Re: It started with a pop
Posted: Sun Sep 26, 2021 8:30 pm
Thanks to Matt for his helpful explanation and PMs.
To answer your questions which may help others.
'What does your afr and colortune tell you?' - If I set the AFR much above 15:1 with the Knecht air filter boxes off, the car does pop back through the carbs. The colortune shows the combustion going off blue to more of a white colour - so this seems to confirm.
I set the AFR to about 14:1 without the Knecht air filter boxes and the car rarely pops - so that seems the max I can tolerate at idle.
At this setting the idle is very stable and can be set to a steady 900rpm quite easily.
However with this setting once the Knechts go back on the AFR drops to around 12.5 to 13:1 - which feels a bit rich to me at idle.
It still idles well with them on but obviously the rpm rises so I need to adjust it back down a little.
This is a little problematic as at this point you can't tell whether the carbs are still balanced side to side ( unless I remove the air filters again to check ).
So the Knechts richen things up significantly on fitment.
At this point the colortune is more blue than white, and my Gunson gaster gives me around 5% or so CO.
I think my plan is to tune the AFR closer to 14:1 with the Knechts on, and then monitor the AFR under different conditions on a run.
Should I be able to buy any petrol any time soon, I will let you know how I get on.
If I can't buy any more fuel then its all a little bit academic
Thanks again
Andrew
To answer your questions which may help others.
'What does your afr and colortune tell you?' - If I set the AFR much above 15:1 with the Knecht air filter boxes off, the car does pop back through the carbs. The colortune shows the combustion going off blue to more of a white colour - so this seems to confirm.
I set the AFR to about 14:1 without the Knecht air filter boxes and the car rarely pops - so that seems the max I can tolerate at idle.
At this setting the idle is very stable and can be set to a steady 900rpm quite easily.
However with this setting once the Knechts go back on the AFR drops to around 12.5 to 13:1 - which feels a bit rich to me at idle.
It still idles well with them on but obviously the rpm rises so I need to adjust it back down a little.
This is a little problematic as at this point you can't tell whether the carbs are still balanced side to side ( unless I remove the air filters again to check ).
So the Knechts richen things up significantly on fitment.
At this point the colortune is more blue than white, and my Gunson gaster gives me around 5% or so CO.
I think my plan is to tune the AFR closer to 14:1 with the Knechts on, and then monitor the AFR under different conditions on a run.
Should I be able to buy any petrol any time soon, I will let you know how I get on.
If I can't buy any more fuel then its all a little bit academic
Thanks again
Andrew