The pack is 22kwhr, with 108 CALB 60Ah batteries. This produces a voltage of 370v. The motor is a no-name 80kw BLDC from China.What sized pack? What motor/controller setup? I am planning my 73 914 conversion and plan to use the new HPEVS AC-75 motor with the 144 volt controller. I am looking at 180ah cells for this build.
Your distance seems rather good for 70mph. I say that because my Leaf can't do 70mph for very long. No chance To get 70 miles at those speeds.
I've been measuring the energy used during freeway drives, which is how I got the 70 at 70 number. The 100 mile range is a guesstimate.
For the 914, you'll probably need to beef up the suspension a bit, and get the bearings cleaned up, and get the wheels properly aligned. All of that will greatly improve your energy burn.