Puff Of Brown Smoke When Cracking It.....

[ashmo]

not to sound like a noob but what is "pinging" exactly? I know what detonation is but dont know what pinging is?

[FastR1Red]

I thought you meant puff of brown smoke with crack.

Didn't know you could smoke the stuff.

Only in America.

[XF Falcon]

I thought pinging and detonation is the same thing. I always refer to the sound of detonation as pinging if I talk to someone.

EDIT: I could be wrong though! hehe

Edited 04/09/07 04:29 AM by XF Falcon

[ashmo]

now it makes sense, cheers mate

[Guest FatBAt]

I thought excessive fuel was grey to black smoke. Never known it to be brown.

[Guest FatBAt]

I thought pinging and detonation is the same thing. I always refer to the sound of detonation as pinging if I talk to someone.

EDIT: I could be wrong though! hehe

You're 90% right. Pinging is caused by PRE detonation. Every car has detonation.....otherwise it wouldn't go.

Cheers

[BFHOON]

hope this helps......

Detonation/pinging creates extremely violent combustion shock loadings, as the actual combustion process is completely transformed in nature from normal combustion.

The easiest way to explain the differences between "normal combustion" and "detonation combustion" is to imagine a small amount of petrol is poured along a flat surface, and then lit. When it is ignited the flame runs along the line of poured fuel, gradually lighting it all along the way. This is how "normal combustion" takes place in the engine. The air/fuel mix is ignited by the ignition source and the resultant flame propagates across the combustion chamber, consuming most of the fuel/air mix along the way. Combustion pressure pushes the piston in a downward motion and this vertical movement is turned into rotating motion by the conrod and crankshaft.

By comparison, "detonation combustion" is like an instantaneous explosion in the combustion chamber, rather than a controlled burn that builds cylinder pressure gradually. The explosion is like dynamite going off in the cylinder, with huge cylinder pressures blasting out in all directions at once. Everything in the combustion chamber is smashed into by this force, cracking pistons, hammering the piston rings, shattering spark plugs and, in the case of XR6-Turbos, bending/breaking the conrods.

[Headsex]

First of all, lets forget about smoke colour as everyone has difference opinion abouyt the shade of black or grey

When tuning these xr6t, tuners increase the boost and all of a sudden the enrichment is increased due to the rate in change of air mass whilst the turbo comes on boost. This is why a std xr6t doesn't do it.

With my plenum, I had to make alterations so it doesn't do it as much, because it seemed to do it a lot more then it did compared to other cars without plenums.

There are also tuners which max out the fuel tip in value so essentially the fuel is pissing out the injectors with any change of the throttle position. This is pointless practice, and trying to stop the engine detonationing because they have too much timing there to begin with.

Air fuel ratio does not make any difference to stopping a car pinging, it varies the amount of timing a engine can tollerate. What I found during the nizpro dyno demonstration is that people tuning in the 10's or 11's afrs are wasting their time, and torque the engine can produce.

On a standard xr6 turbo calibration, at 5000rpm, and 5psi boost, it can tollerate approx 16degrees(don't quote me, I'm not infront of my pc) timing at 14.7afr

At .7 lambda, 10.29:1 afr, you can add another 10 odd degrees timing.

Now the interesting part, at 1.4 lambda, approx 20.5:1 afr, it can also add about another 10 to 12 degrees timing..

This is based on a adder table to spark based on air fuel ratio...

Most tuners zero this table out... meaning it will either be too much timing at 14.7afr, or not enough timing at 12.0afr...

heck, even I'm guilty on this as I based my original tuners using the capa generic files as a base (I bet every tuner did), my current files now that I use are drastically different to how things are done now, and are based closer to a engineering standpoint, ie, how ford would have done it.

But without having a engine dyno in a controlled environment, its very hard to adjust things like air temp corrections, so my opinion is that, ford did it in a controlled environment, so don't touch their values.

Now to the point of the smoke out of the exhaust. 3 things cause this generally.

1) oil, usually blueish

2) fuel, blackish (enrichment, ie jumping on the pedal)

3) detonation/ping, blackish "pop"

Those who whitnessed me tuning at marios would have seen the pops I was talking about(I told them to look for it, as its usally happens on the point where the ping is audiable), usually around 4500rpm at peak torque when they are most suspectable to detonate. It gives a small pop out of the exhaust, usually blackish in colour.

If your behind someone who's at wot, espeially a auto when they are less likely to lift off the pedal, and notice a pop of smoke, then that's definatly detonation/ping.

D.

[ENVY-T]

So in other words, some people are pissing fuel away, that could be used for far better purposes, like, um, making power and torque?

[Headsex]

So in other words, some people are pissing fuel away, that could be used for far better purposes, like, um, making power and torque?

Yeh, and more importantly, fuel economy.

Imagine crusing at 100km/h and a small transision in the throttle and it uses 10 times the amount of fuel needed.. This is what happens when you change the fuel tip in from 0.1 to 1.0

There is also another main value which alters the fuel enrichment, but that ones gonna be kept a secret