97 or 99

[Bubble]

DET = "Detonation", or "knock", or "the old fashioned term "pinking". The correct term is "pre-ignition"

It is when the inlet charge detonates generaly before the spark plug fires and is a killer for standard pistons. It is caused by over advanved ignition timing, excessive heat, too lean a mixture, or too low an octane fuel amongst others.

Basically.......DET is bad.........very bad........'tis like the devil

[legrat]

s**t you mean worse than my mrs guess i will go back to 99 till i get it remapped cheers mate

[Bubble]

I bet you have nightmares about DET now

[legrat]

nightmares not sure what worse sleeping with mrs tonight or listening out tommorrow for dreaded pinking driving to seething

[Richf]

Originally Posted by Bubble

DET = "Detonation", or "knock", or "the old fashioned term "pinking". The correct term is "pre-ignition"

It is when the inlet charge detonates generaly before the spark plug fires and is a killer for standard pistons. It is caused by over advanved ignition timing, excessive heat, too lean a mixture, or too low an octane fuel amongst others.

Basically.......DET is bad.........very bad........'tis like the devil

Detonation and pre-ignition are different

Detonation or ping is caused by pressure

Pinking or pre-ignition is caused by heat

Cut and paste

Racing and Trackday Fuels - Trackpedia

Knock - Detonation - Ping

Intense pressure within the cylinder due to inability of fuel to have a controlled burn. This could be caused by too low of an octane fuel for the application, poor combustion chamber/squish design, or incorrect timing procedures. The sound you hear is from the actual vibration of the cylinder walls or the fuel exploding micro seconds prior to timed ignition firing which may cause two intense high pressure waves to collide or clap together and the colliding energy wave produces the sound you hear. This is hard on an engine. It is just like taking a ball peen hammer to the pistons. Use of proper fuel and tuning techniques will control this situation.

Note that running an engine lean will NOT cause it to detonate. Many performance engines are set too rich, with far too much ignition advance. This causes longer ignition delay (see above). Then, when the mixture is set less rich (though not yet "lean"), the ignition delay shortens appreciably, resulting in peak pressure far too early. This may result in detonation, if the octane is insufficient for these conditions.


Pre - Ignition

Pre-ignition is the premature ignition or lighting of the mixture in the cylinder. This condition takes place prior to the spark plug firing. It is usually caused by a deposit or object glowing in the combustion chamber. A overheated spark plug or incorrect tuning parameters can cause preignition. This condition occurs while the piston is traveling up during the compression cycle. Pre-ignition may cause the piston to attempt to change directions which can cause major mechanical damage within the engine. Pre-ignition is much different that detonation although they both can reak havock on your engine.

Pre-igntion is a special case of auto-ignition. Auto-ignition occurs in many engines, though we do not realize it, because the auto-ignition point is after the spark plug firing point. Diesel engines depend upon auto-igntion. Ever found your spark ignition (SI) engines continues running even though the igntion is turned off? That's autoignition.

[Jay]

Originally Posted by Richf

Pre-igntion is a special case of auto-ignition. Auto-ignition occurs in many engines, though we do not realize it, because the auto-ignition point is after the spark plug firing point. Diesel engines depend upon auto-igntion. Ever found your spark ignition (SI) engines continues running even though the igntion is turned off? That's autoignition.

Both my old Hilux`s did that, you`d turn the key to shut it off, it`d stay running, often backwards. Sometimes it was a case of stalling it to get it to stop. Never had any problems with it though and it`s still running now.

[legrat]

Originally Posted by Richf

Detonation and pre-ignition are different

Detonation or ping is caused by pressure

Pinking or pre-ignition is caused by heat

Cut and paste

Racing and Trackday Fuels - Trackpedia

Knock - Detonation - Ping

Intense pressure within the cylinder due to inability of fuel to have a controlled burn. This could be caused by too low of an octane fuel for the application, poor combustion chamber/squish design, or incorrect timing procedures. The sound you hear is from the actual vibration of the cylinder walls or the fuel exploding micro seconds prior to timed ignition firing which may cause two intense high pressure waves to collide or clap together and the colliding energy wave produces the sound you hear. This is hard on an engine. It is just like taking a ball peen hammer to the pistons. Use of proper fuel and tuning techniques will control this situation.

Note that running an engine lean will NOT cause it to detonate. Many performance engines are set too rich, with far too much ignition advance. This causes longer ignition delay (see above). Then, when the mixture is set less rich (though not yet "lean"), the ignition delay shortens appreciably, resulting in peak pressure far too early. This may result in detonation, if the octane is insufficient for these conditions.


Pre - Ignition

Pre-ignition is the premature ignition or lighting of the mixture in the cylinder. This condition takes place prior to the spark plug firing. It is usually caused by a deposit or object glowing in the combustion chamber. A overheated spark plug or incorrect tuning parameters can cause preignition. This condition occurs while the piston is traveling up during the compression cycle. Pre-ignition may cause the piston to attempt to change directions which can cause major mechanical damage within the engine. Pre-ignition is much different that detonation although they both can reak havock on your engine.

Pre-igntion is a special case of auto-ignition. Auto-ignition occurs in many engines, though we do not realize it, because the auto-ignition point is after the spark plug firing point. Diesel engines depend upon auto-igntion. Ever found your spark ignition (SI) engines continues running even though the igntion is turned off? That's autoignition.

bloody hell you lot got to go bed soon as up at 4 and have to sleep with the wife and you fill me full of all this will have nightmares all night now
so guess ok to carry on with what i have in tank but next time fill up with 99?

[Richf]

Originally Posted by Jay

Both my old Hilux`s did that, you`d turn the key to shut it off, it`d stay running, often backwards. Sometimes it was a case of stalling it to get it to stop. Never had any problems with it though and it`s still running now.

Most old Fords used to run on a little , i once saw someone pull up and refill his Cortina, go in a pay and come out and it was still coughing and chugging away

Fuel is better and more importantly engine management systems have made this a thing of the past , very rarely do you need to de-coke an engine nowadays.

[Richf]

Legrat

Dont worry too much about it , if the car feels right and isnt making any unusual noise then its probably ok.

The Skyline has two knock sensors on the engine , basically microphones and any noise in the frequency of detonation will be interpreted by the ECU as knock and the ignition retarded to compensate, as Jay said the stock ecu is more than capable of looking after things , the downside of course is by backing or retarding the ignition the engine will produce less power and use more fuel

[legrat]

cheers rich just done 300 miles today and still a quarter of a tank left so i think there is no obvious problems as power there when i needed it

[skyliner08]

ray yeah ive seen that ad it does show 97ron