jetting for pistons?

[skyline_898]

i was looking at buying some pistons. either weiscos or the vitos superstocks. the superstocks say that you will need to rejet, and i dont know why. if there the same size pistons, that doesnt change the amount of gas going through. (i am on the stock bore size) will I have to rejet for the weiscos, because dont say anything about it. what will my jetting need to be at? evelation is 600 and its around 30-40 degrees now

[Tim C]

I had to jet a couple sizes bigger when I was running Vito's SS pistons. You need to rejet because of the difference in flow these pistons have - they have bigger windows and change the port timing

[skyline_898]

any idea on what size jets i would need :shrug:

[Tim C]

any idea on what size jets i would need :shrug:

 

 

If all you have is pipes you'd probably be around 280 if your running full airbox lid. I was 300 in summer and 320 in winter but my airbox lid was cut and I had some other mods

[skyline_898]

ok thanks, ill try a 320 main w/o the lid. if its 2 rich ill go down. anything changed with any other jets, ort just leave em