Knock With Stock Ecu

[tmc_2]

Hi guys,

I want to know if your standard ECU gives u any warning if it detects high knock levels?

My first r33 dusted it self in one nght due to exesive knock. At the time the mechanic had sorted out the misfiring and th eonly symptoms i had left where the slight matchbox ratle sound that u couldnt really hear. I had no idea that this was the sound of knock. Fast foward 2 years and on my seccond newly aquired r33.

I am rather paranoid about knock. I have a SAFC neo but i am reluctant to bother tuning it as it has no knock readout.

Do you guys think i shoudl get some sort of knock readout or bte the bullet for a PFC.

Is there a cheaper way than a PFC?

Cheers

[paulr33]

stock ecu will not let you know of knocking, it will just carry on in the background and drop to the low octane map when it picks up enough knocking.

[tmc_2]

stock ecu will not let you know of knocking, it will just carry on in the background and drop to the low octane map when it picks up enough knocking.

So even tho it drops the map it still cannot protect u from blowing ur motoer for sure.

And it has no driver warning if this happens.

Is this a similar map to R&R there for experience the same power loss?

[paulr33]

once it picks up enough knocking to activate the low octane map mode it drops to the lower octane map. basically it see's knocking and assumes youve put in penis fuel (95ron or lower) so it drops to the low map.

the low map is really retarded timing, so it would negate any knocking you were seeing. the timing would be really really retardard, the car will work, it will just be boggy and sluggish i would expect

i am unsure if r&r is a map change (i dont think it is) once the ramp is triggered it activates r&r which is probably a quick negative adjust to timing to the whole map and richen up by a precentage on the inj map

both i think are temproary (say 4 seconds of it) and then it backs off, well it could be 4 seconds or it may until the afm signal drops again

[tmc_2]

once it picks up enough knocking to activate the low octane map mode it drops to the lower octane map. basically it see's knocking and assumes youve put in penis fuel (95ron or lower) so it drops to the low map.

the low map is really retarded timing, so it would negate any knocking you were seeing. the timing would be really really retardard, the car will work, it will just be boggy and sluggish i would expect

i am unsure if r&r is a map change (i dont think it is) once the ramp is triggered it activates r&r which is probably a quick negative adjust to timing to the whole map and richen up by a precentage on the inj map

both i think are temproary (say 4 seconds of it) and then it backs off, well it could be 4 seconds or it may until the afm signal drops again

That all soudns very logical,

I dont understand then how i dusted a piston in my first r33 running 9psi of boost. I know it was pining but it it had stock ecu and 98ron fuel the ecu wold drop map and it should have saved it self???? shouldnt it?

I am concerned wiht my current r33 as the dyno turner has given it 25degree advance timming, he says the car just doesnt wan tot do any hting on normal base timing for some reason.

ITs getting tuned again this weekend as i am concere dit may not be safe, some times it get sluggish and other times run ok, i reduced boost from 10 psi to about 8-9 psi but it still experiences the inconsistent performance.

[WogsRus]

pinging is a lot worse then knocking, so that's propably why the car died. I have an SAFCII and it's whows up knock, i see as high as 30 sometimes when the car has been sitting in the sun olday and then i go to drive it, but after 5 minuts after i swich it off, it returns back to 10 or so. My car goes much better with the knock at 10 then it does at 0.

[tmc_2]

pinging is a lot worse then knocking, so that's propably why the car died. I have an SAFCII and it's whows up knock, i see as high as 30 sometimes when the car has been sitting in the sun olday and then i go to drive it, but after 5 minuts after i swich it off, it returns back to 10 or so. My car goes much better with the knock at 10 then it does at 0.

Pining/knocking? i know them to be the same thing i may be wrong.

I have a safc neo i purchased but hte damn thing doesnt have a knock read out. Does any one know of a wire mode for the neo so i can read nock or any other aftermarlet knock gauges?

Thanks.

[WogsRus]

ok here you go.

Pinging or Pre_Ignition

Pre-ignition is a different phenomenon from detonation, explained above, and occurs when the air/fuel mixture in the cylinder (or even just entering the cylinder) ignites before the spark plug fires. Pre-ignition is caused by an ignition source other than the spark. Heat or hot spots can buildup in engine intake or cylinder components due to improper design, for example, spark plugs with heat range too hot for the conditions, or due to carbon deposits in the combustion chamber. Spark plugs with a high heat range will run hot enough to burn off deposits that lead to plug fouling in a worn engine, but the electrode of the plug itself can occasionally heat soak, and begin glowing hot enough to become an uncontrolled ignition source on its own. Bits of carbon that build up in a combustion chamber can also heat soak to the point where they also are glowing hot and ignite the air-fuel mixture before the proper time.

Pre-ignition and "dieseling" or "run on" are the same phenomenon, except in the latter case the engine continues to run after the ignition is shut off with a hot spot as an ignition source. Pre-ignition might cause rough running due to the advanced and erratic effective igniton timing and may cause noise if it leads to detonation. It may also cause "rumble" which is fast and premature but not detonating combustion.

This heat buildup can only be prevented by eliminating the overheating (through redesign or cleaning) or the compression effects (by reducing the load on the engine or temperature of intake air). As such, if pre-ignition is allowed to continue for any length of time, power output and fuel economy is reduced and engine damage may result.

Pre-ignition may lead to detonation and detonation may lead to pre-ignition or either may exist separately.

Knocking or DETONATION

The fuel/air mixture is normally ignited slightly before the point of maximum compression to allow a small time for the flame-front of the burning fuel to expand throughout the mixture so that maximum pressure occurs at the optimum point. The flame-front moves at roughly 33.5 m/second (110 feet/second) during normal combustion. It is only when the remaining unburned mixture is heated and pressurized by the advancing flame front for a certain length of time that the detonation occurs. It is caused by an instantaneous ignition of the remaining fuel/air mixture in the form of an explosion. The cylinder pressure rises dramatically beyond its design limits and if allowed to persist detonation will damage or destroy engine parts.

[tmc_2]

Thanks WogsRus , I ma experiencing knocking/detonation