I see what you mean Mark on the first run around 6k and agree that it's not ideal. Could it be that this is a previously learned value from before the fuel was changed to the higher octane mixture ? The second run is not so bad, possibly learning upwards in the absence of knock.

The missing boost I referred to is also evident on the first map,
4400rpm target 18.2 Actual 16.5
5200rpm target 16.2 Actual 15.1
Thats taking account of the higher atmospheric pressure on the day and working it back from the absolute values.

Andy

 

Hey

I have been using this fuel for like 3 weeks now so I am sure it would have learned everything it can by now ? or should I do an ecu reset anyway ?

Should I play with the restrictor (I have an adjustable flow valve in plave of restrictor so can adjust it back and forth very very easily) and try and find that extra 1 psi of boost ?

Cheers,
Ray

 

In that case, yes the ECU should have readjusted by now. I wouldn't do a reset unless you plan changing your fuel mix again.

I would also leave the restrictor as it is for now. Ideally your timing maps require adjustment to optimise the amount of +ve knock correction the ECU will allow, especially at higher rpm.
For maximum safety I recommend you stay out of the 6200rpm+ zone until you can determine whether the engine noise being picked up is just background or real knock.

One way to check this would be to reset the ECU and try a run on an even higher octane mix, if the knocklink gets less active and the knock correction advance increases (compare new DD log run with old run) then it is fair to say the ECU was picking up genuine reasons to retard. If the knocklink activity and knock advance stays the same then it is very likely that it is just picking up background noise and its safe to run as you are currently.

Andy

 

I will try that out Andy, thanks

 

The boost in the map from the ECU is in absolute pressure and there is only a VERY slightly difference with the boost on the logs. It looks fine to me.

P.S. Normally an STi engine is VERY quiet, on the Knock Link only the first green en perhaps at high revs the 2nd green. When you see an amber light it is very likely to be det. You could retard the ignition with Delta Dash to see whether it makes any difference! Retard with 3 degrees and look whether you see the amber light again at high revs. This should normally be enough to cure the det.

Mark.

 

Sure it is Mark, thats why you compare it to the absolute pressure recorded by the ECU ie at 4400rpm target boost 2.28bar absolute (33.08psi) actual boost recorded absolute 31.5 so thats still 1.5 psi down (thats equivalent of a ppp upgrade ) Not a problem though, we agree

Andy

 

I understand Andy!

Mark.

 

I want my 1.5 psi back