I didn’t know Aspen caused issues… What exactly was the problem?
When we (the FIA, when i was part of it) introduced 100% 2nd gen bio fuel in 2023, single supplied by P1, the “only” issues we had found were some rubber components’ sensitivity in the sense that they engorged over time (mainly intake gaskets of some manufacturers on float chamber carburators like the Dellorto). With membrane carbs, the small complications came from the membrane themselves drying out and having to be changed slightly more often than with standard fossil fuel.
Apart from that, the fuel itself runs richer than standard, and makes considerable more power across the entire powerband. Close to an additional hp at peak, from what i have been told. Moreover, it has a very high resistance against detonation.
The fuel is more sensitive to changes in atmospheric humidity and temperature, which makes carburation throughout the day more complicated than ussual, but this is why factory teams exist…
in Vegas the temperature may vary a lot between morning, afternoon and night.
If I’m not wrong in 2022 we ran KZ closest to midnight on fridays and saturday and it was freezing.
I think this year Supernats is back to Sunoco…
i usethe app jetting for kz here in the Netherlands and europe and it works perfectly …get the local weather and i get 12 different carb occupancy and below that a graph you can then play with all the variabels so you can see whether you become richer or leaner.
La K98 est une aiguille qui manque de stabilité, je pense que sa partie restante dans le puits en pleine ouverture impacte la carburation suivant la position du clips.
Elle a tendance à souvent détonner “sur l’aiguille” dans des conditions de froid et de pression atmosphérique importante lorsque l’on est à mi-ouverture ou progression. Elle peut être "magique " un jour, et “détonnante” le lendemain …
La U12 est une aiguille très stable à mon goût, il suffit de 2 puits DQ265 et 266 avec une dizaine de GP de 120 à 140, et en principe on trouve toujours le bon setup rapidement.
What sort of inner and outer pilot jets are you running with the U12 setup you mention? That needle has a very different profile from needles like K98 or K28, so curious if you set up the pilot circuits any differently.