All the mentioned changes will help for sure.
Set the cylinders at a better angle.
Since your cylinders are a larger boar and stroke it will need lots of air quickly.
A separate solenoid per cylinder is a must with, if possible, higher Cv flow.
We got these really quickly using one of the vouchers from FIRST.
http://www.automationdirect.com/adc/...)/AVS-3211-24D
They are 24v and the price was reasonable.. About 20 dollars. Not sure if you are using the older 12v solenoid from previous kits. Some FIRST KOP came with 12v others 24v. You will have to make some adjustments if you are running 12v.
You will have to have the solenoid breakout on the cRio run it.
Ideally, like mentioned, mounted on the cylinder. If not as close as possible!
Air lines after the solenoid have to be filled before any air reaches the cylinder.
Storage of high pressure as well as having working pressure tanks for each cylinder. Try having the low pressure tank as close as you can to the solenoid.
As for venting.
Take off the unused hose fittings!!! You are reducing the flow of escaping air and slowing it down.
We are running a system similar to 842, ( well done by the way 842!)
(2) 10" 1-1/2"bore cylinders and it will consistently hit the high goal at 20 feet away with a release point of 3.5 feet off the floor..
You can look at our Youtube stuff and freeze frame for ideas..
http://www.youtube.com/watch?v=LfKh6...po3XAn15-6TXDg
Send me a message if you have additional questions. I will try to get some photos from the students.
Good luck this season,
Aloha!