Here is the save (ID:2501155). So the problem is I want to make a engine that has a real piston that moves and can also has a changeable speed. So what I plan to do is have 4 subframes 2 sprk-pscn and 2 sprk-nscn. I have the subframe be pushed by a much simpler and smaller pstn. I found a way around the problem of the pstn moveing the subframe without sticking to the larger pstn by seting the ctype of the small pstn to not move other pstn but now there is a new problem. for some reason the subframe pscn and nscn wont make the pstn move. I dont know whats going on but I don't see a way around this. the idea is to have one set of subframe move the large pstn at a moderate pace when the engines idleing and when the actcelerateor is pressed the other set moves with the first witch causes the large pstn to move at a faster pace. I have tried increaseing the tmp of the large pstn and that did not work. Im quite sure this is a bug but if not can I get some feedback?
Those are called "solid sparks", not "subframes". Subframe refers to the field as a whole of exploiting sub-frame behavior.
Anyway, your solid sparks aren't activating your piston because the CONVs are resetting the PSCN/NSCNs before the PSTN's update function is called. You'll want to arrange them such that the CONVs come after the PSTN in subframe order, e.g. in the row below. You can set the tmp of the CONV to prevent it from converting the BTRY.
(If you don't know what "update function" or "subframe order" etc. means, they're explained in the lesson series at id:2232626.)
By the way, you shouldn't need to use subframe if you're working at time scales larger than 8 frames per cycle.
Thank you for your help. im new to subframe and knew there was a subframe order but did not realise it worked that way.