I tried out the front wing this afternoon and it was a failure. I was getting downforce, but it made the truck handle weird and it was just too easy to bend it up. I think it was too big of a wing for such a short wheelbase truck. I scrapped that and went with the adding weight idea. I strapped a 1/2" x 2-1/2" socket extension (approx 140 grams) to the front of the chassis and put in 43/45 gearing. This kept the front end down and allowed some better runs. I was able to get up to 73 MPH with this setup before I damaged a tire. One of my HPI Super Nitro belted slicks (part #4598) broke a belt, as best I can tell. Check out the picture and you will see two flat spots while the rest of the tire is good. The tire feels firm due to the belt everywhere except between the two flat spots. Needless to say, that one tire has a pretty bad baloon and wobble now. The additional weight definitely affected the acceleration, but at least I was getting into full throttle. I could tell it is still accelerating slowly after hitting WOT though, so I know there is more in it.
One interesting note...I have been using BrianG's speed calc a lot to try to understand what is happening. I have confirmed that this motor does not seem to want to turn more than about 48k RPM, even with low gearing. This tells me that my 4S setup is making no more than 14.8 volts. Even though the lipos have a nominal voltage of 3.7V/cell, I figured they would be closer to 4.2V/cell when freshly charged. They measure that high right off the charger, but then they must be dipping to 3.7V or lower under load? Maybe this is the result of only having 1800mah of capacity? IF I am going to be limited on voltage, I should have gotten the next higher KV motor. Or, I could just get a single 3S pack to run a 5S setup :)
