Just for those who need a clue yes the vtech does engage at 5200 rpm, but maybe you have noticed that it doesn't always kick in on that note now here is the most important two things to remember water temp has to be at 150 F give or take a few degrees that means in the morning you hop in your car and take off without the warmup vtech will not be working the next thing is oil pressure if you are running a qaurt low the vtech will not engage until the pressure is at the right point that means you will probably exceed the normal 5200 rpm engagement until you build the correct oil pressure then it will kick in, but really just don't let your oil level get low the stock vtech contoller is from the ecu witch moniter's the temp & oil pressure to the most fuel efficiant and by gaining instead of losing hp in the high rpm's by engaging the cams into a higher performance level and that is done by the oil pressure opening the cylinoid that is the round little tower thingy two wires should come the tower one is a natural ground and the other comes from the ecu. Now for those who had the patence to read this from the top you can make a vtech light with those two wires comming from the vtech cylinoind tower get a led hell pretty much any light works positive is the one coming from the ecu the other is your ground run it through the fire wall mount it anywhere you want just make sure it is visable baaaaaaaaaaaaaaaaaaaam its smooth then if you just do not know when vtech engages or if it even does, but if you absolutly want full controll of vtech engagement there is a way!!!!!!!!!!!