Mike,
I have the TWM setup which is identical down to the bolts to yours. We just hooked up all the electronics and fired the engine last week. I couldn't drive it at Road America due to a misplaced crossover fuel line discovered on the last day before we trailered to Wisconsin. Mine was the Grey and Copper 40 there. My pedal is tight or stiff as well. I have a few routing issues to work out and an adjustment for the pedal itself. One thing to consider with your pedal is, is the fulcrum of the clevis located before the top of the arc that it goes through when you depress the throttle. These have to be located just before the top of the arc or the cable will bind on its entry/exit to the sheath. Mine is too far ahead of the arc and I will have to alter the rod ends to get it closer to the top of the arc. My setup uses a push pull setup(see DRB#5). Also, I measured the lenght of the cable as it unwinds from the round device on the intake manifold. It measures nearly 3 inches. If you lenghten the shaft at the pedal, the down side is the pedal will need to go further to reach WOT. Three inches is about as long as you want to use. Gets tough on the ankle. The good news is that the work required is less(basic geometry). The other less easily done thing is to increase the radius of the mount on the intake manifold.
I have noticed that to open the throttle bodies at the intake manifold, requires a tremendous effort. Either the springs on the ends of the adjustment rods(idle set screw area) is too stiff or the mechanism that links the throttle bodies is too tight. I will contact TWM today or tomorrow(on call today and tonight) and get their thoughts as they shouold have delt with this before. They are the company that furnished the FI setups to the Roush motors. How do I know? That is what held them up for two weeks when I ordered mine. If they aren't able to help us, then I will contact Roush to see if they experienced this problem and how they handled it. If your is a Roush setup, give them a call and post the response here.
Bill
i did contact thor motorsports abt this issue. (the guy who sold me the TWM.) i asked him abt this and asked where the mechanism springs were and if he has seen this prob b4. he said he hadnt heard of this issue and was going to check to see if he could get a schematics on where the springs are.
my engine is a custom build, so i have not contacted roush.
i did contact olthoff and per merlin he was not aware of any adjustment that could be done, but he has not seen any heavy throttle issues with the TWM.
we did check the cable and didnt find any kinks or sharp bends.
im sure we will look again.