hey guys i have the mayhem st as well and i love it.all i have done is drive around in a grassy pasture kind of setting and it loves to haul butt around it.i dont quite have half a gallon through it and it is still strong.i haven't played with it much but i want more speed and after getting used to it's handling characteristics i think i am ready for the bigger restrictor.i need input on what adjustments i will need after the larger restrictor has been put in ie low speed, high speed or idle.i run it at about 220-230 degrees with an infrared temp sensor.now also what clutch or spur gear changes should i make to acquire more speed. i have heard some peole say theirs will wheelie off the start.mine doesnt.what can i do as far as spur/cluth gear changes? thanks guys and keep enjoying this fine truck we have.ps i did install the sportwerks 5mm shock towers and they do look awesome .