iS IT A SCAM OR HAND HELD TUNERS WORK?
got to be a scam right? or anyone used it and dyno it after?
BMS JB4 Beta For Mercedes-Benz AMG GTS
I have used Renntech in the past and yes they are expensive and great and all that. In this day and age of technology i dont think sending someone my ECM for a tune is necessary.
Just my 0.2.5 cents (adjusted for inflation)



