Hi Tony, I just got the Button head and installed it in my old regular vspec (more than a 1.5 years with I think over six gallons). I tested it on our tracks. All I can say is wow!!! Turned my old vspec into a beast. I can honestly say this thing works and I could swear its like driving a speed.
When i was about to call it a day during my last tank my car stalled dead in the middle, so i was kinda confused cause its running real well. I though maybe the fuel line came off or something. I checked the car everythinngs in place. My next suspect was the clutch. Took it apart, nothing was wrong. I tried rotating the flywheel and its quite gritty so I opened up the engine and saw the piston shattered into several pieces. I was shocked to see that cause I mostly see torn rods but the piston still intact. I approached veterans on tracks and they told me my engine was over compressed becuase of the ping marks on top of the piston and the botton head. I think I shimmed the thing wrong. My friend and I was confused as to what to put in as shim cause the instruction wasnt clear about it. It was written in the instruction not to use both shim together so we can only pick one. I chose the copper one and this is what happed.
Whats the right way to shim this thing? I run a p4 plug and 25% nitro fuel. The intructions told us to use the silver shim for 30% p4 plug so we kinda use the copper. Veteran racers told me just be safe and put both shims first so that the same mishap would not happen again then move from there.
I am sad in a way cause i wanna try my old vspec for longevity. But I thing the shear compression ratio that this button brings smashed it. metal fatigue i guess or over compression the thing imploded. But I am still happy with the button. Imagine what it can do for a speed tuned. I cant let this thing happen to a 500 dollar mill.