Welcome to Part 2 of 3 in my Specialized Turbo S Long Term Review. I feel like this is some of the most essential information that I can apply in one place that will keep Turbo pedalelecs running …
I bet you can ask this dude. He wrote a whole blog for troubleshooting turbo levo problems.
I could not see all of the controller, but there should be some connection for a throttle, even if they didn't intend it that way.
I'd contact an e-bike LBS and ask them if it's possible and what they would charge to install one. Personally, the throttle for me is only for getting up steep paved roads w/o changing wattage levels, and if I did 1000W level 5 it would do the same thing anyway, so it's really not necessary. It's kind of a lazy way to get power, you twist instead of push a button. No real relation to a motorcycle's throttle.