel"

 

[GTIfan99]

A study about running 93 octane in cars designed for 87 Oct in stock NA cars is hardly relevant here.

 

[STL11]

Compared to running the 93 tune, a 91 tune on 93 would be slightly more expensive gas for a little less power. Not as "drastic" as described but still a sacrifice in some eyes.

Gas here in NC is 87/89/93, so it’s not really added extra expense.

 

[Keehs360]

Higher octane isn't always better. It really depends on how the car is tuned.

From the article when cars that expected regular were fed higher octane:

"Our low-tech Ram managed to eke out a few extra dyno ponies on premium fuel, but at the track its performance was virtually identical. The Mustang's knock sensors and EEC-V computer found 2 hp more on the dyno and shaved a more impressive 0.3 second off its quarter-mile time at the track. The Accord took a tiny step backward in power (minus 2.6 percent) and performance (minus 1.5 percent) on premium fuel"

For some reason a lot of it has to do with how sensitive knock sensors are on your car.

Subaru’s are noisy engines. It’s common to desensitize the sensors at lower ranges after a tune. the wrx isn’t the gti but bare with me; the sensors are by far the most sensitive sensors ever. In fact a stock wrx will stop pulling timing if you add 2-3 gallons of e85 to a tank full of premium fuel. Ron from Phatbotti has all that data on his site.

when driving the gti (stock) I’ve never felt it yank timing at all. All it took was two laps at my favorite canyon road and the heat soak definitely let me feel the gti pull timing. It wasn’t too pronounced but it was there.

a stage 1 91 octane gti would obviously benefit from 93 octane fuel when pushing her hard.

 

[Keehs360]

A study about running 93 octane in cars designed for 87 Oct in stock NA cars is hardly relevant here.

Unless said na car that was blessed with the higher octane is being pushed crazy hard?

but yeah I see what you’re saying.

 

[Hollywood0220]

My masters in engineering, 9 years on 2 gm ecotec teams, and eternity on many private teams says so

do yourself a favor. Don’t try to offer unsolicited advice.If one asks a question, that’s one thing. I don’t know the ea888 platform. I really am just now getting my feet wet. And I am grateful to the folks here who always answer my questions.

your not going to be more knowledgeable than everyone here. And neither will I. I assure you, if I’m curious about something I know how to search. And if that doesn’t work I’ll ask.

you’re very presumptuous and that is very unbecoming

Brother, whatever you think you achieved in the military (and with a Master's no doubt) surely isn't becoming of the way you write.
At least in my Masters program, it was required to write effectively.
Further more, having been in the "Military" (whenever that was) - you surely were not an Officer and never needed to write.
Now, continue soldiering on and I will continue being just as I am.

 

[Keehs360]

Brother, whatever you think you achieved in the military (and with a Master's no doubt) surely isn't becoming of the way your write.
At least in my Masters program, it was required to write effectively.
Further more, having been in the "Military" (whenever that was) - you surely were not an Officer and never needed to write.
Now, continue soldiering on and I will continue being just as I am.

I wasn’t an officer, I worked for a living.

stop harassing me.

 

[GTIfan99]

Brother, whatever you think you achieved in the military (and with a Master's no doubt) surely isn't becoming of the way you write.
At least in my Masters program, it was required to write effectively.
Further more, having been in the "Military" (whenever that was) - you surely were not an Officer and never needed to write.
Now, continue soldiering on and I will continue being just as I am.

I was an officer, Mustang at that, and have a masters, but I'll let you in on a secret...

This is a car forum, not a thesis.

Thank you for coming to my TED talk.

 

[Diggs24]

The ignore function works wonders.

 

[Keehs360]

The ignore function works wonders.

Oh damn. Thanks, didn’t know that was a thing