I just installed the Rapid Bike Evo (RBE) auto-tune fuel module and wiring harness on my `21 STR and I'm almost giddy with delight after about 50 miles of auto-tuning. It is similar to a Power Commander V but dyno tuning is not required. The RBE "auto-tunes" the factory fuel maps (or any maps) to about 13.5 A/F ratio which, in my case, has resulted in a much smoother, happier engine with considerable improvements in low-to-mid range torque and throttle response. The RBE continues to refine its auto-tuning as you ride and has a USB connector and software to connect a computer for visual display of mapping and control of many functions. The installation is similar to a PCV but...the crank position sensor on my `21 STR is buried beneath the throttle bodies and difficult to access/connect. I got it done only with lots of head scratching and two long needle nose pliers. I do not think the installation is for beginners. The fuel tank and complete air box have to be removed. I've installed several PCV's on other bikes of mine and this unit is superior in my opinion. The instructions said to locate the module under the passenger seat but, because I have a smaller lithium battery, there was just enough room under my seat for the module which made installation easier although I had to remove the two tilt-limiter tabs on the fuel tank mount which was no big deal. It works great for me and I consider it worth every penny! Note: I'm not affiliated with Rapid Bike in any way. Rapid Bike Evo is made in Italy and the USA importer is Cycle Pro in Orlando, Florida. Cycle Pro is very knowledgeable and helpful about the product Cheers!
