scoobyc

iTrader: (2)

So then. What is Det and How does it Damage the engine?

I have done a quick search but not found anything simple enough for me to understand?

Im thinking. Ignition should happen at max compression. Using a lesser fuel will mean a slower ignition, and so produce less power. But im confused as how this will damage the engine?

Is it the case that the ecu will ignite before the piston reaches the top so you get max power. Which will overstress the bearings. as it partially decelerates the piston on the up stroke, so the max explosiveness happens at max compression?

I really have no idea .

scoobyc

iTrader: (2)

Right then. It seems the excessive heat build up during track use causes excessivly aggressive explosions. Damaging the engine.

I read this can be controlled by using high ron fuel. but im unsure as to why this will cure this problem. Will keep searching.

GazTheHat

Engine knocking - Wikipedia, the free encyclopedia

STiFreak

iTrader: (4)

Here is how I understand it:

Ideally you want peak combustion pressure to occur just after TDC (top dead centre), so that all the force is pushing down on the piston.
If ignition happens too early and peak pressure occurs before the piston reaches the top of it's stroke, the force is working against the engine, thereby putting your bearings and other components under huge stress.

If the fuel mixture pre-ignites in the cylinder (due to excessive cylinder temps for example) when this flame collides with the flame front from the spark ignition, they will result in an explosion (detonation).

Higher octane fuels actually burn more slowly and consistently, therefore allowing more spark advance and combustion forces pushing down on your piston for a longer period of time increasing torque.

EDIT: Took too long to reply, Gaz's post has a better overall explanation

flat4 to the floor

thanks buddy i have often wondered exactly what it is,

scoobyc

iTrader: (2)

Sweet.

So high temps causes preignition as it would which is det. The slower burning higher octane causes that inital burning due to higher temps not happen, or happen slow/later reducing the ware.

So does higer ron fuel have a high calorific value. I.e. It burns slow, but it burns more. I.e. expands more, i.e. produces more power?

Ive not read the link yet. ill read it now.

So how will mods like a decat cause det? Surley only if boost is increase? If anything the quicker exhaust should reduce temp and so reduce preignition and so reduce det?