RE: Racing a Forza/Tornado
I'm with Nitrosports on the aluminum arms. I've tortured my Tornado and the control arms have never been a problem. My friends Volcano, my sons Caldera 10e have also never just broke arms. I promise you, you've never seen anyone put a Volcano S30 through what my friend has. It's his beater. He has a few other vehicles and just doesn't worry about if he breaks something on it. Now does this mean you won't break an arm while racing? Anything is possible, but I wouldn't worry about it too much, I'd be more concerned about the added weight of the aluminum arms.
Again when we're talking about racing we're concerned about setup as much as anything. I know you dove head first into this hobby like a few of us on here and are truly addicted. When it comes to your suspension, remember the size of your vehicle. It's on the small size so you don't need huge, heavy big bore shocks to get it dialed in. If your lucky, you can find some fatory shocks on eBay from a Losi 810 buggy. These are a huge upgrade compared to what came stock on your Forza. They have good travel and will tune nicely for your buggy. They don't use the same ball mount, they will mount to the stock shock towers with some machine screws.
The Shockwave tranny will bolt in, but your limited with it due to the fact there are no spur gear options. If your really going to make some magic with your Forza, the ability to tune your center drive will be a big factor. Since your pulling out all the stops with this one, I'd start at the center. do some research, find yourself a center drive from something that was designed to work with a .21 engine like your intending to install. I would start my build there and work from the inside out. The Losi .21 and center diff from the 810 buggy would probably be a great start for this project. It comes with the standard 2 piece clutch with the wrap around spring, but they have an optiona flywheel with the three piece clutch.
Remember all the little things that win races. I think you've said you've done some racing...right? So going with the flow is always safe, but sometimes going against the grain can yield great results as well. Remember the simple things like diff fluids. Don't just be happy tuning you diffs like everybody else. Your driving style might be different. Your torque might be different than some of the other guys at the track. You could be overlooking quick gains out of the corners if your not critical enough of your diffs and especially suspension travel.
For me, if your just playing around, any servo that works is good for me. But if your really trying to make this Forza have an edge, think about spending some money on digital servos. As far as the wheels go, I abandoned the buggy wheels on my Tornado and wound up putting bigger tires on it for better ground clearance, so I don't have much info for you on that. Keep us posted, post some picks as you go along. This is going to be a fun project.