Pinking/detonation

[Tony Walker]

I assume most people who have there boost pressures turned up still have the knock sensor connected. How much does the knock sensor retard the ignition timing? and how many of us are perhaps using this sensor without even knowing? How good/sensitive is the sensor?

[Nottswoody]

Mine is connected but was it working at time of failure? How would I test this?

[Tony Walker]

Im wondering if its part of the bogging down feeling when changing gear sometimes.

[andybond]

That will be fuelling not det.

[Nottswoody]

Agreed about the feuling but while the engine is out I'm going to check everything properly this time.. How would I check if the knock sensor is working?

[Brigsy]

Knock sensor wont cause bogging on gearchanges that will be fuelling. I think the sensor retards ign by 6 degrees if it senses knock

[Tony Walker]

I agree the main cause is fueling but during this fueling problem i think det may be occuring, this is when my engine destroyed a ring. I felt it bog down going in to fourth at 18psi and that was that. my fueling was a little lean but not massive, what causes this bogging down and are the engines deting at this point?

[andybond]

Unfortunatly AF ratios and det dont always go hand in hand.

Case in point VNTs + Fives. The AFR can be great , but it can still det like mad.

[Tony Walker]

thats because the map at low revs isnt anywhere near retarded enough.

[Brigsy]

Ill bet the bogging down on gear change is down to a 2mm needle jet flooding on gearchange (this is assuming you have one fitted?)

The damage will have been done before that happened mate, as soon as you lift off det stops. You should always have some means of listening for knock when setting up fuelling, to damage a ring landing at only 18psi something is definitely a miss.

Never go too lean on the fuelling either ;) whats your idea of a little bit lean??

[Tony Walker]

high 12s possibly 13 standard needle valve. its not when you lift off its when you re apply the accelerator in a higher gear lower revs and a higher load on the engine.

[Alex]

A little bit on the lean side, T? Maybe try richening things up a bit and see if it still does it?

[Brigsy]

high 12s possibly 13 standard needle valve. its not when you lift off its when you re apply the accelerator in a higher gear lower revs and a higher load on the engine.

High 12's far too lean mate and thats most likely what has caused the damage. You should be aiming for 12.1 on full boost/wot if you want to keep it reliable