[FlukeSS]

Discovered something interesting...

So my car is flex fuel tuned for E85.

It seems when I run E85, no snap crackle pop.

I've since switched back to 93 pump for the winter, and suddenly snap crackle pop cereal all over the place!

[arpad_m]

Just a guess, but maybe the flex fuel spark tables command an advance delta with high ethanol that reduces the pop/crackle effect of the minimum final spark table.

[ember1205]

Originally Posted by arpad_m

Just a guess, but maybe the flex fuel spark tables command an advance delta with high ethanol that reduces the pop/crackle effect of the minimum final spark table.

Since GM purposefully added the extra fuel "dumping" on pump gas, I would expect that it would need to be factored in for E85 use as well... Otherwise, the car will actually run correctly.

[Gunkk]

Tuner probably was all about business and not bothered to waste time figuring out twenty-three dimensions worth of spark table playtoy stuff.

[ctrlz]

Originally Posted by ember1205

Otherwise, the car will actually run correctly.

Sacrilege!

[Aragorn]

Originally Posted by FlukeSS

Discovered something interesting...

So my car is flex fuel tuned for E85.

It seems when I run E85, no snap crackle pop.

I've since switched back to 93 pump for the winter, and suddenly snap crackle pop cereal all over the place!

Every tuned Camaro that I have seen loses that with E 85.

[FlukeSS]

Originally Posted by arpad_m

Just a guess, but maybe the flex fuel spark tables command an advance delta with high ethanol that reduces the pop/crackle effect of the minimum final spark table.

Great! Now in english?

[6spdhyperblue]

Originally Posted by arpad_m

Just a guess, but maybe the flex fuel spark tables command an advance delta with high ethanol that reduces the pop/crackle effect of the minimum final spark table.

Bingo -

Look at the flex fuel truck E timing map for the top four rows, it’s negative values

My car sounds the same on E as 93.
It’s doable

[FlukeSS]

Originally Posted by 6spdhyperblue

Bingo -

Look at the flex fuel truck E timing map for the top four rows, it’s negative values

My car sounds the same on E as 93.
It’s doable

So does this technically mean, some gas is being thrown out the exhaust pipe, cuz, $5.20/gallon is a valid reason to remove the snap crackle pops.

I've never been a nerd of the snap crack pops anyways. I don't think it sounds good unlike some people lol To me it sounds like the car is mis-tuned.

[ember1205]

Originally Posted by FlukeSS

So does this technically mean, some gas is being thrown out the exhaust pipe, cuz, $5.20/gallon is a valid reason to remove the snap crackle pops.

I've never been a nerd of the snap crack pops anyways. I don't think it sounds good unlike some people lol To me it sounds like the car is mis-tuned.

It -is- "mis-tuned." That's why a tune for a fuel change or similar results in it going away - the car is actually tuned to run properly.

[SATINSTEEL1LE]

Originally Posted by ember1205

It -is- "mis-tuned." That's why a tune for a fuel change or similar results in it going away - the car is actually tuned to run properly.

This is such an uninformed idiotic internet facts post if I've ever seen one...LOL People like you vote and drive and make babies and it scares the hell out of me.

Meanwhile on planet earth whats pictured below is the portion of your factory tune where the burbles, pops and bangs are setup and managed. And can be enabled or disabled with those values as you(your tuner) sees fit.

[ember1205]

Originally Posted by SATINSTEEL1LE

This is such an uninformed idiotic internet facts post if I've ever seen one...LOL People like you vote and drive and make babies and it scares the hell out of me.

Meanwhile on planet earth whats pictured below is the portion of your factory tune where the burbles, pops and bangs are setup and managed. And can be enabled or disabled in with those values as you(your tuner) sees fit.

Thank you for the insults and then proving me right.

The tune from the factory is purposely done to push extra fuel into the system so that on deceleration it causes the system to burn it off and make these sounds. The only way to remove the tune that causes these sounds is to tune the engine to "run correctly."

"Mis-tuned" and "running correctly" are not things that are explicitly defined with specific parameters and should be seen as generalizations - hence why I have quoted them. The sounds being generated are on purpose, from the manufacturer, and will constitute a proper tune according to what they intended to achieve.

[SATINSTEEL1LE]

Here's a great video also showing how to setup a burble tune.

[SATINSTEEL1LE]

Originally Posted by ember1205

Thank you for the insults and then proving me right.

The tune from the factory is purposely done to push extra fuel into the system so that on deceleration it causes the system to burn it off and make these sounds. The only way to remove the tune that causes these sounds is to tune the engine to "run correctly."

"Mis-tuned" and "running correctly" are not things that are explicitly defined with specific parameters and should be seen as generalizations - hence why I have quoted them. The sounds being generated are on purpose, from the manufacturer, and will constitute a proper tune according to what they intended to achieve.

Nobody proved you right. The car can do the burbles without being "mistuned". Please dont think you are correct here. The burble tuning is a novelty meant to make the car sound more aggressive. And in no way are you mistuning the car to make this happen.