What Does Detonation Feel Like?

[JD1964]

Consider a turbo or SC application

Consider you have no instruments to tell you about air fuel mixture

What would you feel or hear if detonation happen while driving WOT? Bucking, knocking, noise.....what?

 

[GroverDill]

a rattle mostly

 

[hoopty5.0]

^ this. Like a tic tac rattling around in its box.

 

[CarMichael Angelo]

That's what I hear. It is audible over the engine and its exhaust, but you have to be listening for it. It sounds like something that compares to rattling a wooden dowel between two metal bars.....

Not a good noise.

 

[mikestang63]

expensive

 

[JD1964]

Is there an aftermarket knock sensor setup available for Foxbody 5.0's?

 

[JD1964]

Suppose you have everything right, injector size and all, but one injector fails. One cylinder leans and........what?

We need a knock sensor setup. Whoever can invent a marketable one wins!

 

[JD1964]

Seriously, f*** this seat of the pants crap!

 

[hoopty5.0]

Suppose you have everything right, injector size and all, but one injector fails. One cylinder leans and........what?

We need a knock sensor setup. Whoever can invent a marketable one wins!

What happens is the dead injector will make the AFR go leaner and the computer compensates by squirting more fuel. Hard to tell without an O2 sensor on every primary when this happens.

 

[liljoe07]

Detonation is happening, long before you hear it. Once it's Audible, it's pretty bad.

 

[General karthief]

I going with the thought that on n/a, or even stock with a few mods the eec would catch a lean condition and compensate, its more of a concern with power adders, right?
Do they have them on 96 up models?

 

[Noobz347]

I going with the thought that on n/a, or even stock with a few mods the eec would catch a lean condition and compensate, its more of a concern with power adders, right?
Do they have them on 96 up models?

No. You can blow an N/A car sky high with detonation and at the same time, have detonation on a force inducted car and NOT blow it up.

It's never good, and it's hard on gaskets and internals. Having one kind of setup versus another does not guaranteed that detonation will or won't break parts. Hearing it does not assure that there will be broken parts.

If you hear detonation then it needs to be addressed immediately. With luck, nothing has broken... yet.

Consider you have no instruments to tell you about air fuel mixture

Seriously, f*** this seat of the pants crap!

Wait, wha?

If you put these things you mention into the car, then it would no longer be SOTP. Juss Sayin'.

 

[Mustang5L5]

It sounds like loose cat converter heat shields rattling around. Another way to describe it is a can of BB's being shaken around under your hood.

 

[General karthief]

I agree noobs, I grew up when high compression ruled and gas changed to unleaded. THAT was bad, todays fuel is even worse in places, but with the computer controlled stock vehicles built in the last 20 or even 30 years it's not as catastrophic as it once was, I have seen vehicles that are just a few years old with catastrophic piston failures mostly in suvs and trucks that owners just don't take care of, not like the oil pan evacuations of the past.
This is a brain storming session for the power adder crowed that I am not a member of but I am interested all the same.
So, did ford have a knock sensor and when was it first used?

 

[90sickfox]

Is there an aftermarket knock sensor setup available for Foxbody 5.0's?

The trucks ( f150s ) came with a knock sensor. A lot of 302 blocks have the threads for it behind the passenger side if the intake.

The Megasquirt mspnp2 has an earphone jack that can be used to listen for ping...and there is software to support timing retard when detonation is heard. There is a bit of info floating around. There are mods to put earphone jacks on knock sensors directly...and also ways to wire them to oscilloscopes to watch the frequency variations of your running motor.

 

[srtthis]

expensive

this!!! every time ive heard it nothing good came from it

 

[TOOLOW91]

You just did head gaskets no? Obviously the car needs to get on a dyno and be gone through tune up wise to make sure its ok or i think youre going to be in the same boat again.

Whats the fuel system consist of again?

 

[Mustang5L5]

The trucks ( f150s ) came with a knock sensor. A lot of 302 blocks have the threads for it behind the passenger side if the intake.

Always wondered why the Fox 5.0 never got it. Even the 2.3L's had a knock sensor IIRC

 

[srtthis]

Always wondered why the Fox 5.0 never got it. Even the 2.3L's had a knock sensor IIRC

my guess sensitivity issues with the way us assholes modify these cars

 

[Noobz347]

this!!! every time ive heard it nothing good came from it

One of the theories in that there's too much noise in the drive train between the sensor pickup and both banks of combustion.

Yet another theory was that the EEC-IV was not fast enough to take a sufficient number of samples within a set time in order to have enough to reduce false positives to a tolerable level.

Both, could be true at the same time.