why does detonation lower the EGTs?

[A80Avant]

cheers for that!
vasilis

[A80Avant]

I have been reading a bit into this subject again and i have some new questions...

Now that i understand the consept of lower EGTs due to detonation,i read somewhere that if for example you have normal EGTs 815C and you start getting 610C after a new batch of fuel,then you should be concerned about detonation.

I wonder,could you have that difference on EGTs and NOT hear the actual knocking?

Also how big of a difference of EGTs should it actually create a concern for detonation when you dont actaully hear it?Does a difference of 10C-50C create a concern or could that be just the fact that the map has a richer value after certain revs,or there is a boost pressure drop that creates an ease on EGTs towards the end of the rev range?

Could there also be knocking without actually realising it while on WOT,full boost etc?Should the retardation that the motronic does before you reach the actual detonation be felt in your drivers seat?

I know some of these questions may sound silly to some of you,and probably someone will come up and just say: hey man,lower your boost and you'll be fine! ,but im only looking for answers,and this has nothing to do with my car.Since i have never 'felt' or 'heard' detonation before,it would be nice to know a bit more

cheers

[Jonnybravo]

Interesting thread this as you have asked all the questions I also wanted answers for.

A friend of mine who does his own mapping uses one of these :

http://www.phormula.co.uk/KnockMonitor-KS-4.aspx

Paul @ Zen performace uses them for mapping all his engines too.