I just installed the Velocity Devices (VDI) Copperhead and did some preliminary testing. My initial reactions are all very positive . My King Quad starts easily, idles better than with the stock ECU and definetely has more low end power. Unfortunately, I also changed my tires at the same time. Although I kept the exact same size, the replacement STI Black Diamonds are much taller. The increased size is changing my effective gear ratio. Even with the taller tires and my limited testing, I can still feel the increased performance from the VDI unit. I did a quick blip of the throttle and the front end lifted with ease. No pulling on the handlebars at all and no throwing my weight backward.

I should add that my King Quad is fully dressed. I have a front and back box and a winch. My front box has two small coolers and the rear box is packed with gear. I also have a full three gallon gas can onboard. I would estimate that with the gear plus my 215 pounds, the total weight is around 1020#.

I wonder what the Copperhead would do on a stripped down machine with a lighter driver?

Weather permitting, I am headed to NEPA to do some further testing on 11/10- 11/12. I will post those results also.

Installation was a breeze. The instructions are straightforward.

I took the opportunity to clean the area before swapping out the ECU and installing the Copperhead.

Lift the seat, remove the old ECU.



Disconnect the white plug.



Jump out the two pins (I used a paper clip)



Verify that you have a horizontal line in the center of the "C" by the "COO"



Put your new Copperhead in place of your old ECU




Ride and have a blast!